diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..39abe13
Binary files /dev/null and b/.DS_Store differ
diff --git a/ossim_source_code/.DS_Store b/ossim_source_code/.DS_Store
new file mode 100644
index 0000000..6b57edf
Binary files /dev/null and b/ossim_source_code/.DS_Store differ
diff --git a/ossim_source_code/.vscode/c_cpp_properties.json b/ossim_source_code/.vscode/c_cpp_properties.json
new file mode 100644
index 0000000..f6526a0
--- /dev/null
+++ b/ossim_source_code/.vscode/c_cpp_properties.json
@@ -0,0 +1,18 @@
+{
+  "configurations": [
+    {
+      "name": "macos-clang-arm64",
+      "includePath": [
+        "${workspaceFolder}/**"
+      ],
+      "compilerPath": "/usr/bin/clang",
+      "cStandard": "${default}",
+      "cppStandard": "c++20",
+      "intelliSenseMode": "macos-clang-arm64",
+      "compilerArgs": [
+        ""
+      ]
+    }
+  ],
+  "version": 4
+}
\ No newline at end of file
diff --git a/ossim_source_code/.vscode/launch.json b/ossim_source_code/.vscode/launch.json
new file mode 100644
index 0000000..5de968d
--- /dev/null
+++ b/ossim_source_code/.vscode/launch.json
@@ -0,0 +1,13 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "C/C++ Runner: Debug Session",
+      "type": "lldb",
+      "request": "launch",
+      "args": [],
+      "cwd": "/Users/admin/Downloads/ossim_source_code/src",
+      "program": "/Users/admin/Downloads/ossim_source_code/src/build/Debug/outDebug"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/ossim_source_code/.vscode/settings.json b/ossim_source_code/.vscode/settings.json
new file mode 100644
index 0000000..7a3b5b2
--- /dev/null
+++ b/ossim_source_code/.vscode/settings.json
@@ -0,0 +1,66 @@
+{
+  "C_Cpp_Runner.cCompilerPath": "clang",
+  "C_Cpp_Runner.cppCompilerPath": "clang++",
+  "C_Cpp_Runner.debuggerPath": "lldb",
+  "C_Cpp_Runner.cStandard": "",
+  "C_Cpp_Runner.cppStandard": "c++20",
+  "C_Cpp_Runner.msvcBatchPath": "",
+  "C_Cpp_Runner.useMsvc": false,
+  "C_Cpp_Runner.warnings": [
+    "-Wall",
+    "-Wextra",
+    "-Wpedantic",
+    "-Wshadow",
+    "-Wformat=2",
+    "-Wcast-align",
+    "-Wconversion",
+    "-Wsign-conversion",
+    "-Wnull-dereference"
+  ],
+  "C_Cpp_Runner.msvcWarnings": [
+    "/W4",
+    "/permissive-",
+    "/w14242",
+    "/w14287",
+    "/w14296",
+    "/w14311",
+    "/w14826",
+    "/w44062",
+    "/w44242",
+    "/w14905",
+    "/w14906",
+    "/w14263",
+    "/w44265",
+    "/w14928"
+  ],
+  "C_Cpp_Runner.enableWarnings": true,
+  "C_Cpp_Runner.warningsAsError": false,
+  "C_Cpp_Runner.compilerArgs": [],
+  "C_Cpp_Runner.linkerArgs": [],
+  "C_Cpp_Runner.includePaths": [],
+  "C_Cpp_Runner.includeSearch": [
+    "*",
+    "**/*"
+  ],
+  "C_Cpp_Runner.excludeSearch": [
+    "**/build",
+    "**/build/**",
+    "**/.*",
+    "**/.*/**",
+    "**/.vscode",
+    "**/.vscode/**"
+  ],
+  "C_Cpp_Runner.useAddressSanitizer": false,
+  "C_Cpp_Runner.useUndefinedSanitizer": false,
+  "C_Cpp_Runner.useLeakSanitizer": false,
+  "C_Cpp_Runner.showCompilationTime": false,
+  "C_Cpp_Runner.useLinkTimeOptimization": false,
+  "C_Cpp_Runner.msvcSecureNoWarnings": false,
+  "git.ignoreLimitWarning": true,
+  "files.associations": {
+    "cstdlib": "cpp",
+    "locale": "cpp",
+    "ostream": "cpp",
+    "new": "cpp"
+  }
+}
\ No newline at end of file
diff --git a/ossim_source_code/Makefile b/ossim_source_code/Makefile
new file mode 100644
index 0000000..f7ed868
--- /dev/null
+++ b/ossim_source_code/Makefile
@@ -0,0 +1,50 @@
+
+INC = -Iinclude
+LIB = -lpthread
+
+SRC = src
+OBJ = obj
+INCLUDE = include
+
+CC = gcc
+DEBUG = -g
+CFLAGS = -Wall -c $(DEBUG)
+LFLAGS = -Wall $(DEBUG)
+
+vpath %.c $(SRC)
+vpath %.h $(INCLUDE)
+
+MAKE = $(CC) $(INC) 
+
+# Object files needed by modules
+MEM_OBJ = $(addprefix $(OBJ)/, paging.o mem.o cpu.o loader.o)
+OS_OBJ = $(addprefix $(OBJ)/, cpu.o mem.o loader.o queue.o os.o sched.o timer.o mm-vm.o mm.o mm-memphy.o)
+SCHED_OBJ = $(addprefix $(OBJ)/, cpu.o loader.o)
+HEADER = $(wildcard $(INCLUDE)/*.h)
+
+all: os
+#mem sched os
+
+# Just compile memory management modules
+mem: $(MEM_OBJ)
+	$(MAKE) $(LFLAGS) $(MEM_OBJ) -o mem $(LIB)
+
+# Just compile scheduler
+sched: $(SCHED_OBJ) $(MEM_OBJ)
+	$(MAKE) $(LFLAGS) $(SCHED_OBJ) $(MEM_OBJ) -o sched $(LIB)
+
+# Compile the whole OS simulation
+os: $(OS_OBJ)
+	$(MAKE) $(LFLAGS) $(OS_OBJ) -o os $(LIB)
+
+$(OBJ)/%.o: %.c ${HEADER} $(OBJ)
+	$(MAKE) $(CFLAGS) $< -o $@
+
+# Prepare objectives container
+$(OBJ):
+	mkdir -p $(OBJ)
+
+clean:
+	rm -f $(OBJ)/*.o os sched mem
+	rm -r $(OBJ)
+
diff --git a/ossim_source_code/include/bitops.h b/ossim_source_code/include/bitops.h
new file mode 100644
index 0000000..0cc9413
--- /dev/null
+++ b/ossim_source_code/include/bitops.h
@@ -0,0 +1,37 @@
+#ifdef CONFIG_64BIT
+#define BITS_PER_LONG 64
+#else
+#define BITS_PER_LONG 32
+#endif /* CONFIG_64BIT */
+
+#define BITS_PER_BYTE           8
+#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
+
+#define BIT(nr)                 (1U << (nr))
+#define BIT_ULL(nr)             (1ULL << (nr))
+#define BIT_MASK(nr)            (1UL << ((nr) % BITS_PER_LONG))
+#define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
+#define BIT_ULL_MASK(nr)        (1ULL << ((nr) % BITS_PER_LONG_LONG))
+#define BIT_ULL_WORD(nr)        ((nr) / BITS_PER_LONG_LONG)
+
+#define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
+
+#define BIT_ULL_MASK(nr)        (1ULL << ((nr) % BITS_PER_LONG_LONG))
+#define BIT_ULL_WORD(nr)        ((nr) / BITS_PER_LONG_LONG)
+
+/*
+ * Create a contiguous bitmask starting at bit position @l and ending at
+ * position @h. For example
+ * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
+ */
+#define GENMASK(h, l) \
+	(((~0U) << (l)) & (~0U >> (BITS_PER_LONG  - (h) - 1)))
+
+#define NBITS2(n) ((n&2)?1:0)
+#define NBITS4(n) ((n&(0xC))?(2+NBITS2(n>>2)):(NBITS2(n)))
+#define NBITS8(n) ((n&0xF0)?(4+NBITS4(n>>4)):(NBITS4(n)))
+#define NBITS16(n) ((n&0xFF00)?(8+NBITS8(n>>8)):(NBITS8(n)))
+#define NBITS32(n) ((n&0xFFFF0000)?(16+NBITS16(n>>16)):(NBITS16(n)))
+#define NBITS(n) (n==0?0:NBITS32(n))
+
+#define EXTRACT_NBITS(nr, h, l) ((nr&GENMASK(h,l)) >> l)
diff --git a/ossim_source_code/include/common.h b/ossim_source_code/include/common.h
new file mode 100644
index 0000000..c1d5a17
--- /dev/null
+++ b/ossim_source_code/include/common.h
@@ -0,0 +1,96 @@
+#ifndef COMMON_H
+#define COMMON_H
+
+/* Define structs and routine could be used by every source files */
+
+#include <stdint.h>
+
+#ifndef OSCFG_H
+#include "os-cfg.h"
+#endif
+
+#ifndef OSMM_H
+#include "os-mm.h"
+#endif
+
+#define ADDRESS_SIZE	20
+#define OFFSET_LEN	10
+#define FIRST_LV_LEN	5
+#define SECOND_LV_LEN	5
+#define SEGMENT_LEN     FIRST_LV_LEN
+#define PAGE_LEN        SECOND_LV_LEN
+
+#define NUM_PAGES	(1 << (ADDRESS_SIZE - OFFSET_LEN))
+#define PAGE_SIZE	(1 << OFFSET_LEN)
+
+enum ins_opcode_t {
+	CALC,	// Just perform calculation, only use CPU
+	ALLOC,	// Allocate memory
+#ifdef MM_PAGING
+	MALLOC, // Allocate dynamic memory
+#endif
+	FREE,	// Deallocated a memory block
+	READ,	// Write data to a byte on memory
+	WRITE	// Read data from a byte on memory
+};
+
+/* instructions executed by the CPU */
+struct inst_t {
+	enum ins_opcode_t opcode;
+	uint32_t arg_0; // Argument lists for instructions
+	uint32_t arg_1;
+	uint32_t arg_2;
+};
+
+struct code_seg_t {
+	struct inst_t * text;
+	uint32_t size;
+};
+
+struct trans_table_t {
+	/* A row in the page table of the second layer */
+	struct  {
+		addr_t v_index; // The index of virtual address
+		addr_t p_index; // The index of physical address
+	} table[1 << SECOND_LV_LEN];
+	int size;
+};
+
+/* Mapping virtual addresses and physical ones */
+struct page_table_t {
+	/* Translation table for the first layer */
+	struct {
+		addr_t v_index;	// Virtual index
+		struct trans_table_t * next_lv;
+	} table[1 << FIRST_LV_LEN];
+	int size;	// Number of row in the first layer
+};
+
+/* PCB, describe information about a process */
+struct pcb_t {
+	uint32_t pid;	// PID
+	uint32_t priority; // Default priority, this legacy (FIXED) value depend on process itself
+	struct code_seg_t * code;	// Code segment
+	addr_t regs[10]; // Registers, store address of allocated regions
+	uint32_t pc; // Program pointer, point to the next instruction
+#ifdef MLQ_SCHED
+	// Priority on execution (if supported), on-fly aka. changeable
+	// and this vale overwrites the default priority when it existed
+	uint32_t prio;     
+#endif
+#ifdef MM_PAGING
+	struct mm_struct *mm;
+	struct memphy_struct *mram;
+	struct memphy_struct **mswp;
+	struct memphy_struct *active_mswp;
+#ifdef MM_PAGING_HEAP_GODOWN
+	uint32_t vmemsz;
+#endif
+#endif
+	struct page_table_t * page_table; // Page table
+	uint32_t bp;	// Break pointer
+
+};
+
+#endif
+
diff --git a/ossim_source_code/include/cpu.h b/ossim_source_code/include/cpu.h
new file mode 100644
index 0000000..0b95b07
--- /dev/null
+++ b/ossim_source_code/include/cpu.h
@@ -0,0 +1,13 @@
+
+#ifndef CPU_H
+#define CPU_H
+
+#include "common.h"
+
+/* Execute an instruction of a process. Return 0
+ * if the instruction is executed successfully.
+ * Otherwise, return 1. */
+int run(struct pcb_t * proc);
+
+#endif
+
diff --git a/ossim_source_code/include/loader.h b/ossim_source_code/include/loader.h
new file mode 100644
index 0000000..8fedc07
--- /dev/null
+++ b/ossim_source_code/include/loader.h
@@ -0,0 +1,9 @@
+#ifndef LOADER_H
+#define LOADER_H
+
+#include "common.h"
+
+struct pcb_t * load(const char * path);
+
+#endif
+
diff --git a/ossim_source_code/include/mem.h b/ossim_source_code/include/mem.h
new file mode 100644
index 0000000..3c2f5a3
--- /dev/null
+++ b/ossim_source_code/include/mem.h
@@ -0,0 +1,32 @@
+#ifndef MEM_H
+#define MEM_H
+
+#include "common.h"
+
+#define RAM_SIZE	(1 << ADDRESS_SIZE)
+
+/* Init related parameters, must be called before being used */
+void init_mem(void);
+
+/* Allocate [size] bytes for process [proc] and return its virtual address.
+ * If we cannot allocate new memory region for this process, return 0 */
+addr_t alloc_mem(uint32_t size, struct pcb_t * proc);
+
+/* Free a memory block having the first byte at [address] used by
+ * process [proc]. Return 0 if [address] is valid. Otherwise, return 1 */
+int free_mem(addr_t address, struct pcb_t * proc);
+
+/* Read 1 byte memory pointed by [address] used by process [proc] and
+ * save it to [data].
