xv6/console.c
rtm 46bbd72f3e no more recursive locks
wakeup1() assumes you hold proc_table_lock
sleep(chan, lock) provides atomic sleep-and-release to wait for condition
ugly code in swtch/scheduler to implement new sleep
fix lots of bugs in pipes, wait, and exit
fix bugs if timer interrupt goes off in schedule()
console locks per line, not per byte
2006-07-15 12:03:57 +00:00

158 lines
2.6 KiB
C

#include <types.h>
#include <x86.h>
#include "defs.h"
#include "spinlock.h"
struct spinlock console_lock;
int paniced = 0;
int use_console_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);
}
static void
real_cons_putc(int c)
{
int crtport = 0x3d4; // io port of CGA
unsigned short *crt = (unsigned short *) 0xB8000; // base of CGA memory
int ind;
if(paniced){
cli();
while(1)
;
}
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);
}
void
cons_putc(int c)
{
if(use_console_lock)
acquire(&console_lock);
real_cons_putc(c);
if(use_console_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;
real_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;
if(use_console_lock)
acquire(&console_lock);
for(i = 0; fmt[i]; i++){
c = fmt[i] & 0xff;
if(state == 0){
if(c == '%'){
state = '%';
} else {
real_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 == '%'){
real_cons_putc(c);
}
state = 0;
}
}
if(use_console_lock)
release(&console_lock);
}
void
panic(char *s)
{
__asm __volatile("cli");
use_console_lock = 0;
cprintf("panic: ");
cprintf(s, 0);
cprintf("\n", 0);
paniced = 1; // freeze other CPU
while(1)
;
}