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#include "io.h"
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#define BOCHS_PUTCHAR(ch) (outb(0xe9, ch))
void log_putchar(int ch)
{
BOCHS_PUTCHAR((char)ch);
}
void log_puts(const char* str)
{
while(*str)
log_putchar(*str++);
}
static char hex_table[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
static void log_print_hex(unsigned int n)
{
unsigned mask = 0xF0000000;
unsigned shift = 28;
while(mask)
{
log_putchar(hex_table[(n & mask) >> shift]);
mask >>= 4;
shift -= 4;
}
}
int log(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
while(*fmt)
{
char ch = *fmt++;
switch(ch)
{
case '%':
{
switch(*fmt++)
{
case 'c':
log_putchar(va_arg(ap, int));
break;
case 's':
log_puts(va_arg(ap, const char*));
break;
case 'x':
log_print_hex(va_arg(ap, unsigned));
break;
case 'd':
log_puts(itoa(va_arg(ap, unsigned), 10));
break;
default:
log_puts("klog: unknown format\n");
break;
}
break;
}
default:
log_putchar(ch);
break;
}
}
va_end(ap);
return 0;
}
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