+ * If the given [address] is valid, return 0. Otherwise, return 1 */
+int read_mem(addr_t address, struct pcb_t * proc, BYTE * data);
+
+/* Write [data] to 1 byte on the memory pointed by [address] of process
+ * [proc]. If given [address] is valid, return 0. Otherwise, return 1 */
+int write_mem(addr_t address, struct pcb_t * proc, BYTE data);
+
+void dump(void);
+
+#endif
+
+
diff --git a/ossim_source_code/include/mm.h b/ossim_source_code/include/mm.h
new file mode 100644
index 0000000..e7d9094
--- /dev/null
+++ b/ossim_source_code/include/mm.h
@@ -0,0 +1,163 @@
+#ifndef MM_H
+
+#include "bitops.h"
+#include "common.h"
+
+/* CPU Bus definition */
+#define PAGING_CPU_BUS_WIDTH 22 /* 22bit bus - MAX SPACE 4MB */
+#define PAGING_PAGESZ  256      /* 256B or 8-bits PAGE NUMBER */
+#define PAGING_MEMRAMSZ BIT(10) /* 1MB */
+#define PAGING_PAGE_ALIGNSZ(sz) (DIV_ROUND_UP(sz,PAGING_PAGESZ) *PAGING_PAGESZ)
+
+#define PAGING_MEMSWPSZ BIT(14) /* 16MB */
+#define PAGING_SWPFPN_OFFSET 5  
+#define PAGING_MAX_PGN  (DIV_ROUND_UP(BIT(PAGING_CPU_BUS_WIDTH),PAGING_PAGESZ))
+
+#define PAGING_SBRK_INIT_SZ PAGING_PAGESZ
+/* PTE BIT */
+#define PAGING_PTE_PRESENT_MASK BIT(31) 
+#define PAGING_PTE_SWAPPED_MASK BIT(30)
+#define PAGING_PTE_RESERVE_MASK BIT(29)
+#define PAGING_PTE_DIRTY_MASK BIT(28)
+#define PAGING_PTE_EMPTY01_MASK BIT(14)
+#define PAGING_PTE_EMPTY02_MASK BIT(13)
+
+/* PTE BIT PRESENT */
+#define PAGING_PTE_SET_PRESENT(pte) (pte=pte|PAGING_PTE_PRESENT_MASK)
+#define PAGING_PTE_PAGE_PRESENT(pte) (pte&PAGING_PTE_PRESENT_MASK)
+
+/* USRNUM */
+#define PAGING_PTE_USRNUM_LOBIT 15
+#define PAGING_PTE_USRNUM_HIBIT 27
+/* FPN */
+#define PAGING_PTE_FPN_LOBIT 0
+#define PAGING_PTE_FPN_HIBIT 12
+/* SWPTYP */
+#define PAGING_PTE_SWPTYP_LOBIT 0
+#define PAGING_PTE_SWPTYP_HIBIT 4
+/* SWPOFF */
+#define PAGING_PTE_SWPOFF_LOBIT 5
+#define PAGING_PTE_SWPOFF_HIBIT 25
+
+/* PTE masks */
+#define PAGING_PTE_USRNUM_MASK GENMASK(PAGING_PTE_USRNUM_HIBIT,PAGING_PTE_USRNUM_LOBIT)
+#define PAGING_PTE_FPN_MASK    GENMASK(PAGING_PTE_FPN_HIBIT,PAGING_PTE_FPN_LOBIT)
+#define PAGING_PTE_SWPTYP_MASK GENMASK(PAGING_PTE_SWPTYP_HIBIT,PAGING_PTE_SWPTYP_LOBIT)
+#define PAGING_PTE_SWPOFF_MASK GENMASK(PAGING_PTE_SWPOFF_HIBIT,PAGING_PTE_SWPOFF_LOBIT)
+
+/* Extract PTE */
+#define PAGING_PTE_OFFST(pte) GETVAL(pte,PAGING_OFFST_MASK,PAGING_ADDR_OFFST_LOBIT)
+#define PAGING_PTE_PGN(pte)   GETVAL(pte,PAGING_PGN_MASK,PAGING_ADDR_PGN_LOBIT)
+#define PAGING_PTE_FPN(pte)   GETVAL(pte,PAGING_PTE_FPN_MASK,PAGING_PTE_FPN_LOBIT)
+#define PAGING_PTE_SWP(pte)   GETVAL(pte,PAGING_PTE_SWPOFF_MASK,PAGING_SWPFPN_OFFSET)
+
+/* OFFSET */
+#define PAGING_ADDR_OFFST_LOBIT 0
+#define PAGING_ADDR_OFFST_HIBIT (NBITS(PAGING_PAGESZ) - 1)
+
+/* PAGE Num */
+#define PAGING_ADDR_PGN_LOBIT NBITS(PAGING_PAGESZ)
+#define PAGING_ADDR_PGN_HIBIT (PAGING_CPU_BUS_WIDTH - 1)
+
+/* Frame PHY Num */
+#define PAGING_ADDR_FPN_LOBIT NBITS(PAGING_PAGESZ)
+#define PAGING_ADDR_FPN_HIBIT (NBITS(PAGING_MEMRAMSZ) - 1)
+
+/* SWAPFPN */
+#define PAGING_SWP_LOBIT NBITS(PAGING_PAGESZ)
+#define PAGING_SWP_HIBIT (NBITS(PAGING_MEMSWPSZ) - 1)
+
+/* Value operators */
+#define SETBIT(v,mask) (v=v|mask)
+#define CLRBIT(v,mask) (v=v&~mask)
+
+#define SETVAL(v,value,mask,offst) (v=(v&~mask)|((value<<offst)&mask))
+#define GETVAL(v,mask,offst) ((v&mask)>>offst)
+
+/* Other masks */
+#define PAGING_OFFST_MASK  GENMASK(PAGING_ADDR_OFFST_HIBIT,PAGING_ADDR_OFFST_LOBIT)
+#define PAGING_PGN_MASK  GENMASK(PAGING_ADDR_PGN_HIBIT,PAGING_ADDR_PGN_LOBIT)
+#define PAGING_FPN_MASK  GENMASK(PAGING_ADDR_FPN_HIBIT,PAGING_ADDR_FPN_LOBIT)
+#define PAGING_SWP_MASK  GENMASK(PAGING_SWP_HIBIT,PAGING_SWP_LOBIT)
+
+/* Extract OFFSET */
+//#define PAGING_OFFST(x)  ((x&PAGING_OFFST_MASK) >> PAGING_ADDR_OFFST_LOBIT)
+#define PAGING_OFFST(x)  GETVAL(x,PAGING_OFFST_MASK,PAGING_ADDR_OFFST_LOBIT)
+/* Extract Page Number*/
+#define PAGING_PGN(x)  GETVAL(x,PAGING_PGN_MASK,PAGING_ADDR_PGN_LOBIT)
+/* Extract FramePHY Number*/
+#define PAGING_FPN(x)  GETVAL(x,PAGING_FPN_MASK,PAGING_ADDR_FPN_LOBIT)
+/* Extract SWAPFPN */
+#define PAGING_PGN(x)  GETVAL(x,PAGING_PGN_MASK,PAGING_ADDR_PGN_LOBIT)
+/* Extract SWAPTYPE */
+#define PAGING_FPN(x)  GETVAL(x,PAGING_FPN_MASK,PAGING_ADDR_FPN_LOBIT)
+
+/* Memory range operator */
+/* TODO implement the INCLUDE checking mechanism - currently dummy op only */
+#define INCLUDE(x1,x2,y1,y2) (0)
+/* TODO implement the OVERLAP checking mechanism - currently dummy op only */
+#define OVERLAP(x1,x2,y1,y2) (1)
+
+/* VM region prototypes */
+struct vm_rg_struct * init_vm_rg(int rg_start, int rg_endi, int vmaid);
+int enlist_vm_rg_node(struct vm_rg_struct **rglist, struct vm_rg_struct* rgnode);
+int enlist_pgn_node(struct pgn_t **pgnlist, int pgn);
+int vmap_page_range(struct pcb_t *caller, int addr, int pgnum, 
+                    struct framephy_struct *frames, struct vm_rg_struct *ret_rg);
+int vm_map_ram(struct pcb_t *caller, int astart, int send, int mapstart, int incpgnum, struct vm_rg_struct *ret_rg);
+int alloc_pages_range(struct pcb_t *caller, int incpgnum, struct framephy_struct **frm_lst);
+int __swap_cp_page(struct memphy_struct *mpsrc, int srcfpn,
+                struct memphy_struct *mpdst, int dstfpn) ;
+int pte_set_fpn(uint32_t *pte, int fpn);
+int pte_set_swap(uint32_t *pte, int swptyp, int swpoff);
+int init_pte(uint32_t *pte,
+             int pre,    // present
+             int fpn,    // FPN
+             int drt,    // dirty
+             int swp,    // swap
+             int swptyp, // swap type
+             int swpoff); //swap offset
+int __alloc(struct pcb_t *caller, int vmaid, int rgid, int size, int *alloc_addr);
+int __free(struct pcb_t *caller, int rgid);
+int __read(struct pcb_t *caller, int rgid, int offset, BYTE *data);
+int __write(struct pcb_t *caller, int rgid, int offset, BYTE value);
+int init_mm(struct mm_struct *mm, struct pcb_t *caller);
+
+/* VM prototypes */
+int pgalloc(struct pcb_t *proc, uint32_t size, uint32_t reg_index);
+int pgmalloc(struct pcb_t *proc, uint32_t size, uint32_t reg_index);
+int pgfree_data(struct pcb_t *proc, uint32_t reg_index);
+int pgread(
+		struct pcb_t * proc, // Process executing the instruction
+		uint32_t source, // Index of source register
+		uint32_t offset, // Source address = [source] + [offset]
+		uint32_t destination);
+int pgwrite(
+		struct pcb_t * proc, // Process executing the instruction
+		BYTE data, // Data to be wrttien into memory
+		uint32_t destination, // Index of destination register
+		uint32_t offset);
+/* Local VM prototypes */
+struct vm_rg_struct * get_symrg_byid(struct mm_struct* mm, int rgid);
+int validate_overlap_vm_area(struct pcb_t *caller, int vmaid, int vmastart, int vmaend);
+int get_free_vmrg_area(struct pcb_t *caller, int vmaid, int size, struct vm_rg_struct *newrg);
+int inc_vma_limit(struct pcb_t *caller, int vmaid, int inc_sz, int* inc_limit_ret);
+int find_victim_page(struct mm_struct* mm, int *pgn);
+struct vm_area_struct *get_vma_by_num(struct mm_struct *mm, int vmaid);
+
+/* MEM/PHY protypes */
+int MEMPHY_get_freefp(struct memphy_struct *mp, int *fpn);
+int MEMPHY_put_freefp(struct memphy_struct *mp, int fpn);
+int MEMPHY_read(struct memphy_struct * mp, int addr, BYTE *value);
+int MEMPHY_write(struct memphy_struct * mp, int addr, BYTE data);
+int MEMPHY_dump(struct memphy_struct * mp);
+int init_memphy(struct memphy_struct *mp, int max_size, int randomflg);
+/* DEBUG */
+int print_list_fp(struct framephy_struct *fp);
+int print_list_rg(struct vm_rg_struct *rg);
+int print_list_vma(struct vm_area_struct *rg);
+
+
+int print_list_pgn(struct pgn_t *ip);
+int print_pgtbl(struct pcb_t *ip, uint32_t start, uint32_t end);
+#endif
diff --git a/ossim_source_code/include/os-cfg.h b/ossim_source_code/include/os-cfg.h
new file mode 100644
index 0000000..d5034e0
--- /dev/null
+++ b/ossim_source_code/include/os-cfg.h
@@ -0,0 +1,15 @@
+#ifndef OSCFG_H
+#define OSCFG_H
+
+#define MLQ_SCHED 1
+#define MAX_PRIO 140
+
+#define MM_PAGING
+#define MM_PAGING_HEAP_GODOWN
+// #define MM_FIXED_MEMSZ
+#define VMDBG 1
+#define MMDBG 1
+#define IODUMP 1
+#define PAGETBL_DUMP 1
+
+#endif
diff --git a/ossim_source_code/include/os-mm.h b/ossim_source_code/include/os-mm.h
new file mode 100644
index 0000000..beef90e
--- /dev/null
+++ b/ossim_source_code/include/os-mm.h
@@ -0,0 +1,88 @@
+#ifndef OSMM_H
+#define OSMM_H
+
+#define MM_PAGING
+#define PAGING_MAX_MMSWP 4 /* max number of supported swapped space */
+#define PAGING_MAX_SYMTBL_SZ 30
+
+typedef char BYTE;
+typedef uint32_t addr_t;
+//typedef unsigned int uint32_t;
+
+struct pgn_t{
+   int pgn;
+   struct pgn_t *pg_next; 
+};
+
+/*
+ *  Memory region struct
+ */
+struct vm_rg_struct {
+   int vmaid;
+
+   unsigned long rg_start;
+   unsigned long rg_end;
+
+   struct vm_rg_struct *rg_next;
+};
+
+/*
+ *  Memory area struct
+ */
+struct vm_area_struct {
+   unsigned long vm_id;
+   unsigned long vm_start;
+   unsigned long vm_end;
+
+   unsigned long sbrk;
+/*
+ * Derived field
+ * unsigned long vm_limit = vm_end - vm_start
+ */
+   struct mm_struct *vm_mm;
+   
+   struct vm_rg_struct *vm_freerg_list;
+   struct vm_area_struct *vm_next;
+};
+
+/* 
+ * Memory management struct
+ */
+struct mm_struct {
+   uint32_t *pgd;
+
+   struct vm_area_struct *mmap;
+
+   /* Currently we support a fixed number of symbol */
+   struct vm_rg_struct symrgtbl[PAGING_MAX_SYMTBL_SZ];
+
+   /* list of free page */
+   struct pgn_t *fifo_pgn;
+};
+
+/*
+ * FRAME/MEM PHY struct
+ */
+struct framephy_struct { 
+   int fpn;
+   struct framephy_struct *fp_next;
+
+   /* Resereed for tracking allocated framed */
+   struct mm_struct* owner;
+};
+
+struct memphy_struct {
+   /* Basic field of data and size */
+   BYTE *storage;
+   int maxsz;
+   
+   /* Sequential device fields */ 
+   int rdmflg;
+   int cursor;
+
+   /* Management structure */
+   struct framephy_struct *free_fp_list;
+   struct framephy_struct *used_fp_list;
+};
+
+#endif
diff --git a/ossim_source_code/include/queue.h b/ossim_source_code/include/queue.h
new file mode 100644
index 0000000..d26881c
--- /dev/null
+++ b/ossim_source_code/include/queue.h
@@ -0,0 +1,22 @@
+
+#ifndef QUEUE_H
+#define QUEUE_H
+
+#include "common.h"
+
+#define MAX_QUEUE_SIZE 10
+
+struct queue_t {
+	int count_slot;
+	struct pcb_t * proc[MAX_QUEUE_SIZE];
+	int size;
+};
+
+void enqueue(struct queue_t * q, struct pcb_t * proc);
+
+struct pcb_t * dequeue(struct queue_t * q);
+
+int empty(struct queue_t * q);
+
+#endif
+
diff --git a/ossim_source_code/include/sched.h b/ossim_source_code/include/sched.h
new file mode 100644
index 0000000..d252c72
--- /dev/null
+++ b/ossim_source_code/include/sched.h
@@ -0,0 +1,28 @@
+#ifndef QUEUE_H
+#define QUEUE_H
+
+#include "common.h"
+
+#ifndef MLQ_SCHED
+#define MLQ_SCHED
+#endif
+
+//#define MAX_PRIO 139
+
+int queue_empty(void);
+
+void init_scheduler(void);
+void finish_scheduler(void);
+
+/* Get the next process from ready queue */
+struct pcb_t * get_proc(void);
+
+/* Put a process back to run queue */
+void put_proc(struct pcb_t * proc);
+
+/* Add a new process to ready queue */
+void add_proc(struct pcb_t * proc);
+
+#endif
+
+
diff --git a/ossim_source_code/include/timer.h b/ossim_source_code/include/timer.h
new file mode 100644
index 0000000..e480b66
--- /dev/null
+++ b/ossim_source_code/include/timer.h
@@ -0,0 +1,28 @@
+#ifndef TIMER_H
+#define TIMER_H
+
+#include <pthread.h>
+#include <stdint.h>
+
+struct timer_id_t {
+	int done;
+	int fsh;
+	pthread_cond_t event_cond;
+	pthread_mutex_t event_lock;
+	pthread_cond_t timer_cond;
+	pthread_mutex_t timer_lock;
+};
+
+void start_timer();
+
+void stop_timer();
+
+struct timer_id_t * attach_event();
+
+void detach_event(struct timer_id_t * event);
+
+void next_slot(struct timer_id_t* timer_id);
+
+uint64_t current_time();
+
+#endif
diff --git a/ossim_source_code/input/os_0_mlq_paging b/ossim_source_code/input/os_0_mlq_paging
new file mode 100644
index 0000000..6872297
--- /dev/null
+++ b/ossim_source_code/input/os_0_mlq_paging
@@ -0,0 +1,4 @@
+6 2 4
+1048576 16777216 0 0 0 3145728
+0 p0s 0
+2 p1s 15
diff --git a/ossim_source_code/input/os_1_mlq_paging b/ossim_source_code/input/os_1_mlq_paging
new file mode 100644
index 0000000..0068caf
--- /dev/null
+++ b/ossim_source_code/input/os_1_mlq_paging
@@ -0,0 +1,10 @@
+2 4 8
+1048576 16777216 0 0 0 3145728
+1 p0s  130
+2 s3  39
+4 m1s  15
+6 s2  120
+7 m0s  120
+9 p1s  15
+11 s0 38
+16 s1 0
diff --git a/ossim_source_code/input/os_1_mlq_paging_small_1K b/ossim_source_code/input/os_1_mlq_paging_small_1K
new file mode 100644
index 0000000..a5788e4
--- /dev/null
+++ b/ossim_source_code/input/os_1_mlq_paging_small_1K
@@ -0,0 +1,10 @@
+2 4 8
+2048 16777216 0 0 0 3145728
+1 p0s  130
+2 s3  39
+4 m1s  15
+6 s2  120
+7 m0s  120
+9 p1s  15
+11 s0 38
+16 s1 0
diff --git a/ossim_source_code/input/os_1_mlq_paging_small_4K b/ossim_source_code/input/os_1_mlq_paging_small_4K
new file mode 100644
index 0000000..bd6af03
--- /dev/null
+++ b/ossim_source_code/input/os_1_mlq_paging_small_4K
@@ -0,0 +1,10 @@
+2 4 8
+4096 16777216 0 0 0 3145728
+1 p0s  130
+2 s3   39
+4 m1s  15
+6 s2   120
+7 m0s  120
+9 p1s  15
+11 s0  38
+16 s1  0
diff --git a/ossim_source_code/input/os_1_singleCPU_mlq b/ossim_source_code/input/os_1_singleCPU_mlq
new file mode 100644
index 0000000..98efc7e
--- /dev/null
+++ b/ossim_source_code/input/os_1_singleCPU_mlq
@@ -0,0 +1,9 @@
+2 1  8
+1 s4   4
+2 s3   3
+4 m1s  2
+6 s2   3
+7 m0s  3
+9 p1s  2
+11 s0  1
+16 s1  0
diff --git a/ossim_source_code/input/os_1_singleCPU_mlq_paging b/ossim_source_code/input/os_1_singleCPU_mlq_paging
new file mode 100644
index 0000000..99e0a04
--- /dev/null
+++ b/ossim_source_code/input/os_1_singleCPU_mlq_paging
@@ -0,0 +1,10 @@
+2 1  8
+1048576 16777216 0 0 0 3145728
+1 s4  4
+2 s3  3
+4 m1s  2
+6 s2  3
+7 m0s  3
+9 p1s  2
+11 s0 1
+16 s1 0
diff --git a/ossim_source_code/input/proc/m0s b/ossim_source_code/input/proc/m0s
new file mode 100644
index 0000000..3466b3a
--- /dev/null
+++ b/ossim_source_code/input/proc/m0s
@@ -0,0 +1,8 @@
+1 7
+alloc 300 0
+alloc 100 1
+free 0
+alloc 100 2 
+malloc 100 3
+write 102 1 20
+write 1 2 1000
diff --git a/ossim_source_code/input/proc/m1s b/ossim_source_code/input/proc/m1s
new file mode 100644
index 0000000..b3b24a6
--- /dev/null
+++ b/ossim_source_code/input/proc/m1s
@@ -0,0 +1,8 @@
+1 7
+alloc 300 0
+alloc 100 1
+free 0
+alloc 100 2
+malloc 100 2
+free 2
+free 1
diff --git a/ossim_source_code/input/proc/p0s b/ossim_source_code/input/proc/p0s
new file mode 100644
index 0000000..7c443f9
--- /dev/null
+++ b/ossim_source_code/input/proc/p0s
@@ -0,0 +1,15 @@
+1 14
+calc
+alloc 300 0
+malloc 300 4
+free 0
+alloc 100 1
+write 100 1 20
+read 1 20 20
+write 102 2 20
+read 2 20 20
+write 103 3 20
+read 3 20 20
+calc
+free 4
+calc
diff --git a/ossim_source_code/input/proc/p1s b/ossim_source_code/input/proc/p1s
new file mode 100644
index 0000000..79c5fba
--- /dev/null
+++ b/ossim_source_code/input/proc/p1s
@@ -0,0 +1,12 @@
+1 10
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
diff --git a/ossim_source_code/input/proc/p2s b/ossim_source_code/input/proc/p2s
new file mode 100644
index 0000000..2d9336d
--- /dev/null
+++ b/ossim_source_code/input/proc/p2s
@@ -0,0 +1,14 @@
+20 13
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
diff --git a/ossim_source_code/input/proc/p3s b/ossim_source_code/input/proc/p3s
new file mode 100644
index 0000000..08a2128
--- /dev/null
+++ b/ossim_source_code/input/proc/p3s
@@ -0,0 +1,18 @@
+7 17
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
diff --git a/ossim_source_code/input/proc/s0 b/ossim_source_code/input/proc/s0
new file mode 100644
index 0000000..6186100
--- /dev/null
+++ b/ossim_source_code/input/proc/s0
@@ -0,0 +1,16 @@
+12 15
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
diff --git a/ossim_source_code/input/proc/s1 b/ossim_source_code/input/proc/s1
new file mode 100644
index 0000000..8614b76
--- /dev/null
+++ b/ossim_source_code/input/proc/s1
@@ -0,0 +1,8 @@
+20 7
+calc
+calc
+calc
+calc
+calc
+calc
+calc
diff --git a/ossim_source_code/input/proc/s2 b/ossim_source_code/input/proc/s2
new file mode 100644
index 0000000..2d9336d
--- /dev/null
+++ b/ossim_source_code/input/proc/s2
@@ -0,0 +1,14 @@
+20 13
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
diff --git a/ossim_source_code/input/proc/s3 b/ossim_source_code/input/proc/s3
new file mode 100644
index 0000000..08a2128
--- /dev/null
+++ b/ossim_source_code/input/proc/s3
@@ -0,0 +1,18 @@
+7 17
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
diff --git a/ossim_source_code/input/proc/s4 b/ossim_source_code/input/proc/s4
new file mode 100644
index 0000000..79dfde8
--- /dev/null
+++ b/ossim_source_code/input/proc/s4
@@ -0,0 +1,31 @@
+20 30
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
+calc
diff --git a/ossim_source_code/input/sched b/ossim_source_code/input/sched
new file mode 100644
index 0000000..33c50ef
--- /dev/null
+++ b/ossim_source_code/input/sched
@@ -0,0 +1,4 @@
+4 2 3
+0 p1s
+1 p2s
+2 p3s
diff --git a/ossim_source_code/input/sched_0 b/ossim_source_code/input/sched_0
new file mode 100644
index 0000000..ae979fd
--- /dev/null
+++ b/ossim_source_code/input/sched_0
@@ -0,0 +1,3 @@
+2 1 2
+0 s0 137
+4 s1 138
diff --git a/ossim_source_code/input/sched_1 b/ossim_source_code/input/sched_1
new file mode 100644
index 0000000..c7fac37
--- /dev/null
+++ b/ossim_source_code/input/sched_1
@@ -0,0 +1,5 @@
+2 1 4
+0 s0
+4 s1
+6 s2
+7 s3
diff --git a/ossim_source_code/obj/cpu.o b/ossim_source_code/obj/cpu.o
new file mode 100644
index 0000000..4a5586b
Binary files /dev/null and b/ossim_source_code/obj/cpu.o differ
diff --git a/ossim_source_code/obj/loader.o b/ossim_source_code/obj/loader.o
new file mode 100644
index 0000000..6c7bebb
Binary files /dev/null and b/ossim_source_code/obj/loader.o differ
diff --git a/ossim_source_code/obj/mem.o b/ossim_source_code/obj/mem.o
new file mode 100644
index 0000000..f258d18
Binary files /dev/null and b/ossim_source_code/obj/mem.o differ
diff --git a/ossim_source_code/obj/mm-memphy.o b/ossim_source_code/obj/mm-memphy.o
new file mode 100644
index 0000000..f63706c
Binary files /dev/null and b/ossim_source_code/obj/mm-memphy.o differ
diff --git a/ossim_source_code/obj/mm-vm.o b/ossim_source_code/obj/mm-vm.o
new file mode 100644
index 0000000..f5dd1f1
Binary files /dev/null and b/ossim_source_code/obj/mm-vm.o differ
diff --git a/ossim_source_code/obj/mm.o b/ossim_source_code/obj/mm.o
new file mode 100644
index 0000000..75aaf47
Binary files /dev/null and b/ossim_source_code/obj/mm.o differ
