Gynvael Stream Competition - OSDev, Guru Panic of Death

competition-osdev-08-pajadam/.gitignore

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+bin
+tmp
+*.pyc

competition-osdev-08-pajadam/README.md

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+# How to build and run project?
+
+You need to use simple Python script. Just run it `python manage.py` with one of following arguments:
+
+- `build` - generate our disk image
+- `run` - run generated disk image in bochs
+- `test` - `build` and `run`
+- `clean` - empty temp directory
+
+# What is in project's directories?
+
+- /src     - Code
+- /scripts - Building scripts in python
+- /conf    - Bochs config
+- /bin     - Generated disk image
+- /tmp     - Directory with temporary files

competition-osdev-08-pajadam/manage.py

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+from scripts import build, run
+import shutil
+import sys
+import os
+
+
+def main():
+
+    try:
+        # Add missing directories if needed
+        for directory in ("tmp", "bin",):
+            if not os.path.exists(directory):
+                os.makedirs(directory)
+
+        # Parse console arguments
+        if len(sys.argv) == 2:
+            os.chdir("tmp/")
+            if sys.argv[1] == "build":
+                build()
+            elif sys.argv[1] == "run":
+                run()
+            elif sys.argv[1] == "test":
+                build()
+                run()
+            elif sys.argv[1] == "clean":
+                os.chdir("..")
+                shutil.rmtree("tmp")
+                print "Cleaned ./tmp directory."
+            else:
+                raise ValueError("Invalid argument: " + sys.argv[1])
+        else:
+            raise ValueError("Missing arguments")
+
+    except ValueError as exc:
+        print exc
+        print "Usage:"
+        print "  build\t- Build project"
+        print "  run\t- Run project"
+        print "  test\t- Build and run project"
+        print "  clean\t- Clean temporary directory\n"
+
+    except Exception as exc:
+        print exc
+
+
+if __name__ == "__main__":
+    main()

competition-osdev-08-pajadam/scripts/__init__.py

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+from .build import *
+from .run import *

competition-osdev-08-pajadam/scripts/build.py

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+#!/usr/bin/python
+import os
+import sys
+import subprocess
+from glob import glob
+
+
+def fix_stage1_size():
+    stage2_size = os.stat("stage2").st_size
+    kernel_size = os.stat("kernel64").st_size
+
+    stage2_size = (stage2_size + kernel_size + 511) / 512
+
+    if stage2_size >= 255:
+        raise Exception("stage2 & kernel are too large")
+
+    with open("stage1", "rb+") as f:
+        d = f.read()
+        idx = d.index("\xb0\xcc\x90\x90")
+        d = bytearray(d)
+        d[idx + 1] = stage2_size
+        f.seek(0)
+        f.write(d)
+
+
+def build():
+    """ Build disk image with OS """
+    cmds_to_run = []
+
+    cc_flags = "-std=c99 -nostdlib -c -O0 -Wall -Wextra -masm=intel -ggdb"
+    ld_flags = "-std=c99 -nostdlib -o kernel64 -O0 -Wall -Wextra -masm=intel -ggdb"
+
+    objfiles = []
+
+    for fname in glob("../src/os/*.c"):
+        cmds_to_run.append("gcc %s %s" % (fname, cc_flags))
+        objfiles.append("%s.o" % os.path.basename(os.path.splitext(fname)[0]))
+
+    as_flags = "-masm=intel -ggdb -c"
+
+    for fname in glob("../src/os/*.s"):
+        cmds_to_run.append("gcc %s %s" % (fname, as_flags))
+        objfiles.append("%s.o" % os.path.basename(os.path.splitext(fname)[0]))
+
+    cmds_to_run.extend([
+        "gcc %s %s" % (' '.join(objfiles), ld_flags),
+        "strip kernel64",
+        "nasm ../src/boot/stage1.asm -o stage1",
+        "nasm ../src/boot/stage2.asm -o stage2",
+        fix_stage1_size
+    ])
+
+    files_to_img = [
+        "stage1",
+        "stage2",
+        "kernel64"
+    ]
+
+    for cmd in cmds_to_run:
+        if type(cmd) is str:
+            print "Running:", cmd
+            print subprocess.check_output(cmd, shell=True)
+        else:
+            print "Calling:", cmd.func_name
+            cmd()
+
+    buf = []
+    for fn in files_to_img:
+        with open(fn, "rb") as f:
+            d = f.read()
+            buf.append(d)
+
+            if len(d) % 512 == 0:
+                continue
+
+            padding_size = 512 - len(d) % 512
+            buf.append("\0" * padding_size)
+
+    with open("../bin/floppy.bin", "wb") as f:
+        f.write(''.join(buf))

competition-osdev-08-pajadam/scripts/run.py

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+from subprocess import call
+import os
+
+
+def run():
+    if not os.path.exists('../conf/osdev.bochsrc'):
+        raise Exception('Missing bochs config!')
+
+    if not os.path.exists('../bin/floppy.bin'):
+        raise Exception("Missing disk image.\nYou should run 'python manage.py build' first.")
+
+    print "Running bochs..."
+    call('bochs -f "../conf/osdev.bochsrc"', shell=True)

competition-osdev-08-pajadam/src/boot/stage1.asm

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+[bits 16]
+[org 0x7c00]
+; 0x7c00
+; SEGMENT:OFFSET
+; adres = SEGMENT * 0x10 + OFFSET
+; CS 07c0  0000
+; IP 0000  7c00
+;          ****
+
+jmp word 0x0000:start
+
+start:
+  ;mov ax, 0xb800
+  ;mov es, ax
+  ;xor di, di
+  ;mov word [es:di], 0x4141
+  ;jmp $
+
+  ; Load from floppy stage 2.
+  ; DL == already set by BIOS
+  ; AX -- 16 bits, AH AL -- 8 bits
+  ; EAX -- AX
+
+  mov ax, 0x2000 ; 0x2000:0x0000
+  mov es, ax
+  xor bx, bx ; bx == 0
+
+  mov ah, 2  ; read sectors into memory
+  mov al, 0xcc  ; 1337 stage2  3 * 512
+  nop
+  nop
+  mov ch, 0
+  mov cl, 2  ; sectors start from 1, or so they say ;)
+  mov dh, 0
+
+  int 13h
+
+  ; Jump to stage 2
+  jmp word 0x2000:0x0000
+
+  ; The CPU doesn't reach here. Ever. Hopefully.
+
+epilogue:
+%if ($ - $$) > 510
+  %fatal "Bootloader code exceed 512 bytes."
+%endif
+
+times 510 - ($ - $$) db 0
+db 0x55
+db 0xAA
+
+
+
+