xv6-65oo2/console.c
2006-06-12 15:22:12 +00:00

109 lines
1.8 KiB
C

#include <types.h>
#include <x86.h>
#include "defs.h"
void
cons_putc(int c)
{
int crtport = 0x3d4; // io port of CGA
unsigned short *crt = (unsigned short *) 0xB8000; // base of CGA memory
int ind;
// cursor position, 16 bits, col + 80*row
outb(crtport, 14);
ind = inb(crtport + 1) << 8;
outb(crtport, 15);
ind |= inb(crtport + 1);
c &= 0xff;
if(c == '\n'){
ind -= (ind % 80);
ind += 80;
} else {
c |= 0x0700; // black on white
crt[ind] = c;
ind += 1;
}
if((ind / 80) >= 24){
// scroll up
memcpy(crt, crt + 80, sizeof(crt[0]) * (23 * 80));
ind -= 80;
memset(crt + ind, 0, sizeof(crt[0]) * ((24 * 80) - ind));
}
outb(crtport, 14);
outb(crtport + 1, ind >> 8);
outb(crtport, 15);
outb(crtport + 1, ind);
}
void
printint(int xx, int base, int sgn)
{
char buf[16];
char digits[] = "0123456789ABCDEF";
int i = 0, neg = 0;
unsigned int x;
if(sgn && xx < 0){
neg = 1;
x = 0 - xx;
} else {
x = xx;
}
do {
buf[i++] = digits[x % base];
} while((x /= base) != 0);
if(neg)
buf[i++] = '-';
while(i > 0){
i -= 1;
cons_putc(buf[i]);
}
}
/*
* print to the console. only understands %d and %x.
*/
void
cprintf(char *fmt, ...)
{
int i, state = 0, c;
unsigned int *ap = (unsigned int *) &fmt + 1;
for(i = 0; fmt[i]; i++){
c = fmt[i] & 0xff;
if(state == 0){
if(c == '%'){
state = '%';
} else {
cons_putc(c);
}
} else if(state == '%'){
if(c == 'd'){
printint(*ap, 10, 1);
ap++;
} else if(c == 'x'){
printint(*ap, 16, 0);
ap++;
} else if(c == '%'){
cons_putc(c);
}
state = 0;
}
}
}
void
panic(char *s)
{
cprintf(s, 0);
cprintf("\n", 0);
while(1)
;
}