diff --git a/ossim_source_code/obj/os.o b/ossim_source_code/obj/os.o
new file mode 100644
index 0000000..0f729d1
Binary files /dev/null and b/ossim_source_code/obj/os.o differ
diff --git a/ossim_source_code/obj/queue.o b/ossim_source_code/obj/queue.o
new file mode 100644
index 0000000..47a4309
Binary files /dev/null and b/ossim_source_code/obj/queue.o differ
diff --git a/ossim_source_code/obj/sched.o b/ossim_source_code/obj/sched.o
new file mode 100644
index 0000000..471d174
Binary files /dev/null and b/ossim_source_code/obj/sched.o differ
diff --git a/ossim_source_code/obj/timer.o b/ossim_source_code/obj/timer.o
new file mode 100644
index 0000000..a8cc5c9
Binary files /dev/null and b/ossim_source_code/obj/timer.o differ
diff --git a/ossim_source_code/os b/ossim_source_code/os
new file mode 100755
index 0000000..d436028
Binary files /dev/null and b/ossim_source_code/os differ
diff --git a/ossim_source_code/output/os_0_mlq_paging.output b/ossim_source_code/output/os_0_mlq_paging.output
new file mode 100644
index 0000000..87d78bc
--- /dev/null
+++ b/ossim_source_code/output/os_0_mlq_paging.output
@@ -0,0 +1,78 @@
+Time slot   0
+ld_routine
+	Loaded a process at input/proc/p0s, PID: 1 PRIO: 0
+	CPU 0: Dispatched process  1
+Time slot   1
+Time slot   2
+	Loaded a process at input/proc/p1s, PID: 2 PRIO: 15
+Time slot   3
+	Loaded a process at input/proc/p1s, PID: 3 PRIO: 0
+Time slot   4
+	CPU 1: Dispatched process  2
+	Loaded a process at input/proc/p1s, PID: 4 PRIO: 0
+Time slot   5
+write region=1 offset=20 value=100
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot   6
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  1
+read region=1 offset=20 value=100
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot   7
+write region=2 offset=20 value=102
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot   8
+read region=2 offset=20 value=102
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot   9
+write region=3 offset=20 value=103
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot  10
+	CPU 1: Put process  2 to run queue
+	CPU 1: Dispatched process  4
+	CPU 0: Processed  1 has finished
+	CPU 0: Dispatched process  3
+Time slot  11
+Time slot  12
+Time slot  13
+Time slot  14
+Time slot  15
+Time slot  16
+	CPU 1: Put process  4 to run queue
+	CPU 1: Dispatched process  2
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  17
+Time slot  18
+Time slot  19
+Time slot  20
+	CPU 0: Processed  3 has finished
+	CPU 0: Dispatched process  4
+	CPU 1: Processed  2 has finished
+	CPU 1 stopped
+Time slot  21
+Time slot  22
+Time slot  23
+Time slot  24
+	CPU 0: Processed  4 has finished
+	CPU 0 stopped
diff --git a/ossim_source_code/output/os_1_mlq_paging.output b/ossim_source_code/output/os_1_mlq_paging.output
new file mode 100644
index 0000000..2f675f0
--- /dev/null
+++ b/ossim_source_code/output/os_1_mlq_paging.output
@@ -0,0 +1,173 @@
+Time slot   0
+ld_routine
+Time slot   1
+	Loaded a process at input/proc/p0s, PID: 1 PRIO: 130
+Time slot   2
+	CPU 1: Dispatched process  1
+	Loaded a process at input/proc/s3, PID: 2 PRIO: 39
+Time slot   3
+	CPU 0: Dispatched process  2
+Time slot   4
+	CPU 1: Put process  1 to run queue
+	Loaded a process at input/proc/m1s, PID: 3 PRIO: 15
+	CPU 3: Dispatched process  1
+Time slot   5
+	CPU 2: Dispatched process  3
+	CPU 0: Put process  2 to run queue
+Time slot   6
+	CPU 0: Dispatched process  2
+	Loaded a process at input/proc/s2, PID: 4 PRIO: 120
+	CPU 3: Put process  1 to run queue
+Time slot   7
+	CPU 1: Dispatched process  4
+	CPU 2: Put process  3 to run queue
+	CPU 2: Dispatched process  1
+	Loaded a process at input/proc/m0s, PID: 5 PRIO: 120
+	CPU 3: Dispatched process  3
+Time slot   8
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  5
+write region=1 offset=20 value=100
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot   9
+	CPU 1: Put process  4 to run queue
+	CPU 1: Dispatched process  2
+	CPU 2: Put process  1 to run queue
+	CPU 2: Dispatched process  4
+	Loaded a process at input/proc/p1s, PID: 6 PRIO: 15
+	CPU 3: Put process  3 to run queue
+	CPU 3: Dispatched process  1
+read region=1 offset=20 value=100
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot  10
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  3
+write region=2 offset=20 value=102
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot  11
+	CPU 1: Put process  2 to run queue
+	CPU 1: Dispatched process  6
+	CPU 2: Put process  4 to run queue
+	CPU 2: Dispatched process  2
+	Loaded a process at input/proc/s0, PID: 7 PRIO: 38
+	CPU 3: Put process  1 to run queue
+	CPU 3: Dispatched process  4
+Time slot  12
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  5
+Time slot  13
+	CPU 2: Put process  2 to run queue
+	CPU 2: Dispatched process  1
+read region=2 offset=20 value=102
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+	CPU 1: Put process  6 to run queue
+	CPU 1: Dispatched process  6
+	CPU 3: Put process  4 to run queue
+	CPU 3: Dispatched process  3
+Time slot  14
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  7
+write region=3 offset=20 value=103
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot  15
+	CPU 1: Put process  6 to run queue
+	CPU 1: Dispatched process  2
+	CPU 2: Processed  1 has finished
+	CPU 2: Dispatched process  4
+	CPU 3: Processed  3 has finished
+	CPU 3: Dispatched process  5
+write region=1 offset=20 value=102
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: 80000006
+Time slot  16
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+	Loaded a process at input/proc/s1, PID: 8 PRIO: 0
+write region=2 offset=1000 value=1
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: 80000006
+Time slot  17
+	CPU 2: Put process  4 to run queue
+	CPU 2: Dispatched process  7
+	CPU 1: Put process  2 to run queue
+	CPU 1: Dispatched process  4
+	CPU 3: Put process  5 to run queue
+	CPU 3: Dispatched process  8
+Time slot  18
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  2
+Time slot  19
+	CPU 2: Put process  7 to run queue
+	CPU 2: Dispatched process  5
+write region=0 offset=0 value=0
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: c0000000
+	CPU 1: Put process  4 to run queue
+	CPU 1: Dispatched process  6
+	CPU 0: Processed  2 has finished
+	CPU 0: Dispatched process  7
+	CPU 3: Put process  8 to run queue
+	CPU 3: Dispatched process  4
+Time slot  20
+	CPU 2: Processed  5 has finished
+	CPU 2: Dispatched process  8
+Time slot  21
+	CPU 1: Put process  6 to run queue
+	CPU 1 stopped
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+	CPU 3: Processed  4 has finished
+	CPU 3: Dispatched process  7
+Time slot  22
+	CPU 2: Put process  8 to run queue
+	CPU 2 stopped
+Time slot  23
+	CPU 0: Processed  6 has finished
+	CPU 0: Dispatched process  8
+	CPU 3: Put process  7 to run queue
+	CPU 3 stopped
+Time slot  24
+Time slot  25
+	CPU 0: Put process  8 to run queue
+	CPU 0: Dispatched process  7
+Time slot  26
+Time slot  27
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  8
+Time slot  28
+	CPU 0: Processed  8 has finished
+	CPU 0: Dispatched process  7
+Time slot  29
+Time slot  30
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  7
+Time slot  31
+Time slot  32
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  7
+Time slot  33
+	CPU 0: Processed  7 has finished
+	CPU 0 stopped
diff --git a/ossim_source_code/output/os_1_mlq_paging_small_1K.output b/ossim_source_code/output/os_1_mlq_paging_small_1K.output
new file mode 100644
index 0000000..cb2fb07
--- /dev/null
+++ b/ossim_source_code/output/os_1_mlq_paging_small_1K.output
@@ -0,0 +1,171 @@
+Time slot   0
+ld_routine
+Time slot   1
+	Loaded a process at input/proc/p0s, PID: 1 PRIO: 130
+	CPU 1: Dispatched process  1
+Time slot   2
+	Loaded a process at input/proc/s3, PID: 2 PRIO: 39
+Time slot   3
+	CPU 2: Dispatched process  2
+	CPU 1: Put process  1 to run queue
+	CPU 3: Dispatched process  1
+Time slot   4
+	Loaded a process at input/proc/m1s, PID: 3 PRIO: 15
+Time slot   5
+	CPU 2: Put process  2 to run queue
+	CPU 0: Dispatched process  3
+	CPU 1: Dispatched process  2
+	CPU 3: Put process  1 to run queue
+Time slot   6
+	CPU 2: Dispatched process  1
+	Loaded a process at input/proc/s2, PID: 4 PRIO: 120
+Time slot   7
+write region=1 offset=20 value=100
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+	CPU 1: Put process  2 to run queue
+	CPU 1: Dispatched process  4
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  2
+	Loaded a process at input/proc/m0s, PID: 5 PRIO: 120
+	CPU 3: Dispatched process  3
+Time slot   8
+	CPU 2: Put process  1 to run queue
+	CPU 2: Dispatched process  5
+Time slot   9
+	CPU 1: Put process  4 to run queue
+	CPU 1: Dispatched process  1
+read region=1 offset=20 value=100
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  4
+	Loaded a process at input/proc/p1s, PID: 6 PRIO: 15
+	CPU 3: Put process  3 to run queue
+	CPU 3: Dispatched process  2
+Time slot  10
+	CPU 2: Put process  5 to run queue
+	CPU 2: Dispatched process  3
+write region=2 offset=20 value=102
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot  11
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  6
+	CPU 1: Put process  1 to run queue
+	CPU 1: Dispatched process  4
+	Loaded a process at input/proc/s0, PID: 7 PRIO: 38
+	CPU 3: Put process  2 to run queue
+	CPU 3: Dispatched process  5
+Time slot  12
+	CPU 2: Put process  3 to run queue
+	CPU 2: Dispatched process  1
+read region=2 offset=20 value=102
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot  13
+	CPU 1: Put process  4 to run queue
+	CPU 1: Dispatched process  3
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  7
+write region=3 offset=20 value=103
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+	CPU 3: Put process  5 to run queue
+	CPU 3: Dispatched process  2
+Time slot  14
+	CPU 2: Processed  1 has finished
+	CPU 2: Dispatched process  4
+Time slot  15
+	CPU 1: Processed  3 has finished
+	CPU 1: Dispatched process  5
+write region=1 offset=20 value=102
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: 80000006
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+	CPU 3: Put process  2 to run queue
+	CPU 3: Dispatched process  7
+Time slot  16
+write region=2 offset=1000 value=1
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: 80000006
+	CPU 2: Put process  4 to run queue
+	CPU 2: Dispatched process  2
+	Loaded a process at input/proc/s1, PID: 8 PRIO: 0
+Time slot  17
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  4
+	CPU 1: Put process  5 to run queue
+	CPU 1: Dispatched process  8
+	CPU 2: Processed  2 has finished
+	CPU 2: Dispatched process  6
+	CPU 3: Put process  7 to run queue
+	CPU 3: Dispatched process  5
+write region=0 offset=0 value=0
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: c0000000
+Time slot  18
+	CPU 3: Processed  5 has finished
+	CPU 3: Dispatched process  7
+Time slot  19
+	CPU 2: Put process  6 to run queue
+	CPU 2 stopped
+	CPU 1: Put process  8 to run queue
+	CPU 1: Dispatched process  6
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  8
+Time slot  20
+	CPU 3: Put process  7 to run queue
+	CPU 3: Dispatched process  4
+Time slot  21
+	CPU 1: Put process  6 to run queue
+	CPU 1: Dispatched process  7
+	CPU 0: Put process  8 to run queue
+	CPU 0: Dispatched process  6
+Time slot  22
+	CPU 3: Processed  4 has finished
+	CPU 3: Dispatched process  8
+Time slot  23
+	CPU 1: Put process  7 to run queue
+	CPU 1 stopped
+	CPU 0: Processed  6 has finished
+	CPU 0: Dispatched process  7
+Time slot  24
+	CPU 3: Put process  8 to run queue
+	CPU 3 stopped
+Time slot  25
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  8
+Time slot  26
+	CPU 0: Processed  8 has finished
+	CPU 0: Dispatched process  7
+Time slot  27
+Time slot  28
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  7
+Time slot  29
+Time slot  30
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  7
+Time slot  31
+	CPU 0: Processed  7 has finished
+	CPU 0 stopped
diff --git a/ossim_source_code/output/os_1_mlq_paging_small_4K.output b/ossim_source_code/output/os_1_mlq_paging_small_4K.output
new file mode 100644
index 0000000..25afa10
--- /dev/null
+++ b/ossim_source_code/output/os_1_mlq_paging_small_4K.output
@@ -0,0 +1,172 @@
+Time slot   0
+ld_routine
+Time slot   1
+	Loaded a process at input/proc/p0s, PID: 1 PRIO: 130
+	CPU 1: Dispatched process  1
+Time slot   2
+	Loaded a process at input/proc/s3, PID: 2 PRIO: 39
+Time slot   3
+	CPU 2: Dispatched process  2
+	CPU 1: Put process  1 to run queue
+	CPU 3: Dispatched process  1
+Time slot   4
+	Loaded a process at input/proc/m1s, PID: 3 PRIO: 15
+Time slot   5
+	CPU 2: Put process  2 to run queue
+	CPU 0: Dispatched process  3
+	CPU 1: Dispatched process  2
+	CPU 3: Put process  1 to run queue
+Time slot   6
+	CPU 2: Dispatched process  1
+	Loaded a process at input/proc/s2, PID: 4 PRIO: 120
+Time slot   7
+write region=1 offset=20 value=100
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+	CPU 1: Put process  2 to run queue
+	CPU 1: Dispatched process  4
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  2
+	Loaded a process at input/proc/m0s, PID: 5 PRIO: 120
+	CPU 3: Dispatched process  3
+Time slot   8
+	CPU 2: Put process  1 to run queue
+	CPU 2: Dispatched process  5
+Time slot   9
+	CPU 1: Put process  4 to run queue
+	CPU 1: Dispatched process  1
+read region=1 offset=20 value=100
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  4
+	Loaded a process at input/proc/p1s, PID: 6 PRIO: 15
+	CPU 3: Put process  3 to run queue
+	CPU 3: Dispatched process  2
+Time slot  10
+	CPU 2: Put process  5 to run queue
+	CPU 2: Dispatched process  3
+write region=2 offset=20 value=102
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot  11
+	CPU 1: Put process  1 to run queue
+	CPU 1: Dispatched process  6
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+	Loaded a process at input/proc/s0, PID: 7 PRIO: 38
+	CPU 3: Put process  2 to run queue
+	CPU 3: Dispatched process  5
+Time slot  12
+	CPU 2: Put process  3 to run queue
+	CPU 2: Dispatched process  1
+read region=2 offset=20 value=102
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+Time slot  13
+	CPU 1: Put process  6 to run queue
+	CPU 1: Dispatched process  6
+write region=3 offset=20 value=103
+print_pgtbl: 0 - 1024
+00000000: 80000001
+00000004: 80000000
+00000008: 80000003
+00000012: 80000002
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  3
+	CPU 3: Put process  5 to run queue
+	CPU 3: Dispatched process  7
+Time slot  14
+	CPU 2: Processed  1 has finished
+	CPU 2: Dispatched process  2
+Time slot  15
+	CPU 1: Put process  6 to run queue
+	CPU 1: Dispatched process  4
+	CPU 0: Processed  3 has finished
+	CPU 0: Dispatched process  5
+write region=1 offset=20 value=102
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: 80000006
+	CPU 3: Put process  7 to run queue
+	CPU 3: Dispatched process  6
+Time slot  16
+	CPU 2: Put process  2 to run queue
+	CPU 2: Dispatched process  7
+write region=2 offset=1000 value=1
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: 80000006
+	Loaded a process at input/proc/s1, PID: 8 PRIO: 0
+Time slot  17
+	CPU 1: Put process  4 to run queue
+	CPU 1: Dispatched process  2
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  4
+	CPU 3: Put process  6 to run queue
+	CPU 3: Dispatched process  5
+write region=0 offset=0 value=0
+print_pgtbl: 0 - 512
+00000000: 80000007
+00000004: c0000000
+Time slot  18
+	CPU 2: Put process  7 to run queue
+	CPU 2: Dispatched process  8
+	CPU 1: Processed  2 has finished
+	CPU 1: Dispatched process  6
+	CPU 3: Processed  5 has finished
+	CPU 3: Dispatched process  7
+Time slot  19
+	CPU 0: Put process  4 to run queue
+	CPU 0 stopped
+Time slot  20
+	CPU 2: Put process  8 to run queue
+	CPU 2: Dispatched process  4
+	CPU 1: Put process  6 to run queue
+	CPU 1: Dispatched process  8
+	CPU 3: Put process  7 to run queue
+	CPU 3: Dispatched process  6
+Time slot  21
+Time slot  22
+	CPU 2: Processed  4 has finished
+	CPU 2: Dispatched process  7
+	CPU 1: Put process  8 to run queue
+	CPU 1 stopped
+	CPU 3: Processed  6 has finished
+	CPU 3: Dispatched process  8
+Time slot  23
+Time slot  24
+	CPU 2: Put process  7 to run queue
+	CPU 2 stopped
+	CPU 3: Put process  8 to run queue
+	CPU 3: Dispatched process  7
+Time slot  25
+Time slot  26
+	CPU 3: Put process  7 to run queue
+	CPU 3: Dispatched process  8
+Time slot  27
+	CPU 3: Processed  8 has finished
+	CPU 3: Dispatched process  7
+Time slot  28
+Time slot  29
+	CPU 3: Put process  7 to run queue
+	CPU 3: Dispatched process  7
+Time slot  30
+Time slot  31
+	CPU 3: Put process  7 to run queue
+	CPU 3: Dispatched process  7
+Time slot  32
+	CPU 3: Processed  7 has finished
+	CPU 3 stopped
diff --git a/ossim_source_code/output/os_1_singleCPU_mlq.output b/ossim_source_code/output/os_1_singleCPU_mlq.output
new file mode 100644
index 0000000..65a13db
--- /dev/null
+++ b/ossim_source_code/output/os_1_singleCPU_mlq.output
@@ -0,0 +1,185 @@
+Time slot   0
+ld_routine
+Time slot   1
+	Loaded a process at input/proc/s4, PID: 1 PRIO: 4
+Time slot   2
+	Loaded a process at input/proc/s3, PID: 2 PRIO: 3
+Time slot   3
+	CPU 0: Dispatched process  1
+Time slot   4
+	Loaded a process at input/proc/m1s, PID: 3 PRIO: 2
+Time slot   5
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot   6
+	Loaded a process at input/proc/s2, PID: 4 PRIO: 3
+Time slot   7
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+	Loaded a process at input/proc/m0s, PID: 5 PRIO: 3
+Time slot   8
+Time slot   9
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  3
+	Loaded a process at input/proc/p1s, PID: 6 PRIO: 2
+Time slot  10
+Time slot  11
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  4
+	Loaded a process at input/proc/s0, PID: 7 PRIO: 1
+Time slot  12
+Time slot  13
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  14
+Time slot  15
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  16
+	Loaded a process at input/proc/s1, PID: 8 PRIO: 0
+Time slot  17
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  18
+Time slot  19
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  20
+Time slot  21
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  22
+Time slot  23
+	CPU 0: Processed  4 has finished
+	CPU 0: Dispatched process  2
+Time slot  24
+Time slot  25
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  26
+Time slot  27
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  28
+Time slot  29
