KernelPrint

functions

• kvprintf - general kernel print formatter, needs putc style output func
• lprintf - prints directly and only to debug console (serial 0 on PC and most builds, goes to QEMU log file too), slow, can work in closed interrupts and interrupt handlers, see $ARCH/debug_console.c
• SHOW_ERROR/SHOW_FLOW/SHOW_INFO - see below, main kernel logging, goes to debug window and debug console

kvprintf additional formats

%b

The format %b is supported to decode error registers.

Its usage is:

printf("reg=%b\n", regval, "<base><arg>*");

Where is the output base expressed as a control character, e.g. \10 gives octal; \20 gives hex. Each arg is a sequence of characters, the first of which gives the bit number to be inspected (origin 1), and the next characters (up to a control character, i.e. a character <= 32), give the name of the register. Thus:

kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");

would produce output:

reg=3<BITTWO,BITONE>

%D

Hexdump, takes pointer and separator string:

		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
		("%*D", len, ptr, " " -> XX XX XX XX ...

debug_ext.h

#define DEBUG_MSG_PREFIX "port"
#include <debug_ext.h>
#define debug_level_flow 10
#define debug_level_error 10
#define debug_level_info 10

SHOW_ERROR0( 0, "Failed" ); // No printf args
SHOW_ERROR( 1, "Hash remove fail for %s", el->name ); // Has args, will print if debug_level_error >= 1
SHOW_FLOW0( 0, "port handle init"); // Flow control debug prints
SHOW_INFO( 0, "irq = %d", irq ); // Regular logging