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// Console input and output.
// Input is from the keyboard or serial port.
// Output is written to the screen and serial port.
#include "types.h"
#include "defs.h"
#include "param.h"
#include "traps.h"
#include "spinlock.h"
#include "fs.h"
#include "file.h"
#include "memlayout.h"
#include "mmu.h"
#include "proc.h"
#include "x86.h"
static void consputc(int);
static int panicked = 0;
static struct {
struct spinlock lock;
int locking;
} cons;
static void
printint(int xx, int base, int sign)
{
static char digits[] = "0123456789abcdef";
char buf[16];
int i;
uint x;
if(sign && (sign = xx < 0))
x = -xx;
else
x = xx;
i = 0;
do{
buf[i++] = digits[x % base];
}while((x /= base) != 0);
if(sign)
buf[i++] = '-';
while(--i >= 0)
consputc(buf[i]);
}
//PAGEBREAK: 50
// Print to the console. only understands %d, %x, %p, %s.
void
cprintf(char *fmt, ...)
{
int i, c, locking;
uint *argp;
char *s;
locking = cons.locking;
if(locking)
acquire(&cons.lock);
if (fmt == 0)
panic("null fmt");
argp = (uint*)(void*)(&fmt + 1);
for(i = 0; (c = fmt[i] & 0xff) != 0; i++){
if(c != '%'){
consputc(c);
continue;
}
c = fmt[++i] & 0xff;
if(c == 0)
break;
switch(c){
case 'd':
printint(*argp++, 10, 1);
break;
case 'x':
case 'p':
printint(*argp++, 16, 0);
break;
case 's':
if((s = (char*)*argp++) == 0)
s = "(null)";
for(; *s; s++)
consputc(*s);
break;
case '%':
consputc('%');
break;
default:
// Print unknown % sequence to draw attention.
consputc('%');
consputc(c);
break;
}
}
if(locking)
release(&cons.lock);
}
void
panic(char *s)
{
int i;
uint pcs[10];
cli();
cons.locking = 0;
cprintf("cpu%d: panic: ", cpu->id);
cprintf(s);
cprintf("\n");
getcallerpcs(&s, pcs);
for(i=0; i<10; i++)
cprintf(" %p", pcs[i]);
panicked = 1; // freeze other CPU
for(;;)
;
}
//PAGEBREAK: 50
#define BACKSPACE 0x100
#define CRTPORT 0x3d4
static ushort *crt = (ushort*)P2V(0xb8000); // CGA memory
static void
cgaputc(int c)
{
int pos;
// Cursor position: col + 80*row.
outb(CRTPORT, 14);
pos = inb(CRTPORT+1) << 8;
outb(CRTPORT, 15);
pos |= inb(CRTPORT+1);
if(c == '\n')
pos += 80 - pos%80;
else if(c == BACKSPACE){
if(pos > 0) --pos;
} else
crt[pos++] = (c&0xff) | 0x0700; // black on white
if((pos/80) >= 24){ // Scroll up.
memmove(crt, crt+80, sizeof(crt[0])*23*80);
pos -= 80;
memset(crt+pos, 0, sizeof(crt[0])*(24*80 - pos));
}
outb(CRTPORT, 14);
outb(CRTPORT+1, pos>>8);
outb(CRTPORT, 15);
outb(CRTPORT+1, pos);
crt[pos] = ' ' | 0x0700;
}
void
consputc(int c)
{
if(panicked){
cli();
for(;;)
;
}
if(c == BACKSPACE){
uartputc('\b'); uartputc(' '); uartputc('\b');
} else
uartputc(c);
cgaputc(c);
}
#define INPUT_BUF 128
struct {
struct spinlock lock;
char buf[INPUT_BUF];
uint r; // Read index
uint w; // Write index
uint e; // Edit index
} input;
#define C(x) ((x)-'@') // Control-x
void
consoleintr(int (*getc)(void))
{
int c;
acquire(&input.lock);
while((c = getc()) >= 0){
switch(c){
case C('P'): // Process listing.
procdump();
break;
case C('U'): // Kill line.
while(input.e != input.w &&
input.buf[(input.e-1) % INPUT_BUF] != '\n'){
input.e--;
consputc(BACKSPACE);
}
break;
case C('H'): case '\x7f': // Backspace
if(input.e != input.w){
input.e--;
consputc(BACKSPACE);
}
break;
default:
if(c != 0 && input.e-input.r < INPUT_BUF){
c = (c == '\r') ? '\n' : c;
input.buf[input.e++ % INPUT_BUF] = c;
consputc(c);
if(c == '\n' || c == C('D') || input.e == input.r+INPUT_BUF){
input.w = input.e;
wakeup(&input.r);
}
}
break;
}
}
release(&input.lock);
}
int
consoleread(struct inode *ip, char *dst, int n)
{
uint target;
int c;
iunlock(ip);
target = n;
acquire(&input.lock);
while(n > 0){
while(input.r == input.w){
if(proc->killed){
release(&input.lock);
ilock(ip);
return -1;
}
sleep(&input.r, &input.lock);
}
c = input.buf[input.r++ % INPUT_BUF];
if(c == C('D')){ // EOF
if(n < target){
// Save ^D for next time, to make sure
// caller gets a 0-byte result.
input.r--;
}
break;
}
*dst++ = c;
--n;
if(c == '\n')
break;
}
release(&input.lock);
ilock(ip);
return target - n;
}
int
consolewrite(struct inode *ip, char *buf, int n)
{
int i;
iunlock(ip);
acquire(&cons.lock);
for(i = 0; i < n; i++)
consputc(buf[i] & 0xff);
release(&cons.lock);
ilock(ip);
return n;
}
void
consoleinit(void)
{
initlock(&cons.lock, "console");
initlock(&input.lock, "input");
devsw[CONSOLE].write = consolewrite;
devsw[CONSOLE].read = consoleread;
cons.locking = 1;
picenable(IRQ_KBD);
ioapicenable(IRQ_KBD, 0);
}