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  30
+Time slot  31
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  32
+	CPU 0: Processed  2 has finished
+	CPU 0: Dispatched process  5
+Time slot  33
+Time slot  34
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  1
+Time slot  35
+Time slot  36
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  8
+Time slot  37
+Time slot  38
+	CPU 0: Put process  8 to run queue
+	CPU 0: Dispatched process  7
+Time slot  39
+Time slot  40
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  3
+Time slot  41
+Time slot  42
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  43
+Time slot  44
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  45
+Time slot  46
+	CPU 0: Processed  3 has finished
+	CPU 0: Dispatched process  6
+Time slot  47
+Time slot  48
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  5
+Time slot  49
+Time slot  50
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  1
+Time slot  51
+	CPU 0: Processed  1 has finished
+	CPU 0: Dispatched process  8
+Time slot  52
+Time slot  53
+	CPU 0: Put process  8 to run queue
+	CPU 0: Dispatched process  7
+Time slot  54
+Time slot  55
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+Time slot  56
+Time slot  57
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  5
+write region=1 offset=20 value=102
+print_pgtbl: 0 - 512
+00000000: 80000003
+00000004: 80000002
+Time slot  58
+write region=2 offset=1000 value=1
+print_pgtbl: 0 - 512
+00000000: 80000003
+00000004: 80000002
+Time slot  59
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  8
+Time slot  60
+Time slot  61
+	CPU 0: Put process  8 to run queue
+	CPU 0: Dispatched process  7
+Time slot  62
+Time slot  63
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+Time slot  64
+Time slot  65
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  5
+write region=0 offset=0 value=0
+print_pgtbl: 0 - 512
+00000000: 80000003
+00000004: c0000000
+Time slot  66
+	CPU 0: Processed  5 has finished
+	CPU 0: Dispatched process  8
+Time slot  67
+	CPU 0: Processed  8 has finished
+	CPU 0: Dispatched process  7
+Time slot  68
+Time slot  69
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+Time slot  70
+Time slot  71
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  7
+Time slot  72
+Time slot  73
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+Time slot  74
+Time slot  75
+	CPU 0: Processed  6 has finished
+	CPU 0: Dispatched process  7
+Time slot  76
+Time slot  77
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  7
+Time slot  78
+Time slot  79
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  7
+Time slot  80
+	CPU 0: Processed  7 has finished
+	CPU 0 stopped
diff --git a/ossim_source_code/output/os_1_singleCPU_mlq_paging.output b/ossim_source_code/output/os_1_singleCPU_mlq_paging.output
new file mode 100644
index 0000000..65a13db
--- /dev/null
+++ b/ossim_source_code/output/os_1_singleCPU_mlq_paging.output
@@ -0,0 +1,185 @@
+Time slot   0
+ld_routine
+Time slot   1
+	Loaded a process at input/proc/s4, PID: 1 PRIO: 4
+Time slot   2
+	Loaded a process at input/proc/s3, PID: 2 PRIO: 3
+Time slot   3
+	CPU 0: Dispatched process  1
+Time slot   4
+	Loaded a process at input/proc/m1s, PID: 3 PRIO: 2
+Time slot   5
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot   6
+	Loaded a process at input/proc/s2, PID: 4 PRIO: 3
+Time slot   7
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+	Loaded a process at input/proc/m0s, PID: 5 PRIO: 3
+Time slot   8
+Time slot   9
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  3
+	Loaded a process at input/proc/p1s, PID: 6 PRIO: 2
+Time slot  10
+Time slot  11
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  4
+	Loaded a process at input/proc/s0, PID: 7 PRIO: 1
+Time slot  12
+Time slot  13
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  14
+Time slot  15
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  16
+	Loaded a process at input/proc/s1, PID: 8 PRIO: 0
+Time slot  17
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  18
+Time slot  19
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  20
+Time slot  21
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  22
+Time slot  23
+	CPU 0: Processed  4 has finished
+	CPU 0: Dispatched process  2
+Time slot  24
+Time slot  25
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  26
+Time slot  27
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  28
+Time slot  29
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  30
+Time slot  31
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  32
+	CPU 0: Processed  2 has finished
+	CPU 0: Dispatched process  5
+Time slot  33
+Time slot  34
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  1
+Time slot  35
+Time slot  36
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  8
+Time slot  37
+Time slot  38
+	CPU 0: Put process  8 to run queue
+	CPU 0: Dispatched process  7
+Time slot  39
+Time slot  40
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  3
+Time slot  41
+Time slot  42
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  43
+Time slot  44
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  45
+Time slot  46
+	CPU 0: Processed  3 has finished
+	CPU 0: Dispatched process  6
+Time slot  47
+Time slot  48
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  5
+Time slot  49
+Time slot  50
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  1
+Time slot  51
+	CPU 0: Processed  1 has finished
+	CPU 0: Dispatched process  8
+Time slot  52
+Time slot  53
+	CPU 0: Put process  8 to run queue
+	CPU 0: Dispatched process  7
+Time slot  54
+Time slot  55
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+Time slot  56
+Time slot  57
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  5
+write region=1 offset=20 value=102
+print_pgtbl: 0 - 512
+00000000: 80000003
+00000004: 80000002
+Time slot  58
+write region=2 offset=1000 value=1
+print_pgtbl: 0 - 512
+00000000: 80000003
+00000004: 80000002
+Time slot  59
+	CPU 0: Put process  5 to run queue
+	CPU 0: Dispatched process  8
+Time slot  60
+Time slot  61
+	CPU 0: Put process  8 to run queue
+	CPU 0: Dispatched process  7
+Time slot  62
+Time slot  63
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+Time slot  64
+Time slot  65
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  5
+write region=0 offset=0 value=0
+print_pgtbl: 0 - 512
+00000000: 80000003
+00000004: c0000000
+Time slot  66
+	CPU 0: Processed  5 has finished
+	CPU 0: Dispatched process  8
+Time slot  67
+	CPU 0: Processed  8 has finished
+	CPU 0: Dispatched process  7
+Time slot  68
+Time slot  69
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+Time slot  70
+Time slot  71
+	CPU 0: Put process  6 to run queue
+	CPU 0: Dispatched process  7
+Time slot  72
+Time slot  73
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  6
+Time slot  74
+Time slot  75
+	CPU 0: Processed  6 has finished
+	CPU 0: Dispatched process  7
+Time slot  76
+Time slot  77
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  7
+Time slot  78
+Time slot  79
+	CPU 0: Put process  7 to run queue
+	CPU 0: Dispatched process  7
+Time slot  80
+	CPU 0: Processed  7 has finished
+	CPU 0 stopped
diff --git a/ossim_source_code/output/sched.output b/ossim_source_code/output/sched.output
new file mode 100644
index 0000000..edfe4cf
--- /dev/null
+++ b/ossim_source_code/output/sched.output
@@ -0,0 +1,42 @@
+Time slot   0
+ld_routine
+	Loaded a process at input/proc/p1s, PID: 1 PRIO: 1
+	CPU 1: Dispatched process  1
+Time slot   1
+	Loaded a process at input/proc/p1s, PID: 2 PRIO: 0
+Time slot   2
+	Loaded a process at input/proc/p1s, PID: 3 PRIO: 0
+Time slot   3
+	CPU 0: Dispatched process  3
+Time slot   4
+	CPU 1: Put process  1 to run queue
+	CPU 1: Dispatched process  2
+Time slot   5
+Time slot   6
+Time slot   7
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  1
+Time slot   8
+	CPU 1: Put process  2 to run queue
+	CPU 1: Dispatched process  2
+Time slot   9
+Time slot  10
+Time slot  11
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  3
+Time slot  12
+	CPU 1: Put process  2 to run queue
+	CPU 1: Dispatched process  1
+Time slot  13
+Time slot  14
+	CPU 1: Processed  1 has finished
+	CPU 1: Dispatched process  2
+Time slot  15
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  16
+	CPU 1: Processed  2 has finished
+	CPU 1 stopped
+Time slot  17
+	CPU 0: Processed  3 has finished
+	CPU 0 stopped
diff --git a/ossim_source_code/output/sched_0.output b/ossim_source_code/output/sched_0.output
new file mode 100644
index 0000000..0676714
--- /dev/null
+++ b/ossim_source_code/output/sched_0.output
@@ -0,0 +1,68 @@
+Time slot   0
+ld_routine
+	Loaded a process at input/proc/s0, PID: 1 PRIO: 4
+Time slot   1
+	CPU 0: Dispatched process  1
+	Loaded a process at input/proc/s0, PID: 2 PRIO: 0
+Time slot   2
+Time slot   3
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  1
+Time slot   4
+Time slot   5
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot   6
+Time slot   7
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot   8
+Time slot   9
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  10
+Time slot  11
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  12
+Time slot  13
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  14
+Time slot  15
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  16
+Time slot  17
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  18
+Time slot  19
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  20
+Time slot  21
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  22
+Time slot  23
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  24
+Time slot  25
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  26
+Time slot  27
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  28
+	CPU 0: Processed  1 has finished
+	CPU 0: Dispatched process  2
+Time slot  29
+Time slot  30
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  31
+	CPU 0: Processed  2 has finished
+	CPU 0 stopped
diff --git a/ossim_source_code/output/sched_1.output b/ossim_source_code/output/sched_1.output
new file mode 100644
index 0000000..9c338f7
--- /dev/null
+++ b/ossim_source_code/output/sched_1.output
@@ -0,0 +1,132 @@
+Time slot   0
+ld_routine
+	Loaded a process at input/proc/s0, PID: 1 PRIO: 4
+Time slot   1
+	CPU 0: Dispatched process  1
+	Loaded a process at input/proc/s0, PID: 2 PRIO: 0
+Time slot   2
+	Loaded a process at input/proc/s0, PID: 3 PRIO: 0
+Time slot   3
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  1
+	Loaded a process at input/proc/s0, PID: 4 PRIO: 0
+Time slot   4
+Time slot   5
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  4
+Time slot   6
+Time slot   7
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot   8
+Time slot   9
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  10
+Time slot  11
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  12
+Time slot  13
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  14
+Time slot  15
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  16
+Time slot  17
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  18
+Time slot  19
+	CPU 0: Put process  4 to run queue
+	CPU 0: Dispatched process  4
+Time slot  20
+	CPU 0: Processed  4 has finished
+	CPU 0: Dispatched process  3
+Time slot  21
+Time slot  22
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  23
+Time slot  24
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  25
+Time slot  26
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  27
+Time slot  28
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  29
+Time slot  30
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  31
+Time slot  32
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  33
+Time slot  34
+	CPU 0: Put process  3 to run queue
+	CPU 0: Dispatched process  3
+Time slot  35
+	CPU 0: Processed  3 has finished
+	CPU 0: Dispatched process  2
+Time slot  36
+Time slot  37
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  38
+Time slot  39
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  40
+Time slot  41
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  42
+Time slot  43
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  44
+Time slot  45
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  46
+Time slot  47
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  48
+Time slot  49
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  50
+Time slot  51
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  52
+Time slot  53
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  54
+Time slot  55
+	CPU 0: Put process  1 to run queue
+	CPU 0: Dispatched process  2
+Time slot  56
+Time slot  57
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  1
+Time slot  58
+	CPU 0: Processed  1 has finished
+	CPU 0: Dispatched process  2
+Time slot  59
+Time slot  60
+	CPU 0: Put process  2 to run queue
+	CPU 0: Dispatched process  2
+Time slot  61
+	CPU 0: Processed  2 has finished
+	CPU 0 stopped
diff --git a/ossim_source_code/src/cpu.c b/ossim_source_code/src/cpu.c
new file mode 100644
index 0000000..b8deb25
--- /dev/null
+++ b/ossim_source_code/src/cpu.c
@@ -0,0 +1,102 @@
+
+#include "cpu.h"
+#include "mem.h"
+#include "mm.h"
+
+int calc(struct pcb_t * proc) {
+	return ((unsigned long)proc & 0UL);
+}
+
+int alloc(struct pcb_t * proc, uint32_t size, uint32_t reg_index) {
+	addr_t addr = alloc_mem(size, proc);
+	if (addr == 0) {
+		return 1;
+	}else{
+		proc->regs[reg_index] = addr;
+		return 0;
+	}
+}
+
+int free_data(struct pcb_t * proc, uint32_t reg_index) {
+	return free_mem(proc->regs[reg_index], proc);
+}
+
+int read(
+		struct pcb_t * proc, // Process executing the instruction
+		uint32_t source, // Index of source register
+		uint32_t offset, // Source address = [source] + [offset]
+		uint32_t destination) { // Index of destination register
+	
+	BYTE data;
+	if (read_mem(proc->regs[source] + offset, proc,	&data)) {
+		proc->regs[destination] = data;
+		return 0;		
+	}else{
+		return 1;
+	}
+}
+
+int write(
+		struct pcb_t * proc, // Process executing the instruction
+		BYTE data, // Data to be wrttien into memory
+		uint32_t destination, // Index of destination register
+		uint32_t offset) { 	// Destination address =
+					// [destination] + [offset]
+	return write_mem(proc->regs[destination] + offset, proc, data);
+} 
+
+int run(struct pcb_t * proc) {
+	/* Check if Program Counter point to the proper instruction */
+	if (proc->pc >= proc->code->size) {
+		return 1;
+	}
+	
+	struct inst_t ins = proc->code->text[proc->pc];
+	proc->pc++;
+	int stat = 1;
+	switch (ins.opcode) {
+	case CALC:
+		stat = calc(proc);
+		break;
+	case ALLOC:
+#ifdef MM_PAGING
+		stat = pgalloc(proc, ins.arg_0, ins.arg_1);
+
+#else
+		stat = alloc(proc, ins.arg_0, ins.arg_1);
+#endif
+		break;
+#ifdef MM_PAGING
+	case MALLOC:
+		stat = pgmalloc(proc, ins.arg_0, ins.arg_1);
+		break;
+#endif
+	case FREE:
+#ifdef MM_PAGING
+		stat = pgfree_data(proc, ins.arg_0);
+#else
+		stat = free_data(proc, ins.arg_0);
+#endif
+		break;
+	case READ:
+#ifdef MM_PAGING
+		stat = pgread(proc, ins.arg_0, ins.arg_1, ins.arg_2);
+#else
+		stat = read(proc, ins.arg_0, ins.arg_1, ins.arg_2);
+#endif
+		break;
+	case WRITE:
+#ifdef MM_PAGING
+		stat = pgwrite(proc, ins.arg_0, ins.arg_1, ins.arg_2);
+#else
+		stat = write(proc, ins.arg_0, ins.arg_1, ins.arg_2);
+#endif
+		break;
+	default:
+		stat = 1;
+	}
+	return stat;
+
+}
+
+
diff --git a/ossim_source_code/src/loader.c b/ossim_source_code/src/loader.c
new file mode 100644
index 0000000..5f8e56a
--- /dev/null
+++ b/ossim_source_code/src/loader.c
@@ -0,0 +1,108 @@
+
+#include "loader.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static uint32_t avail_pid = 1;
+
+#define OPT_CALC	"calc"
+#define OPT_ALLOC	"alloc"
+#define OPT_FREE	"free"
+#define OPT_READ	"read"
+#define OPT_WRITE	"write"
+#ifdef MM_PAGING
+#define OPT_MALLOC	"malloc"
+#endif
+
+static enum ins_opcode_t get_opcode(char * opt) {
+	if (!strcmp(opt, OPT_CALC)) {
+		return CALC;
+	}else if (!strcmp(opt, OPT_ALLOC)) {
+		return ALLOC;
+#ifdef MM_PAGING
+	}else if (!strcmp(opt, OPT_MALLOC)) {
+		return MALLOC;
+#endif
+	}else if (!strcmp(opt, OPT_FREE)) {
+		return FREE;
+	}else if (!strcmp(opt, OPT_READ)) {
+		return READ;
+	}else if (!strcmp(opt, OPT_WRITE)) {
+		return WRITE;
+	}else{
+		printf("Opcode: %s\n", opt);
+		exit(1);
+	}
+}
+
+struct pcb_t * load(const char * path) {
+	/* Create new PCB for the new process */
+	struct pcb_t * proc = (struct pcb_t * )malloc(sizeof(struct pcb_t));
+	proc->pid = avail_pid;
+	avail_pid++;
+	proc->page_table =
+		(struct page_table_t*)malloc(sizeof(struct page_table_t));
+	proc->bp = PAGE_SIZE;
+	proc->pc = 0;
+
+	/* Read process code from file */
+	FILE * file;
+	// printf(path);
+	if ((file = fopen(path, "r")) == NULL) {
+		printf("Cannot find process description at '%s'\n", path);
+		exit(1);		
+	}
+	char opcode[10];
+	proc->code = (struct code_seg_t*)malloc(sizeof(struct code_seg_t));
+	fscanf(file, "%u %u", &proc->priority, &proc->code->size);
+	proc->code->text = (struct inst_t*)malloc(
+		sizeof(struct inst_t) * proc->code->size
+	);
+	uint32_t i = 0;
+	for (i = 0; i < proc->code->size; i++) {
+		fscanf(file, "%s", opcode);
+		proc->code->text[i].opcode = get_opcode(opcode);
+		switch(proc->code->text[i].opcode) {
+		case CALC:
+			break;
+		case ALLOC:
+			fscanf(
+				file,
+				"%u %u\n",
+				&proc->code->text[i].arg_0,
+				&proc->code->text[i].arg_1
+			);
+			break;
+#ifdef MM_PAGING
+		case MALLOC:
+			fscanf(
+				file,
+				"%u %u\n",
+				&proc->code->text[i].arg_0,
+				&proc->code->text[i].arg_1
+			);
+#endif
+		case FREE:
+			fscanf(file, "%u\n", &proc->code->text[i].arg_0);
+			break;
+		case READ:
+		case WRITE:
+			fscanf(
+				file,
+				"%u %u %u\n",
+				&proc->code->text[i].arg_0,
+				&proc->code->text[i].arg_1,
+				&proc->code->text[i].arg_2
+			);
+			break;	
+		default:
+			printf("Opcode: %s\n", opcode);
+			exit(1);
+		}
+	}
+	return proc;
+}
+
+
+
diff --git a/ossim_source_code/src/mem.c b/ossim_source_code/src/mem.c
new file mode 100644
index 0000000..187108f
--- /dev/null
+++ b/ossim_source_code/src/mem.c
@@ -0,0 +1,173 @@
+
+#include "mem.h"
+#include "stdlib.h"
+#include "string.h"
+#include <pthread.h>
+#include <stdio.h>
+
+static BYTE _ram[RAM_SIZE];
+
+static struct {
+	uint32_t proc;	// ID of process currently uses this page
+	int index;	// Index of the page in the list of pages allocated
+			// to the process.
