xv6-cs450/console.c
rtm 8148b6ee53 i think my cmpxchg use was wrong in acquire
nesting cli/sti: release shouldn't always enable interrupts
separate setup of lapic from starting of other cpus, so cpu() works earlier
flag to disable locking in console output
make locks work even when curproc==0
(still crashes in clock interrupt)
2006-07-12 11:15:38 +00:00

139 lines
2.3 KiB
C

#include <types.h>
#include <x86.h>
#include "defs.h"
#include "spinlock.h"
struct spinlock console_lock;
int use_printf_lock = 0;
/*
* copy console output to parallel port, which you can tell
* .bochsrc to copy to the stdout:
* parport1: enabled=1, file="/dev/stdout"
*/
static void
lpt_putc(int c)
{
int i;
for (i = 0; !(inb(0x378+1) & 0x80) && i < 12800; i++)
;
outb(0x378+0, c);
outb(0x378+2, 0x08|0x04|0x01);
outb(0x378+2, 0x08);
}
void
cons_putc(int c)
{
int crtport = 0x3d4; // io port of CGA
unsigned short *crt = (unsigned short *) 0xB8000; // base of CGA memory
int ind;
if(use_printf_lock)
acquire(&console_lock);
lpt_putc(c);
// 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);
if(use_printf_lock)
release(&console_lock);
}
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' || c == 'p'){
printint(*ap, 16, 0);
ap++;
} else if(c == '%'){
cons_putc(c);
}
state = 0;
}
}
}
void
panic(char *s)
{
use_printf_lock = 0;
cprintf("panic: ");
cprintf(s, 0);
cprintf("\n", 0);
while(1)
;
}