+	int next;	// The next page in the list. -1 if it is the last
+			// page.
+} _mem_stat [NUM_PAGES];
+
+static pthread_mutex_t mem_lock;
+
+void init_mem(void) {
+	memset(_mem_stat, 0, sizeof(*_mem_stat) * NUM_PAGES);
+	memset(_ram, 0, sizeof(BYTE) * RAM_SIZE);
+	pthread_mutex_init(&mem_lock, NULL);
+}
+
+/* get offset of the virtual address */
+static addr_t get_offset(addr_t addr) {
+	return addr & ~((~0U) << OFFSET_LEN);
+}
+
+/* get the first layer index */
+static addr_t get_first_lv(addr_t addr) {
+	return addr >> (OFFSET_LEN + PAGE_LEN);
+}
+
+/* get the second layer index */
+static addr_t get_second_lv(addr_t addr) {
+	return (addr >> OFFSET_LEN) - (get_first_lv(addr) << PAGE_LEN);
+}
+
+/* Search for page table table from the a segment table */
+static struct trans_table_t * get_trans_table(
+		addr_t index, 	// Segment level index
+		struct page_table_t * page_table) { // first level table
+	
+	/* DO NOTHING HERE. This mem is obsoleted */
+
+	int i;
+	for (i = 0; i < page_table->size; i++) {
+		// Enter your code here
+	}
+	return NULL;
+
+}
+
+/* Translate virtual address to physical address. If [virtual_addr] is valid,
+ * return 1 and write its physical counterpart to [physical_addr].
+ * Otherwise, return 0 */
+static int translate(
+		addr_t virtual_addr, 	// Given virtual address
+		addr_t * physical_addr, // Physical address to be returned
+		struct pcb_t * proc) {  // Process uses given virtual address
+
+	/* Offset of the virtual address */
+	addr_t offset = get_offset(virtual_addr);
+        offset++; offset--;
+	/* The first layer index */
+	addr_t first_lv = get_first_lv(virtual_addr);
+	/* The second layer index */
+	addr_t second_lv = get_second_lv(virtual_addr);
+	
+	/* Search in the first level */
+	struct trans_table_t * trans_table = NULL;
+	trans_table = get_trans_table(first_lv, proc->page_table);
+	if (trans_table == NULL) {
+		return 0;
+	}
+
+	int i;
+	for (i = 0; i < trans_table->size; i++) {
+		if (trans_table->table[i].v_index == second_lv) {
+			/* DO NOTHING HERE. This mem is obsoleted */
+			return 1;
+		}
+	}
+	return 0;	
+}
+
+addr_t alloc_mem(uint32_t size, struct pcb_t * proc) {
+	pthread_mutex_lock(&mem_lock);
+	addr_t ret_mem = 0;
+	/* DO NOTHING HERE. This mem is obsoleted */
+
+	uint32_t num_pages = (size % PAGE_SIZE) ? size / PAGE_SIZE :
+		size / PAGE_SIZE + 1; // Number of pages we will use
+	int mem_avail = 0; // We could allocate new memory region or not?
+
+	/* First we must check if the amount of free memory in
+	 * virtual address space and physical address space is
+	 * large enough to represent the amount of required 
+	 * memory. If so, set 1 to [mem_avail].
+	 * Hint: check [proc] bit in each page of _mem_stat
+	 * to know whether this page has been used by a process.
+	 * For virtual memory space, check bp (break pointer).
+	 * */
+	
+	if (mem_avail) {
+		/* We could allocate new memory region to the process */
+		ret_mem = proc->bp;
+		proc->bp += num_pages * PAGE_SIZE;
+		/* Update status of physical pages which will be allocated
+		 * to [proc] in _mem_stat. Tasks to do:
+		 * 	- Update [proc], [index], and [next] field
+		 * 	- Add entries to segment table page tables of [proc]
+		 * 	  to ensure accesses to allocated memory slot is
+		 * 	  valid. */
+	}
+	pthread_mutex_unlock(&mem_lock);
+	return ret_mem;
+}
+
+int free_mem(addr_t address, struct pcb_t * proc) {
+	/* DO NOTHING HERE. This mem is obsoleted */
+	return 0;
+}
+
+int read_mem(addr_t address, struct pcb_t * proc, BYTE * data) {
+	addr_t physical_addr;
+	if (translate(address, &physical_addr, proc)) {
+		*data = _ram[physical_addr];
+		return 0;
+	}else{
+		return 1;
+	}
+}
+
+int write_mem(addr_t address, struct pcb_t * proc, BYTE data) {
+	addr_t physical_addr;
+	if (translate(address, &physical_addr, proc)) {
+		_ram[physical_addr] = data;
+		return 0;
+	}else{
+		return 1;
+	}
+}
+
+void dump(void) {
+	int i;
+	for (i = 0; i < NUM_PAGES; i++) {
+		if (_mem_stat[i].proc != 0) {
+			printf("%03d: ", i);
+			printf("%05x-%05x - PID: %02d (idx %03d, nxt: %03d)\n",
+				i << OFFSET_LEN,
+				((i + 1) << OFFSET_LEN) - 1,
+				_mem_stat[i].proc,
+				_mem_stat[i].index,
+				_mem_stat[i].next
+			);
+			int j;
+			for (	j = i << OFFSET_LEN;
+				j < ((i+1) << OFFSET_LEN) - 1;
+				j++) {
+				
+				if (_ram[j] != 0) {
+					printf("\t%05x: %02x\n", j, _ram[j]);
+				}
+					
+			}
+		}
+	}
+}
+
+
diff --git a/ossim_source_code/src/mm-memphy.c b/ossim_source_code/src/mm-memphy.c
new file mode 100644
index 0000000..880a858
--- /dev/null
+++ b/ossim_source_code/src/mm-memphy.c
@@ -0,0 +1,199 @@
+//#ifdef MM_PAGING
+/*
+ * PAGING based Memory Management
+ * Memory physical module mm/mm-memphy.c
+ */
+
+#include "mm.h"
+#include <stdlib.h>
+
+/*
+ *  MEMPHY_mv_csr - move MEMPHY cursor
+ *  @mp: memphy struct
+ *  @offset: offset
+ */
+int MEMPHY_mv_csr(struct memphy_struct *mp, int offset)
+{
+   int numstep = 0;
+
+   mp->cursor = 0;
+   while(numstep < offset && numstep < mp->maxsz){
+     /* Traverse sequentially */
+     mp->cursor = (mp->cursor + 1) % mp->maxsz;
+     numstep++;
+   }
+
+   return 0;
+}
+
+/*
+ *  MEMPHY_seq_read - read MEMPHY device
+ *  @mp: memphy struct
+ *  @addr: address
+ *  @value: obtained value
+ */
+int MEMPHY_seq_read(struct memphy_struct *mp, int addr, BYTE *value)
+{
+   if (mp == NULL)
+     return -1;
+
+   if (!mp->rdmflg)
+     return -1; /* Not compatible mode for sequential read */
+
+   MEMPHY_mv_csr(mp, addr);
+   *value = (BYTE) mp->storage[addr];
+
+   return 0;
+}
+
+/*
+ *  MEMPHY_read read MEMPHY device
+ *  @mp: memphy struct
+ *  @addr: address
+ *  @value: obtained value
+ */
+int MEMPHY_read(struct memphy_struct * mp, int addr, BYTE *value)
+{
+   if (mp == NULL)
+     return -1;
+
+   if (mp->rdmflg)
+      *value = mp->storage[addr];
+   else /* Sequential access device */
+      return MEMPHY_seq_read(mp, addr, value);
+
+   return 0;
+}
+
+/*
+ *  MEMPHY_seq_write - write MEMPHY device
+ *  @mp: memphy struct
+ *  @addr: address
+ *  @data: written data
+ */
+int MEMPHY_seq_write(struct memphy_struct * mp, int addr, BYTE value)
+{
+
+   if (mp == NULL)
+     return -1;
+
+   if (!mp->rdmflg)
+     return -1; /* Not compatible mode for sequential read */
+
+   MEMPHY_mv_csr(mp, addr);
+   mp->storage[addr] = value;
+
+   return 0;
+}
+
+/*
+ *  MEMPHY_write-write MEMPHY device
+ *  @mp: memphy struct
+ *  @addr: address
+ *  @data: written data
+ */
+int MEMPHY_write(struct memphy_struct * mp, int addr, BYTE data)
+{
+   if (mp == NULL)
+     return -1;
+
+   if (mp->rdmflg)
+      mp->storage[addr] = data;
+   else /* Sequential access device */
+      return MEMPHY_seq_write(mp, addr, data);
+
+   return 0;
+}
+
+/*
+ *  MEMPHY_format-format MEMPHY device
+ *  @mp: memphy struct
+ */
+int MEMPHY_format(struct memphy_struct *mp, int pagesz)
+{
+    /* This setting come with fixed constant PAGESZ */
+    int numfp = mp->maxsz / pagesz;
+    struct framephy_struct *newfst, *fst;
+    int iter = 0;
+
+    if (numfp <= 0)
+      return -1;
+
+    /* Init head of free framephy list */ 
+    fst = malloc(sizeof(struct framephy_struct));
+    fst->fpn = iter;
+    mp->free_fp_list = fst;
+
+    /* We have list with first element, fill in the rest num-1 element member*/
+    for (iter = 1; iter < numfp ; iter++)
+    {
+       newfst =  malloc(sizeof(struct framephy_struct));
+       newfst->fpn = iter;
+       newfst->fp_next = NULL;
+       fst->fp_next = newfst;
+       fst = newfst;
+    }
+
+    return 0;
+}
+
+int MEMPHY_get_freefp(struct memphy_struct *mp, int *retfpn)
+{
+   struct framephy_struct *fp = mp->free_fp_list;
+
+   if (fp == NULL)
+     return -1;
+
+   *retfpn = fp->fpn;
+   mp->free_fp_list = fp->fp_next;
+
+   /* MEMPHY is iteratively used up until its exhausted
+    * No garbage collector acting then it not been released
+    */
+   free(fp);
+
+   return 0;
+}
+
+int MEMPHY_dump(struct memphy_struct * mp)
+{
+    /*TODO dump memphy contnt mp->storage 
+     *     for tracing the memory content
+     */
+    
+    return 0;
+}
+
+int MEMPHY_put_freefp(struct memphy_struct *mp, int fpn)
+{
+   struct framephy_struct *fp = mp->free_fp_list;
+   struct framephy_struct *newnode = malloc(sizeof(struct framephy_struct));
+
+   /* Create new node with value fpn */
+   newnode->fpn = fpn;
+   newnode->fp_next = fp;
+   mp->free_fp_list = newnode;
+
+   return 0;
+}
+
+
+/*
+ *  Init MEMPHY struct
+ */
+int init_memphy(struct memphy_struct *mp, int max_size, int randomflg)
+{
+   mp->storage = (BYTE *)malloc(max_size*sizeof(BYTE));
+   mp->maxsz = max_size;
+
+   MEMPHY_format(mp,PAGING_PAGESZ);
+
+   mp->rdmflg = (randomflg != 0)?1:0;
+
+   if (!mp->rdmflg )   /* Not Ramdom acess device, then it serial device*/
+      mp->cursor = 0;
+
+   return 0;
+}
+
+//#endif
diff --git a/ossim_source_code/src/mm-vm.c b/ossim_source_code/src/mm-vm.c
new file mode 100644
index 0000000..c262322
--- /dev/null
+++ b/ossim_source_code/src/mm-vm.c
@@ -0,0 +1,649 @@
+//#ifdef MM_PAGING
+/*
+ * PAGING based Memory Management
+ * Virtual memory module mm/mm-vm.c
+ */
+
+#include "string.h"
+#include "mm.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+/*enlist_vm_freerg_list - add new rg to freerg_list
+ *@mm: memory region
+ *@rg_elmt: new region
+ *
+ */
+int enlist_vm_freerg_list(struct mm_struct *mm, struct vm_rg_struct rg_elmt)
+{
+    struct vm_rg_struct *new_node;
+    struct vm_rg_struct *head = mm->mmap->vm_freerg_list;
+
+    // Check for invalid region
+    if (rg_elmt.rg_start >= rg_elmt.rg_end)
+        return -1;
+
+    // Dynamically allocate memory for the new region
+    new_node = (struct vm_rg_struct *)malloc(sizeof(struct vm_rg_struct));
+    if (!new_node)
+        return -1; // Allocation failed
+
+    // Copy the data into the new node
+    *new_node = rg_elmt;
+    new_node->rg_next = head;
+
+    // Update the list head
+    mm->mmap->vm_freerg_list = new_node;
+
+    return 0;
+}
+
+
+/*get_vma_by_num - get vm area by numID
+ *@mm: memory region
+ *@vmaid: ID vm area to alloc memory region
+ *
+ */
+//get địa chỉ ô vma
+struct vm_area_struct *get_vma_by_num(struct mm_struct *mm, int vmaid)
+{
+  struct vm_area_struct *pvma= mm->mmap;
+
+  if(mm->mmap == NULL)
+    return NULL;
+
+  int vmait = 0;
+  
+  while (vmait < vmaid)
+  {
+    if(pvma == NULL)
+	  return NULL;
+
+    vmait++;
+    pvma = pvma->vm_next;
+  }
+
+  return pvma;
+}
+
+/*get_symrg_byid - get mem region by region ID
+ *@mm: memory region
+ *@rgid: region ID act as symbol index of variable
+ *
+ */
+struct vm_rg_struct *get_symrg_byid(struct mm_struct *mm, int rgid)
+{
+  if(rgid < 0 || rgid > PAGING_MAX_SYMTBL_SZ)
+    return NULL;
+
+  return &mm->symrgtbl[rgid];
+}
+
+/*__alloc - allocate a region memory
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@rgid: memory region ID (used to identify variable in symbole table)
+ *@size: allocated size 
+ *@alloc_addr: address of allocated memory region
+ *
+ */
+int __alloc(struct pcb_t *caller, int vmaid, int rgid, int size, int *alloc_addr)
+{
+  /*Allocate at the toproof */
+  struct vm_rg_struct rgnode;
+
+  /* TODO: commit the vmaid */
+  rgnode.vmaid = vmaid;
+
+  if (get_free_vmrg_area(caller, vmaid, size, &rgnode) == 0)
+  {
+    //symrgtbl là vm_rg_struct
+    caller->mm->symrgtbl[rgid].rg_start = rgnode.rg_start;
+    caller->mm->symrgtbl[rgid].rg_end = rgnode.rg_end;
+
+    caller->mm->symrgtbl[rgid].vmaid = rgnode.vmaid;
+
+    *alloc_addr = rgnode.rg_start;
+
+    return 0;
+  }
+
+  /* TODO: get_free_vmrg_area FAILED handle the region management (Fig.6)*/
+  if (get_free_vmrg_area(caller, vmaid, size, &rgnode) == -1 ){return -1;}
+  /* TODO retrive current vma if needed, current comment out due to compiler redundant warning*/
+  /*Attempt to increate limit to get space */
+
+  struct vm_area_struct *cur_vma = get_vma_by_num(caller->mm, vmaid);
+  int inc_sz = PAGING_PAGE_ALIGNSZ(size);
+  int inc_limit_ret;
+
+  /* TODO retrive old_sbrk if needed, current comment out due to compiler redundant warning*/
+  int old_sbrk = cur_vma->sbrk;
+
+  /* TODO INCREASE THE LIMIT
+   * inc_vma_limit(caller, vmaid, inc_sz)
+   */
+  if (inc_vma_limit(caller, vmaid, inc_sz, &inc_limit_ret) < 0) return -1;
+
+    cur_vma->sbrk += inc_sz;
+  /* TODO: commit the limit increment */
+    if ( old_sbrk + size > cur_vma -> vm_end )
+ {
+ if ( inc_vma_limit ( caller , vmaid , inc_sz, &inc_limit_ret ) < 0)
+ {
+            struct framephy_struct * frm_lst = NULL ;
+            struct vm_rg_struct * ret_rg = malloc ( sizeof ( struct vm_rg_struct ) );
+            int pages = ( inc_sz / PAGING_PAGESZ );
+            ret_rg -> rg_start = ret_rg -> rg_end = old_sbrk ;
+            ret_rg -> rg_next = NULL ;
+            alloc_pages_range ( caller , pages , & frm_lst );
+            vmap_page_range ( caller , old_sbrk , pages , frm_lst , ret_rg );
+            caller ->mm -> symrgtbl [ rgid ]. rg_start = ret_rg -> rg_start ;
+            caller ->mm -> symrgtbl [ rgid ]. rg_end = ret_rg -> rg_end ;
+            cur_vma -> sbrk += ret_rg -> rg_end - ret_rg -> rg_start ;
+            return 0;
+ }
+ }
+
+ /* Successful increase limit */
+ caller ->mm -> symrgtbl [ rgid ]. rg_start = old_sbrk ;
+ caller ->mm -> symrgtbl [ rgid ]. rg_end = old_sbrk + size ;
+  /* TODO: commit the allocation address 
+  // *alloc_addr = ...
+  */
+ *alloc_addr = rgnode.rg_start;
+
+  return 0;
+}
+
+/*__free - remove a region memory
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@rgid: memory region ID (used to identify variable in symbole table)
+ *@size: allocated size 
+ *
+ */
+int __free(struct pcb_t *caller, int rgid)
+{
+  struct vm_rg_struct rgnode;
+
+  // Dummy initialization for avoding compiler dummay warning
+  // in incompleted TODO code rgnode will overwrite through implementing
+  // the manipulation of rgid later
+  rgnode.vmaid = 0;  //dummy initialization
+  rgnode.vmaid = 1;  //dummy initialization
+
+  if(rgid < 0 || rgid > PAGING_MAX_SYMTBL_SZ)
+    return -1;
+
+  /* TODO: Manage the collect freed region to freerg_list */
+  struct vm_rg_struct *sym_rg = &caller->mm->symrgtbl[rgid];
+  rgnode.rg_start = sym_rg->rg_start;
+  rgnode.rg_end = sym_rg->rg_end;
+  rgnode.vmaid = sym_rg->vmaid;
+  
+  /*enlist the obsoleted memory region */
+  enlist_vm_freerg_list(caller->mm, rgnode);
+
+  return 0;
+}
+
+/*pgalloc - PAGING-based allocate a region memory
+ *@proc:  Process executing the instruction
+ *@size: allocated size 
+ *@reg_index: memory region ID (used to identify variable in symbole table)
+ */
+int pgalloc(struct pcb_t *proc, uint32_t size, uint32_t reg_index)
+{
+  int addr;
+
+  /* By default using vmaid = 0 */
+  return __alloc(proc, 0, reg_index, size, &addr);
+}
+
+/*pgmalloc - PAGING-based allocate a region memory
+ *@proc:  Process executing the instruction
+ *@size: allocated size 
+ *@reg_index: memory region ID (used to identify vaiable in symbole table)
+ */
+int pgmalloc(struct pcb_t *proc, uint32_t size, uint32_t reg_index)
+{
+  int addr;
+
+  /* By default using vmaid = 1 */
+  return __alloc(proc, 1, reg_index, size, &addr);
+}
+
+/*pgfree - PAGING-based free a region memory
+ *@proc: Process executing the instruction
+ *@size: allocated size 
+ *@reg_index: memory region ID (used to identify variable in symbole table)
+ */
+
+int pgfree_data(struct pcb_t *proc, uint32_t reg_index)
+{
+   return __free(proc, reg_index);
+}
+
+/*pg_getpage - get the page in ram
+ *@mm: memory region
+ *@pagenum: PGN
+ *@framenum: return FPN
+ *@caller: caller
+ *
+ */
+int pg_getpage(struct mm_struct *mm, int pgn, int *fpn, struct pcb_t *caller)
+{
+    uint32_t pte = mm->pgd[pgn];
+
+    if (!PAGING_PTE_PAGE_PRESENT(pte))
+    { 
+        // Page không tồn tại, cần đưa vào bộ nhớ
+        int vicpgn, swpfpn, vicfpn;
+        uint32_t vicpte;
+
+        int tgtfpn = PAGING_PTE_SWP(pte); // Frame mục tiêu trong swap
+
+        // Tìm victim page
+        if (find_victim_page(caller->mm, &vicpgn) < 0)
+            return -1;
+
+        vicpte = caller->mm->pgd[vicpgn];
+        vicfpn = PAGING_OFFST(vicpte);
+
+        // Lấy free frame từ MEMSWP
+        if (MEMPHY_get_freefp(caller->active_mswp, &swpfpn) < 0)
+        {
+            struct memphy_struct **mswpit = caller->mswp;
+            for (int i = 0; i < PAGING_MAX_MMSWP; i++)
+            {
+                struct memphy_struct *tmp_swp = mswpit[i];
+                if (MEMPHY_get_freefp(tmp_swp, &swpfpn) == 0)
+                {
+                    __swap_cp_page(caller->mram, vicfpn, tmp_swp, swpfpn);
+                    caller->active_mswp = tmp_swp;
+                    break;
+                }
+            }
+        }
+        else
+        {
+            __swap_cp_page(caller->mram, vicfpn, caller->active_mswp, swpfpn);
+        }
+
+        // Swap frame từ MEMRAM sang MEMSWP và ngược lại
+        __swap_cp_page(caller->active_mswp, tgtfpn, caller->mram, vicfpn);
+
+        // Cập nhật page table
+        MEMPHY_put_freefp(caller->active_mswp, tgtfpn);
+        // swptype = 1
+        pte_set_swap(&caller->mm->pgd[vicpgn], 1, swpfpn);
+
+        // Đánh dấu trạng thái online của page mục tiêu
+        pte_set_fpn(&caller->mm->pgd[pgn], vicfpn);
+        pte = caller->mm->pgd[pgn];
+
+
+
+    *fpn = PAGING_OFFST(pte);
+    return 0;
+}
+}
+
+    /* Do swap frame from MEMRAM to MEMSWP and vice versa*/
+    /* Copy victim frame to swap */
+    //__swap_cp_page();
+    /* Copy target frame from swap to mem */
+    //__swap_cp_page();
+
+    /* Update page table */
+    //pte_set_swap() &mm->pgd;
+
+    /* Update its online status of the target page */
+    //pte_set_fpn() & mm->pgd[pgn];
+  //   pte_set_fpn(&pte, tgtfpn);
+
+  //   enlist_pgn_node(&caller->mm->fifo_pgn,pgn);
+  // }
+
+  // *fpn = PAGING_PTE_FPN(pte);
+
+  // return 0;
+
+
+/*pg_getval - read value at given offset
+ *@mm: memory region
+ *@addr: virtual address to acess 
+ *@value: value
+ *
+ */
+int pg_getval(struct mm_struct *mm, int addr, BYTE *data, struct pcb_t *caller)
+{
+  int pgn = PAGING_PGN(addr);
+  int off = PAGING_OFFST(addr);
+  int fpn;
+
+  /* Get the page to MEMRAM, swap from MEMSWAP if needed */
+  if(pg_getpage(mm, pgn, &fpn, caller) != 0) 
+    return -1; /* invalid page access */
+
+  int phyaddr = (fpn << PAGING_ADDR_FPN_LOBIT) + off;
+
+  MEMPHY_read(caller->mram,phyaddr, data);
+
+  return 0;
+}
+
+/*pg_setval - write value to given offset
+ *@mm: memory region
+ *@addr: virtual address to acess 
+ *@value: value
+ *
+ */
+int pg_setval(struct mm_struct *mm, int addr, BYTE value, struct pcb_t *caller)
+{
+  int pgn = PAGING_PGN(addr);
+  int off = PAGING_OFFST(addr);
+  int fpn;
+
+  /* Get the page to MEMRAM, swap from MEMSWAP if needed */
+  if(pg_getpage(mm, pgn, &fpn, caller) != 0) 
+    return -1; /* invalid page access */
+
+  int phyaddr = (fpn << PAGING_ADDR_FPN_LOBIT) + off;
+
+  MEMPHY_write(caller->mram,phyaddr, value);
+
+   return 0;
+}
+
+/*__read - read value in region memory
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@offset: offset to acess in memory region 
+ *@rgid: memory region ID (used to identify variable in symbole table)
+ *@size: allocated size 
+ *
+ */
+int __read(struct pcb_t *caller, int rgid, int offset, BYTE *data)
+{
+  struct vm_rg_struct *currg = get_symrg_byid(caller->mm, rgid);
+  int vmaid = currg->vmaid;
+
+  struct vm_area_struct *cur_vma = get_vma_by_num(caller->mm, vmaid);
+
+  if(currg == NULL || cur_vma == NULL) /* Invalid memory identify */
+	  return -1;
+
+  pg_getval(caller->mm, currg->rg_start + offset, data, caller);
+
+  return 0;
+}
+
+
+/*pgwrite - PAGING-based read a region memory */
+int pgread(
+		struct pcb_t * proc, // Process executing the instruction
+		uint32_t source, // Index of source register
+		uint32_t offset, // Source address = [source] + [offset]
+		uint32_t destination) 
+{
+  BYTE data;
+  int val = __read(proc, source, offset, &data);
+
+  destination = (uint32_t) data;
+#ifdef IODUMP
+  printf("read region=%d offset=%d value=%d\n", source, offset, data);
+#ifdef PAGETBL_DUMP
+  print_pgtbl(proc, 0, -1); //print max TBL
+#endif
+  MEMPHY_dump(proc->mram);
+#endif
+
+  return val;
+}
+
+/*__write - write a region memory
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@offset: offset to acess in memory region 
+ *@rgid: memory region ID (used to identify variable in symbole table)
+ *@size: allocated size 
+ *
+ */
+int __write(struct pcb_t *caller, int rgid, int offset, BYTE value)
+{
+  struct vm_rg_struct *currg = get_symrg_byid(caller->mm, rgid);
+  int vmaid = currg->vmaid;
+
+  struct vm_area_struct *cur_vma = get_vma_by_num(caller->mm, vmaid);
+  
+  if(currg == NULL || cur_vma == NULL) /* Invalid memory identify */
+	  return -1;
+
+  pg_setval(caller->mm, currg->rg_start + offset, value, caller);
+
+  return 0;
+}
+
+/*pgwrite - PAGING-based write a region memory */
+int pgwrite(
+		struct pcb_t * proc, // Process executing the instruction
+		BYTE data, // Data to be wrttien into memory
+		uint32_t destination, // Index of destination register
+		uint32_t offset)
+{
+#ifdef IODUMP
+  printf("write region=%d offset=%d value=%d\n", destination, offset, data);
+#ifdef PAGETBL_DUMP
+  print_pgtbl(proc, 0, -1); //print max TBL
+#endif
+  MEMPHY_dump(proc->mram);
+#endif
+
+  return __write(proc, destination, offset, data);
+}
+
+
+/*free_pcb_memphy - collect all memphy of pcb
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@incpgnum: number of page
+ */
+int free_pcb_memph(struct pcb_t *caller)
+{
+  int pagenum, fpn;
+  uint32_t pte;
+
+
+  for(pagenum = 0; pagenum < PAGING_MAX_PGN; pagenum++)
+  {
+    pte= caller->mm->pgd[pagenum];
+
+    if (!PAGING_PTE_PAGE_PRESENT(pte))
+    {
+      fpn = PAGING_PTE_FPN(pte);
+      MEMPHY_put_freefp(caller->mram, fpn);
+    } else {
+      fpn = PAGING_PTE_SWP(pte);
+      MEMPHY_put_freefp(caller->active_mswp, fpn);    
+    }
+  }
+
+  return 0;
+}
+
+/*get_vm_area_node - get vm area for a number of pages
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@incpgnum: number of page
+ *@vmastart: vma end
+ *@vmaend: vma end
+ *
+ */
+struct vm_rg_struct* get_vm_area_node_at_brk(struct pcb_t *caller, int vmaid, int size, int alignedsz)
+{
+  struct vm_rg_struct * newrg = malloc(sizeof(struct vm_rg_struct));;
+  /* TODO retrive current vma to obtain newrg, current comment out due to compiler redundant warning*/
+  struct vm_area_struct *cur_vma = get_vma_by_num(caller->mm, vmaid);
+  
+  /* TODO: update the newrg boundary
+  // newrg->rg_start = ...
+  // newrg->rg_end = ...
+  */
+
+ newrg->rg_start = cur_vma -> sbrk;
+
+ if ( (cur_vma ->sbrk + alignedsz) > cur_vma -> vm_end ) return newrg = cur_vma -> sbrk; 
+cur_vma ->sbrk = cur_vma->sbrk + alignedsz;
+
+ newrg->rg_end = cur_vma -> sbrk;
+ 
+return newrg;
+}
+
+/*validate_overlap_vm_area
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@vmastart: vma end
+ *@vmaend: vma end
+ *
+ */
+int validate_overlap_vm_area(struct pcb_t *caller, int vmaid, int vmastart, int vmaend)
+{
+  struct vm_area_struct *vma = caller->mm->mmap;
+
+  /* TODO validate the planned memory area is not overlapped */
+  while(vma != NULL)
+  {
+    
+      if ((vmastart >= vma->vm_start && vmastart < vma->vm_end) || (vmastart <= vma->vm_start && vmaend >= vma->vm_end))
+      {
+        return -1; 
+      }
+      vma = vma->vm_next;
+  }
+  return 0;
+}
+
+/*inc_vma_limit - increase vm area limits to reserve space for new variable
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@inc_sz: increment size 
+ *@inc_limit_ret: increment limit return
+ *
+ */
+int inc_vma_limit(struct pcb_t *caller, int vmaid, int inc_sz, int* inc_limit_ret)
+{
+  struct vm_rg_struct * newrg = malloc(sizeof(struct vm_rg_struct));
+  int inc_amt = PAGING_PAGE_ALIGNSZ(inc_sz);
+  int incnumpage =  inc_amt / PAGING_PAGESZ;
+  struct vm_rg_struct *area = get_vm_area_node_at_brk(caller, vmaid, inc_sz, inc_amt);
+  struct vm_area_struct *cur_vma = get_vma_by_num(caller->mm, vmaid);
+ 
+  int old_end = cur_vma->vm_end;
+
+  /*Validate overlap of obtained region */
+  if (validate_overlap_vm_area(caller, vmaid, area->rg_start, area->rg_end) < 0)
+    return -1; /*Overlap and failed allocation */
+
+  /* TODO: Obtain the new vm area based on vmaid */
+  cur_vma->sbrk = area -> rg_start;
+
+
+  if (vm_map_ram(caller, area->rg_start, area->rg_end, 
+                    old_end, incnumpage , newrg) < 0)
+    return -1; /* Map the memory to MEMRAM */
+  inc_limit_ret = cur_vma->vm_end + inc_sz;
+  return 0;
+
+}
+
+/*find_victim_page - find victim page
+ *@caller: caller
+ *@pgn: return page number
+ *
+ */
+int find_victim_page(struct mm_struct *mm, int *retpgn) 
+{
+  struct pgn_t *pg = mm->fifo_pgn;
+  
+  /* TODO: Implement the theorical mechanism to find the victim page */
+  if (pg == NULL) return -1;
+
+  *retpgn = pg->pgn;
+
+  mm->fifo_pgn = pg->pg_next;
+
+  free(pg);
+
+  return 0;
+}
+
+/*get_free_vmrg_area - get a free vm region
+ *@caller: caller
+ *@vmaid: ID vm area to alloc memory region
+ *@size: allocated size 
+ *
+ */
+int get_free_vmrg_area(struct pcb_t *caller, int vmaid, int size, struct vm_rg_struct *newrg)
+{
+  struct vm_area_struct *cur_vma = get_vma_by_num(caller->mm, vmaid);
+
+  struct vm_rg_struct *rgit = cur_vma->vm_freerg_list;
+
+  if (rgit == NULL)
+    return -1;
+
+  /* Probe unintialized newrg */
+  newrg->rg_start = newrg->rg_end = -1;
+
+  /* Traverse on list of free vm region to find a fit space */
+  //check điều kiện bịp
+  while (rgit != NULL && rgit->vmaid == vmaid)
+  {
+    if (rgit->rg_start + size <= rgit->rg_end)
+    { /* Current region has enough space */
+      newrg->rg_start = rgit->rg_start;
+      newrg->rg_end = rgit->rg_start + size;
+
+      /* Update left space in chosen region */
+      if (rgit->rg_start + size < rgit->rg_end)
+      {
+        rgit->rg_start = rgit->rg_start + size;
+      }
+      else
+      { /*Use up all space, remove current node */
+        /*Clone next rg node */
+        struct vm_rg_struct *nextrg = rgit->rg_next;
+
+        /*Cloning */
+        if (nextrg != NULL)
+        {
+          rgit->rg_start = nextrg->rg_start;
+          rgit->rg_end = nextrg->rg_end;
+
+          rgit->rg_next = nextrg->rg_next;
+
+          free(nextrg);
+        }
+        else
+        { /*End of free list */
+          rgit->rg_start = rgit->rg_end;	//dummy, size 0 region
+          rgit->rg_next = NULL;
+        }
+      }
+    }
+    else
+    {
+      rgit = rgit->rg_next;	// Traverse next rg
+    }
+  }
+
+ if(newrg->rg_start == -1) // new region not found
+   return -1;
+
+ return 0;
+}
+
+//#endif
diff --git a/ossim_source_code/src/mm.c b/ossim_source_code/src/mm.c
new file mode 100644
index 0000000..5071151
--- /dev/null
+++ b/ossim_source_code/src/mm.c
@@ -0,0 +1,458 @@
+//#ifdef MM_PAGING
+/*
+ * PAGING based Memory Management
+ * Memory management unit mm/mm.c
+ */
+
+#include "mm.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+/* 
+ * init_pte - Initialize PTE entry
+ */
+int init_pte(uint32_t *pte,
+             int pre,    // present
+             int fpn,    // FPN
+             int drt,    // dirty
+             int swp,    // swap
+             int swptyp, // swap type
+             int swpoff) //swap offset
+{
+  if (pre != 0) {
+    if (swp == 0) { // Non swap ~ page online
+      if (fpn == 0) 
+        return -1; // Invalid setting
+
+      /* Valid setting with FPN */
+      SETBIT(*pte, PAGING_PTE_PRESENT_MASK);
+      CLRBIT(*pte, PAGING_PTE_SWAPPED_MASK);
+      CLRBIT(*pte, PAGING_PTE_DIRTY_MASK);
+
+      SETVAL(*pte, fpn, PAGING_PTE_FPN_MASK, PAGING_PTE_FPN_LOBIT); 
+    } else { // page swapped
+      SETBIT(*pte, PAGING_PTE_PRESENT_MASK);
+      SETBIT(*pte, PAGING_PTE_SWAPPED_MASK);
+      CLRBIT(*pte, PAGING_PTE_DIRTY_MASK);
+
+      SETVAL(*pte, swptyp, PAGING_PTE_SWPTYP_MASK, PAGING_PTE_SWPTYP_LOBIT); 
+      SETVAL(*pte, swpoff, PAGING_PTE_SWPOFF_MASK, PAGING_PTE_SWPOFF_LOBIT);
+    }
+  }
+
+  return 0;   
+}
+
+/* 
+ * pte_set_swap - Set PTE entry for swapped page
+ * @pte    : target page table entry (PTE)
+ * @swptyp : swap type
+ * @swpoff : swap offset
+ */
+int pte_set_swap(uint32_t *pte, int swptyp, int swpoff)
+{
+  SETBIT(*pte, PAGING_PTE_PRESENT_MASK);
+  SETBIT(*pte, PAGING_PTE_SWAPPED_MASK);
+
+  SETVAL(*pte, swptyp, PAGING_PTE_SWPTYP_MASK, PAGING_PTE_SWPTYP_LOBIT);
+  SETVAL(*pte, swpoff, PAGING_PTE_SWPOFF_MASK, PAGING_PTE_SWPOFF_LOBIT);
+
+  return 0;
+}
+
+/* 
+ * pte_set_swap - Set PTE entry for on-line page
+ * @pte   : target page table entry (PTE)
+ * @fpn   : frame page number (FPN)
+ */
+int pte_set_fpn(uint32_t *pte, int fpn)
+{
+  SETBIT(*pte, PAGING_PTE_PRESENT_MASK);
+  CLRBIT(*pte, PAGING_PTE_SWAPPED_MASK);
+
+  SETVAL(*pte, fpn, PAGING_PTE_FPN_MASK, PAGING_PTE_FPN_LOBIT); 
+
+  return 0;
+}
+
+
+/* 
+ * vmap_page_range - map a range of page at aligned address
+ */
+int vmap_page_range(struct pcb_t *caller, // process call
+                                int addr, // start address which is aligned to pagesz
+                               int pgnum, // num of mapping page
+           struct framephy_struct *frames,// list of the mapped frames
+              struct vm_rg_struct *ret_rg)// return mapped region, the real mapped fp
+{                                         // no guarantee all given pages are mapped
+  //uint32_t * pte = malloc(sizeof(uint32_t));
+  struct framephy_struct *fpit = malloc(sizeof(struct framephy_struct));
+  //int  fpn;
+  int pgit = 0;
+  int pgn = PAGING_PGN(addr);
+
+  /* TODO: update the rg_end and rg_start of ret_rg 
+  //ret_rg->rg_end =  ....
+  //ret_rg->rg_start = ...
+  //ret_rg->vmaid = ...
+  */
+ ret_rg -> rg_end = ret_rg -> rg_start = addr ; 
+
+  fpit->fp_next = frames;
+
+  /* TODO map range of frame to address space 
+   *      in page table pgd in caller->mm
+   */
+
+   /* Tracking for later page replacement activities (if needed)
+    * Enqueue new usage page */
+   while ( pgit < pgnum )
+ {
+      if ( fpit == NULL )
+          {
+          break ;
+          }
+    pgn = PAGING_PGN ( addr + pgnum * PAGING_PAGESZ );
+    pte_set_fpn (&( caller ->mm -> pgd [ pgn ]) , fpit -> fpn ) ;
+    enlist_pgn_node (& caller -> mm -> fifo_pgn , pgn + pgit ) ;
+    fpit = fpit -> fp_next ;
+ }
+ ret_rg -> rg_end += pgit * PAGING_PAGESZ ;
+ return 0;
+  
+}
+
+/* 
+ * alloc_pages_range - allocate req_pgnum of frame in ram
+ * @caller    : caller
+ * @req_pgnum : request page num
+ * @frm_lst   : frame list
+ */
+
+int alloc_pages_range(struct pcb_t *caller, int req_pgnum, struct framephy_struct** frm_lst)
+{
+    int pgit, fpn;
+    struct framephy_struct *newfp_str;
+
+    for (pgit = 0; pgit < req_pgnum; pgit++)
+    {
+        if (MEMPHY_get_freefp(caller->mram, &fpn) == 0)
+        {
+            newfp_str = malloc(sizeof(struct framephy_struct));
+            newfp_str->fpn = fpn;
+            newfp_str->owner = caller->mm;
+            newfp_str->fp_next = NULL;
+
+            if (!*frm_lst)
+            {
+                *frm_lst = newfp_str;
+            }
+            else
+            {
+                newfp_str->fp_next = *frm_lst;
+                *frm_lst = newfp_str;
+            }
+
+            struct framephy_struct *temp = malloc(sizeof(struct framephy_struct));
+            *temp = *newfp_str;
+            temp->fp_next = caller->mram->used_fp_list;
+            caller->mram->used_fp_list = temp;
+        }
+        else
+        {
+            // ERROR CODE of obtaining some but not enough frames
+            int vicfpn, vicpgn, swpfpn;
+            uint32_t vicpte;
+
+            if (find_victim_page(caller->mm, &vicpgn) < 0)
+            {
+                return -1;
+            }
+
+            vicpte = caller->mm->pgd[vicpgn];
+            vicfpn = PAGING_OFFST(vicpte);
+
+            newfp_str = malloc(sizeof(struct framephy_struct));
+            newfp_str->fpn = vicfpn;
+            newfp_str->owner = caller->mm;
+            newfp_str->fp_next = NULL;
+
+            if (!*frm_lst)
+            {
+                *frm_lst = newfp_str;
+            }
+            else
+            {
+                newfp_str->fp_next = *frm_lst;
+                *frm_lst = newfp_str;
+            }
+
+            int i;
+            if (MEMPHY_get_freefp(caller->active_mswp, &swpfpn) == 0)
+            {
+                __swap_cp_page(caller->mram, vicfpn, caller->active_mswp, swpfpn);
+                struct memphy_struct *mswp = *caller->mswp;
+                for (i = 0; i < PAGING_MAX_MMSWP; i++)
+                {
+                    if (mswp + i == caller->active_mswp) break;
+                }
+            }
+            else
+            {
+                struct memphy_struct *mswp = *caller->mswp;
+                swpfpn = -1;
+                for (i = 0; i < PAGING_MAX_MMSWP; i++)
+                {
+                    if (MEMPHY_get_freefp(mswp + i, &swpfpn) == 0)
+                    {
+                        __swap_cp_page(caller->mram, vicfpn, mswp + i, swpfpn);
+                        break;
+                    }
+                }
+            }
+
+            if (swpfpn == -1)
+                return -3000;
+
+            pte_set_swap(&caller->mm->pgd[vicpgn], i, swpfpn);
+        }
+    }
+
+    return 0;
+}
+
+
+
+/* 
+ * vm_map_ram - do the mapping all vm are to ram storage device
+ * @caller    : caller
+ * @astart    : vm area start
+ * @aend      : vm area end
+ * @mapstart  : start mapping point
+ * @incpgnum  : number of mapped page
+ * @ret_rg    : returned region
+ */
+int vm_map_ram(struct pcb_t *caller, int astart, int aend, int mapstart, int incpgnum, struct vm_rg_struct *ret_rg)
+{
+  struct framephy_struct *frm_lst = NULL;
+  int ret_alloc;
+
+  /*@bksysnet: author provides a feasible solution of getting frames
+   *FATAL logic in here, wrong behaviour if we have not enough page
+   *i.e. we request 1000 frames meanwhile our RAM has size of 3 frames
+   *Don't try to perform that case in this simple work, it will result
+   *in endless procedure of swap-off to get frame and we have not provide 
+   *duplicate control mechanism, keep it simple
+   */
+  ret_alloc = alloc_pages_range(caller, incpgnum, &frm_lst);
+
+  if (ret_alloc < 0 && ret_alloc != -3000)
+    return -1;
+
+  /* Out of memory */
+  if (ret_alloc == -3000) 
+  {
+#ifdef MMDBG
+     printf("OOM: vm_map_ram out of memory \n");
+#endif
+     return -1;
+  }
+
+  /* it leaves the case of memory is enough but half in ram, half in swap
+   * do the swaping all to swapper to get the all in ram */
+  vmap_page_range(caller, mapstart, incpgnum, frm_lst, ret_rg);
+
+  return 0;
+}
+
+/* Swap copy content page from source frame to destination frame 
+ * @mpsrc  : source memphy
+ * @srcfpn : source physical page number (FPN)
+ * @mpdst  : destination memphy
+ * @dstfpn : destination physical page number (FPN)
+ **/
+int __swap_cp_page(struct memphy_struct *mpsrc, int srcfpn,
+                struct memphy_struct *mpdst, int dstfpn) 
+{
+  int cellidx;
+  int addrsrc,addrdst;
+  for(cellidx = 0; cellidx < PAGING_PAGESZ; cellidx++)
+  {
+    addrsrc = srcfpn * PAGING_PAGESZ + cellidx;
+    addrdst = dstfpn * PAGING_PAGESZ + cellidx;
+
+    BYTE data;
+    MEMPHY_read(mpsrc, addrsrc, &data);
+    MEMPHY_write(mpdst, addrdst, data);
+  }
+
+  return 0;
+}
+
+/*
+ *Initialize a empty Memory Management instance
+ * @mm:     self mm
+ * @caller: mm owner
+ */
+int init_mm(struct mm_struct *mm, struct pcb_t *caller)
+{
+    struct vm_area_struct *vma0 = malloc(sizeof(struct vm_area_struct));
+    struct vm_area_struct *vma1 = malloc(sizeof(struct vm_area_struct));
+
+    mm->pgd = malloc(PAGING_MAX_PGN * sizeof(uint32_t));
+
+    /* By default the owner comes with at least one vma for DATA */
+    vma0->vm_id = 0;
+    vma0->vm_start = 0;
+    vma0->vm_end = vma0->vm_start;
+    vma0->sbrk = vma0->vm_start;
+
+    struct vm_rg_struct *first_rg = init_vm_rg(vma0->vm_start, vma0->vm_end, 0);
+    enlist_vm_rg_node(&vma0->vm_freerg_list, first_rg);
+
+    /* Update vma0 next */
+    vma0->vm_next = vma1;  // Assuming vma1 is the next VM area
+
+    /* Update one vma for HEAP */
+    vma1->vm_id = 1;  // Assuming ID for heap
+   // vma1->vm_start = HEAP_START;  // Define an appropriate start address for the heap
+    //vma1->vm_end = HEAP_END;      // Define the end address for the heap
+    vma1->sbrk = vma1->vm_start;
+
+    struct vm_rg_struct *first_rg_heap = init_vm_rg(vma1->vm_start, vma1->vm_end, 0);
+    enlist_vm_rg_node(&vma1->vm_freerg_list, first_rg_heap);
+
+    /* Set next for vma1 */
+    vma1->vm_next = NULL;  // Assuming it's the last one in the list for now
+
+    /* Point vma owner backward */
+    vma0->vm_mm = mm;
+    vma1->vm_mm = mm;
+
+    /* Update mmap */
+    mm->mmap = vma0;  // Start the mmap list with vma0
+
+    return 0;
+}
+
+
+struct vm_rg_struct* init_vm_rg(int rg_start, int rg_end, int vmaid)
+{
+  struct vm_rg_struct *rgnode = malloc(sizeof(struct vm_rg_struct));
+
+  rgnode->rg_start = rg_start;
+  rgnode->rg_end = rg_end;
+  rgnode->vmaid = vmaid;
+  rgnode->rg_next = NULL;
+
+  return rgnode;
+}
+
+int enlist_vm_rg_node(struct vm_rg_struct **rglist, struct vm_rg_struct* rgnode)
+{
+  rgnode->rg_next = *rglist;
+  *rglist = rgnode;
+
+  return 0;
+}
+
+int enlist_pgn_node(struct pgn_t **plist, int pgn)
+{
+  struct pgn_t* pnode = malloc(sizeof(struct pgn_t));
+
+  pnode->pgn = pgn;
+  pnode->pg_next = *plist;
+  *plist = pnode;
+
+  return 0;
+}
+
+int print_list_fp(struct framephy_struct *ifp)
+{
+   struct framephy_struct *fp = ifp;
+ 
+   printf("print_list_fp: ");
+   if (fp == NULL) {printf("NULL list\n"); return -1;}
+   printf("\n");
+   while (fp != NULL )
+   {
+       printf("fp[%d]\n",fp->fpn);
+       fp = fp->fp_next;
+   }
+   printf("\n");
+   return 0;
+}
+
+int print_list_rg(struct vm_rg_struct *irg)
+{
+   struct vm_rg_struct *rg = irg;
+ 
+   printf("print_list_rg: ");
+   if (rg == NULL) {printf("NULL list\n"); return -1;}
+   printf("\n");
+   while (rg != NULL)
+   {
+       printf("rg[%ld->%ld<at>vma=%d]\n",rg->rg_start, rg->rg_end, rg->vmaid);
+       rg = rg->rg_next;
+   }
+   printf("\n");
+   return 0;
+}
+
+int print_list_vma(struct vm_area_struct *ivma)
+{
+   struct vm_area_struct *vma = ivma;
+ 
+   printf("print_list_vma: ");
+   if (vma == NULL) {printf("NULL list\n"); return -1;}
+   printf("\n");
+   while (vma != NULL )
+   {
+       printf("va[%ld->%ld]\n",vma->vm_start, vma->vm_end);
+       vma = vma->vm_next;
+   }
+   printf("\n");
+   return 0;
+}
+
+int print_list_pgn(struct pgn_t *ip)
+{
+   printf("print_list_pgn: ");
+   if (ip == NULL) {printf("NULL list\n"); return -1;}
+   printf("\n");
+   while (ip != NULL )
+   {
+       printf("va[%d]-\n",ip->pgn);
+       ip = ip->pg_next;
+   }
+   printf("n");
+   return 0;
+}
+
+int print_pgtbl(struct pcb_t *caller, uint32_t start, uint32_t end)
+{
+  int pgn_start,pgn_end;
+  int pgit;
+
+  if(end == -1){
+    pgn_start = 0;
+    struct vm_area_struct *cur_vma = get_vma_by_num(caller->mm, 0);
+    end = cur_vma->vm_end;
+  }
+  pgn_start = PAGING_PGN(start);
+  pgn_end = PAGING_PGN(end);
+
+  printf("print_pgtbl: %d - %d", start, end);
+  if (caller == NULL) {printf("NULL caller\n"); return -1;}
+    printf("\n");
+
+
+  for(pgit = pgn_start; pgit < pgn_end; pgit++)
+  {
+     printf("%08ld: %08x\n", pgit * sizeof(uint32_t), caller->mm->pgd[pgit]);
+  }
+
+  return 0;
+}
+
+//#endif
diff --git a/ossim_source_code/src/os.c b/ossim_source_code/src/os.c
new file mode 100644
index 0000000..288a3c1
--- /dev/null
+++ b/ossim_source_code/src/os.c
@@ -0,0 +1,292 @@
+
+#include "cpu.h"
+#include "timer.h"
+#include "sched.h"
+#include "loader.h"
+#include "mm.h"
+
+#include <pthread.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+static int time_slot;
+static int num_cpus;
+static int done = 0;
+
+#ifdef MM_PAGING
+static int memramsz;
+static int memswpsz[PAGING_MAX_MMSWP];
+#ifdef MM_PAGING_HEAP_GODOWN
+static int vmemsz;
+#endif
+
+struct mmpaging_ld_args {
+	/* A dispatched argument struct to compact many-fields passing to loader */
+	int vmemsz;
+	struct memphy_struct *mram;
+	struct memphy_struct **mswp;
+	struct memphy_struct *active_mswp;
+	struct timer_id_t  *timer_id;
+};
+#endif
+
+static struct ld_args{
+	char ** path;
+	unsigned long * start_time;
+#ifdef MLQ_SCHED
+	unsigned long * prio;
+#endif
+} ld_processes;
+int num_processes;
+
+struct cpu_args {
+	struct timer_id_t * timer_id;
+	int id;
+};
+
+
+static void * cpu_routine(void * args) {
+	struct timer_id_t * timer_id = ((struct cpu_args*)args)->timer_id;
+	int id = ((struct cpu_args*)args)->id;
+	/* Check for new process in ready queue */
+	int time_left = 0;
+	struct pcb_t * proc = NULL;
+	while (1) {
+		/* Check the status of current process */
+		if (proc == NULL) {
+			/* No process is running, the we load new process from
+		 	* ready queue */
+			proc = get_proc();
+			if (proc == NULL) {
+                           next_slot(timer_id);
+                           continue; /* First load failed. skip dummy load */
+                        }
+		}else if (proc->pc == proc->code->size) {
+			/* The porcess has finish it job */
+			printf("\tCPU %d: Processed %2d has finished\n",
+				id ,proc->pid);
+			free(proc);
+			proc = get_proc();
+			time_left = 0;
+		}else if (time_left == 0) {
+			/* The process has done its job in current time slot */
+			printf("\tCPU %d: Put process %2d to run queue\n",
+				id, proc->pid);
+			put_proc(proc);
+			proc = get_proc();
+		}
+		
+		/* Recheck process status after loading new process */
+		if (proc == NULL && done) {
+			/* No process to run, exit */
+			printf("\tCPU %d stopped\n", id);
+			break;
+		}else if (proc == NULL) {
+			/* There may be new processes to run in
+			 * next time slots, just skip current slot */
+			next_slot(timer_id);
+			continue;
+		}else if (time_left == 0) {
+			printf("\tCPU %d: Dispatched process %2d\n",
+				id, proc->pid);
+			time_left = time_slot;
+		}
+		
+		/* Run current process */
+		run(proc);
+		time_left--;
+		next_slot(timer_id);
+	}
+	detach_event(timer_id);
+	pthread_exit(NULL);
+}
+
+static void * ld_routine(void * args) {
+#ifdef MM_PAGING
+	struct memphy_struct* mram = ((struct mmpaging_ld_args *)args)->mram;
+	struct memphy_struct** mswp = ((struct mmpaging_ld_args *)args)->mswp;
+	struct memphy_struct* active_mswp = ((struct mmpaging_ld_args *)args)->active_mswp;
+	struct timer_id_t * timer_id = ((struct mmpaging_ld_args *)args)->timer_id;
+#else
+	struct timer_id_t * timer_id = (struct timer_id_t*)args;
+#endif
+	int i = 0;
+	printf("ld_routine\n");
+	while (i < num_processes) {
+		struct pcb_t * proc = load(ld_processes.path[i]);
+#ifdef MLQ_SCHED
+		proc->prio = ld_processes.prio[i];
+#endif
+		while (current_time() < ld_processes.start_time[i]) {
+			next_slot(timer_id);
+		}
+#ifdef MM_PAGING
+		proc->mm = malloc(sizeof(struct mm_struct));
+#ifdef MM_PAGING_HEAP_GODOWN
+		proc->vmemsz = vmemsz;
+#endif
+		init_mm(proc->mm, proc);
+		proc->mram = mram;
+		proc->mswp = mswp;
+		proc->active_mswp = active_mswp;
+#endif
+		printf("\tLoaded a process at %s, PID: %d PRIO: %ld\n",
+			ld_processes.path[i], proc->pid, ld_processes.prio[i]);
+		add_proc(proc);
+		free(ld_processes.path[i]);
+		i++;
+		next_slot(timer_id);
+	}
+	free(ld_processes.path);
+	free(ld_processes.start_time);
+	done = 1;
+	detach_event(timer_id);
+	pthread_exit(NULL);
+}
+
+static void read_config(const char * path) {
+	FILE * file;
+	if ((file = fopen(path, "r")) == NULL) {
+		printf("Cannot find configure file at %s\n", path);
+		exit(1);
+	}
+	fscanf(file, "%d %d %d\n", &time_slot, &num_cpus, &num_processes);
+
+	ld_processes.path = (char**)malloc(sizeof(char*) * num_processes);
+	ld_processes.start_time = (unsigned long*)
+		malloc(sizeof(unsigned long) * num_processes);
+#ifdef MM_PAGING
+	int sit;
+#ifdef MM_FIXED_MEMSZ
+	/* We provide here a back compatible with legacy OS simulatiom config file
+         * In which, it have no addition config line for Mema, keep only one line
+	 * for legacy info 
+         *  [time slice] [N = Number of CPU] [M = Number of Processes to be run]
+         */
+        memramsz    =  0x100000;
+        memswpsz[0] = 0x1000000;
+	for(sit = 1; sit < PAGING_MAX_MMSWP; sit++)
+		memswpsz[sit] = 0;
+		
+#ifdef MM_PAGING_HEAP_GODOWN
+	vmemsz = 0x300000;
+#endif
+#else
+	/* Read input config of memory size: MEMRAM and upto 4 MEMSWP (mem swap)
+	 * Format: (size=0 result non-used memswap, must have RAM and at least 1 SWAP)
+	 *        MEM_RAM_SZ MEM_SWP0_SZ MEM_SWP1_SZ MEM_SWP2_SZ MEM_SWP3_SZ
+	*/
+	fscanf(file, "%d\n", &memramsz);
+	for(sit = 0; sit < PAGING_MAX_MMSWP; sit++)
+		fscanf(file, "%d", &(memswpsz[sit])); 
+#ifdef MM_PAGING_HEAP_GODOWN
+	fscanf(file, "%d\n", &vmemsz);
+#endif
+       fscanf(file, "\n"); /* Final character */
+#endif
+#endif
+
+#ifdef MLQ_SCHED
+	ld_processes.prio = (unsigned long*)
+		malloc(sizeof(unsigned long) * num_processes);
+#endif
+	int i;
+	for (i = 0; i < num_processes; i++) {
+		ld_processes.path[i] = (char*)malloc(sizeof(char) * 100);
+		ld_processes.path[i][0] = '\0';
+		strcat(ld_processes.path[i], "input/proc/");
+		char proc[100];
+#ifdef MLQ_SCHED
+		fscanf(file, "%lu %s %lu\n", &ld_processes.start_time[i], proc, &ld_processes.prio[i]);
+#else
+		fscanf(file, "%lu %s\n", &ld_processes.start_time[i], proc);
+#endif
+		strcat(ld_processes.path[i], proc);
+	}
+}
+
+int main(int argc, char * argv[]) {
+	/* Read config */
+	if (argc != 2) {
+		printf("Usage: os [path to configure file]\n");
+		return 1;
+	}
+	char path[100];
+	path[0] = '\0';
+	strcat(path, "input/");
+	strcat(path, argv[1]);
+	
+	read_config(path);
+	
+	pthread_t * cpu = (pthread_t*)malloc(num_cpus * sizeof(pthread_t));
+	struct cpu_args * args =
+		(struct cpu_args*)malloc(sizeof(struct cpu_args) * num_cpus);
+	pthread_t ld;
+	
+	/* Init timer */
+	int i;
+	for (i = 0; i < num_cpus; i++) {
+		args[i].timer_id = attach_event();
+		args[i].id = i;
+	}
+	struct timer_id_t * ld_event = attach_event();
+	start_timer();
+
+#ifdef MM_PAGING
+	/* Init all MEMPHY include 1 MEMRAM and n of MEMSWP */
+	int rdmflag = 1; /* By default memphy is RANDOM ACCESS MEMORY */
+
+	struct memphy_struct mram;
+	struct memphy_struct mswp[PAGING_MAX_MMSWP];
+
+	/* Create MEM RAM */
+	init_memphy(&mram, memramsz, rdmflag);
+
+        /* Create all MEM SWAP */ 
+	int sit;
+	for(sit = 0; sit < PAGING_MAX_MMSWP; sit++)
+	       init_memphy(&mswp[sit], memswpsz[sit], rdmflag);
+
+	/* In Paging mode, it needs passing the system mem to each PCB through loader*/
+	struct mmpaging_ld_args *mm_ld_args = malloc(sizeof(struct mmpaging_ld_args));
+
+	mm_ld_args->timer_id = ld_event;
+	mm_ld_args->mram = (struct memphy_struct *) &mram;
+	mm_ld_args->mswp = (struct memphy_struct**) &mswp;
+#ifdef MM_PAGING_HEAP_GODOWN
+	mm_ld_args->vmemsz = vmemsz;
+#endif
+	mm_ld_args->active_mswp = (struct memphy_struct *) &mswp[0];
+#endif
+
+
+	/* Init scheduler */
+	init_scheduler();
+
+	/* Run CPU and loader */
+#ifdef MM_PAGING
+	pthread_create(&ld, NULL, ld_routine, (void*)mm_ld_args);
+#else
+	pthread_create(&ld, NULL, ld_routine, (void*)ld_event);
+#endif
+	for (i = 0; i < num_cpus; i++) {
+		pthread_create(&cpu[i], NULL,
+			cpu_routine, (void*)&args[i]);
+	}
+
+	/* Wait for CPU and loader finishing */
+	for (i = 0; i < num_cpus; i++) {
+		pthread_join(cpu[i], NULL);
+	}
+	pthread_join(ld, NULL);
+
+	/* Stop timer */
+	stop_timer();
+
+	return 0;
+
+}
+
+
+
diff --git a/ossim_source_code/src/paging.c b/ossim_source_code/src/paging.c
new file mode 100644
index 0000000..b061019
--- /dev/null
+++ b/ossim_source_code/src/paging.c
@@ -0,0 +1,18 @@
+
+#include "mem.h"
+#include "cpu.h"
+#include "loader.h"
+#include <stdio.h>
+
+int main() {
+	struct pcb_t * ld = load("input/p0");
+	struct pcb_t * proc = load("input/p0");
+	unsigned int i;
+	for (i = 0; i < proc->code->size; i++) {
+		run(proc);
+		run(ld);
+	}
+	dump();
+	return 0;
+}
+
diff --git a/ossim_source_code/src/queue.c b/ossim_source_code/src/queue.c
new file mode 100644
index 0000000..6273086
--- /dev/null
+++ b/ossim_source_code/src/queue.c
@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "queue.h"
+
+int empty(struct queue_t * q) {
+        if (q == NULL) return 1;
+	return (q->size == 0);
+}
+
+void enqueue(struct queue_t * q, struct pcb_t * proc) {
+        /* TODO: put a new process to queue [q] */
+        if (q->size > MAX_QUEUE_SIZE){
+                return;
+        }
+        else if (!q->size){
+                q->proc[0] = proc;
+                q->size++;
+        }
+        else {
+                int index = q->size;
+                while (index > 0 && q->proc[index - 1]->priority > proc->priority){
+                        q->proc[index] = q->proc[index - 1];
+                        index--;
+                }
+
+                q->proc[index] = proc;
+                q->size++;
+        }
+        
+}
+
+struct pcb_t * dequeue(struct queue_t * q) {
+        /* TODO: return a pcb whose prioprity is the highest
+         * in the queue [q] and remember to remove it from q
+         * */
+        struct pcb_t * result = NULL;
+        if (q->proc[0] != NULL){
+                result = q->proc[0];
+
+                for (int i = 0; i < q->size - 1; i++){
+                        q->proc[i] = q->proc[i + 1];
+                }
+                q->proc[q->size - 1] = NULL;
+                q->size--;
+
+        }
+	return result;
+}
+
diff --git a/ossim_source_code/src/sched.c b/ossim_source_code/src/sched.c
new file mode 100644
index 0000000..c4d5ce2
--- /dev/null
+++ b/ossim_source_code/src/sched.c
@@ -0,0 +1,140 @@
+
+#include "queue.h"
+#include "sched.h"
+#include <pthread.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+static struct queue_t ready_queue;
+static struct queue_t run_queue;
+static pthread_mutex_t queue_lock;
+
+#ifdef MLQ_SCHED
+static struct queue_t mlq_ready_queue[MAX_PRIO];
+#endif
+
+int queue_empty(void) {
+#ifdef MLQ_SCHED
+	unsigned long prio;
+	for (prio = 0; prio < MAX_PRIO; prio++)
+		if(!empty(&mlq_ready_queue[prio])) 
+			return -1;
+#endif
+	return (empty(&ready_queue) && empty(&run_queue));
+}
+
+void init_scheduler(void) {
+#ifdef MLQ_SCHED
+    int i ;
+
+	for (i = 0; i < MAX_PRIO; i ++)
+		mlq_ready_queue[i].size = 0;
+#endif
+	ready_queue.size = 0;
+	run_queue.size = 0;
+	pthread_mutex_init(&queue_lock, NULL);
+}
+
+#ifdef MLQ_SCHED
+/* 
+ *  Stateful design for routine calling
+ *  based on the priority and our MLQ policy
+ *  We implement stateful here using transition technique
+ *  State representation   prio = 0 .. MAX_PRIO, curr_slot = 0..(MAX_PRIO - prio)
+ */
+struct pcb_t * get_mlq_proc(void) {
+	struct pcb_t * proc = NULL;
+	/*TODO: get a process from PRIORITY [ready_queue].
+	 * Remember to use lock to protect the queue.
+	 * */
+	//int curr_slot = 0;
+	pthread_mutex_lock(&queue_lock);
+	int prio;
+
+	for (prio = 0; prio < MAX_PRIO; prio++){
+		if (mlq_ready_queue[prio].size != 0 && mlq_ready_queue[prio].count_slot < MAX_PRIO - prio){
+			proc = dequeue(&mlq_ready_queue[prio]);
+			mlq_ready_queue[prio].count_slot++;
+			break;
+		}
+	}
+
+	if (prio == MAX_PRIO) {
+		for (int i = 0; i < MAX_PRIO; i++){
+			mlq_ready_queue[i].count_slot = 0;
+		}
+
+		for (int i = 0; i < MAX_PRIO; i++){
+			if (mlq_ready_queue[i].size != 0 && mlq_ready_queue[i].count_slot < MAX_PRIO - i){
+				proc = dequeue(&mlq_ready_queue[i]);
+				mlq_ready_queue[i].count_slot++;
+			break;
+			}
+		}
+	}
+
+	// while (prio < MAX_PRIO){
+	// 	curr_slot = MAX_PRIO - prio;
+	// 	if (!empty(&mlq_ready_queue[prio]) && mlq_ready_queue[prio].count_slot < curr_slot){
+	// 		proc = dequeue(&mlq_ready_queue[prio]);
+	// 		curr_slot--;
+	// 		break;
+	// 	}
+	// 	else{
+	// 		prio = (prio + 1) % MAX_PRIO;
+	// 		curr_slot = 0;
+	// 	}
+	// }
+	pthread_mutex_unlock(&queue_lock);
+	return proc;	
+}
+
+void put_mlq_proc(struct pcb_t * proc) {
+	pthread_mutex_lock(&queue_lock);
+	enqueue(&mlq_ready_queue[proc->prio], proc);
+	pthread_mutex_unlock(&queue_lock);
+}
+
+void add_mlq_proc(struct pcb_t * proc) {
+	pthread_mutex_lock(&queue_lock);
+	enqueue(&mlq_ready_queue[proc->prio], proc);
+	pthread_mutex_unlock(&queue_lock);	
+}
+
+struct pcb_t * get_proc(void) {
+	return get_mlq_proc();
+}
+
+void put_proc(struct pcb_t * proc) {
+	return put_mlq_proc(proc);
+}
+
+void add_proc(struct pcb_t * proc) {
+	return add_mlq_proc(proc);
+}
+#else
+struct pcb_t * get_proc(void) {
+	struct pcb_t * proc = NULL;
+	/*TODO: get a process from [ready_queue].
+	 * Remember to use lock to protect the queue.
+	 * */
+	pthread_mutex_lock(&queue_lock);
+	dequeue(&ready_queue);
+	pthread_mutex_unlock(&queue_lock);
+	return proc;
+}
+
+void put_proc(struct pcb_t * proc) {
+	pthread_mutex_lock(&queue_lock);
+	enqueue(&run_queue, proc);
+	pthread_mutex_unlock(&queue_lock);
+}
+
+void add_proc(struct pcb_t * proc) {
+	pthread_mutex_lock(&queue_lock);
+	enqueue(&ready_queue, proc);
+	pthread_mutex_unlock(&queue_lock);	
+}
+#endif
+
+
diff --git a/ossim_source_code/src/timer.c b/ossim_source_code/src/timer.c
new file mode 100644
index 0000000..02c4111
--- /dev/null
+++ b/ossim_source_code/src/timer.c
@@ -0,0 +1,136 @@
+
+#include "timer.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+static pthread_t _timer;
+
+struct timer_id_container_t {
+	struct timer_id_t id;
+	struct timer_id_container_t * next;
+};
+
+static struct timer_id_container_t * dev_list = NULL;
+
+static uint64_t _time;
+
+static int timer_started = 0;
+static int timer_stop = 0;
+
+
+static void * timer_routine(void * args) {
+	while (!timer_stop) {
+		printf("Time slot %3lu\n", current_time());
+		int fsh = 0;
+		int event = 0;
+		/* Wait for all devices have done the job in current
+		 * time slot */
+		struct timer_id_container_t * temp;
+		for (temp = dev_list; temp != NULL; temp = temp->next) {
+			pthread_mutex_lock(&temp->id.event_lock);
+			while (!temp->id.done && !temp->id.fsh) {
+				pthread_cond_wait(
+					&temp->id.event_cond,
+					&temp->id.event_lock
+				);
+			}
+			if (temp->id.fsh) {
+				fsh++;
+			}
+			event++;
+			pthread_mutex_unlock(&temp->id.event_lock);
+		}
+
+		/* Increase the time slot */
+		_time++;
+		
+		/* Let devices continue their job */
+		for (temp = dev_list; temp != NULL; temp = temp->next) {
+			pthread_mutex_lock(&temp->id.timer_lock);
+			temp->id.done = 0;
+			pthread_cond_signal(&temp->id.timer_cond);
+			pthread_mutex_unlock(&temp->id.timer_lock);
+		}
+		if (fsh == event) {
+			break;
+		}
+	}
+	pthread_exit(args);
+}
+
+void next_slot(struct timer_id_t * timer_id) {
+	/* Tell to timer that we have done our job in current slot */
+	pthread_mutex_lock(&timer_id->event_lock);
+	timer_id->done = 1;
+	pthread_cond_signal(&timer_id->event_cond);
+	pthread_mutex_unlock(&timer_id->event_lock);
+
+	/* Wait for going to next slot */
+	pthread_mutex_lock(&timer_id->timer_lock);
+	while (timer_id->done) {
+		pthread_cond_wait(
+			&timer_id->timer_cond,
+			&timer_id->timer_lock
+		);
+	}
+	pthread_mutex_unlock(&timer_id->timer_lock);
+}
+
+uint64_t current_time() {
+	return _time;
+}
+
+void start_timer() {
+	timer_started = 1;
+	pthread_create(&_timer, NULL, timer_routine, NULL);
+}
+
+void detach_event(struct timer_id_t * event) {
+	pthread_mutex_lock(&event->event_lock);
+	event->fsh = 1;
+	pthread_cond_signal(&event->event_cond);
+	pthread_mutex_unlock(&event->event_lock);
+}
+
+struct timer_id_t * attach_event() {
+	if (timer_started) {
+		return NULL;
+	}else{
+		struct timer_id_container_t * container =
+			(struct timer_id_container_t*)malloc(
+				sizeof(struct timer_id_container_t)		
+			);
+		container->id.done = 0;
+		container->id.fsh = 0;
+		pthread_cond_init(&container->id.event_cond, NULL);
+		pthread_mutex_init(&container->id.event_lock, NULL);
+		pthread_cond_init(&container->id.timer_cond, NULL);
+		pthread_mutex_init(&container->id.timer_lock, NULL);
+		if (dev_list == NULL) {
+			dev_list = container;
+			dev_list->next = NULL;
+		}else{
+			container->next = dev_list;
+			dev_list = container;
+		}
+		return &(container->id);
+	}
+}
+
+void stop_timer() {
+	timer_stop = 1;
+	pthread_join(_timer, NULL);
+	while (dev_list != NULL) {
+		struct timer_id_container_t * temp = dev_list;
+		dev_list = dev_list->next;
+		pthread_cond_destroy(&temp->id.event_cond);
+		pthread_mutex_destroy(&temp->id.event_lock);
+		pthread_cond_destroy(&temp->id.timer_cond);
+		pthread_mutex_destroy(&temp->id.timer_lock);
+		free(temp);
+	}
+}
+
+
+
+