console.c

#include "types.h"
#include "x86.h"
#include "defs.h"
#include "spinlock.h"
#include "dev.h"
#include "param.h"

struct spinlock console_lock;
int panicked = 0;
int use_console_lock = 0;

// per-cpu copy of output to help panic/lock debugging
char obuf[NCPU][1024];
uint obufi[NCPU];

/*
 * 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
cons_putc(int c)
{
  int crtport = 0x3d4; // io port of CGA
  ushort *crt = (ushort *) 0xB8000; // base of CGA memory
  int ind;

  obuf[rcr4()][obufi[rcr4()]++] = c;
  if(obufi[rcr4()] >= 1024)
    obufi[rcr4()] = 0;

  if(panicked){
    cli();
    for(;;)
      ;
  }

  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++;
  }

  if((ind / 80) >= 24){
    // scroll up
    memmove(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;
  uint 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)
    cons_putc(buf[i]);
}

/*
 * print to the console. only understands %d, %x, %p, %s.
 */
void
cprintf(char *fmt, ...)
{
  int i, state = 0, c, locking = 0;
  uint *ap = (uint *)(void*)&fmt + 1;

  if(use_console_lock){
    locking = 1;
    acquire(&console_lock);
  }

  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 == 's'){
        char *s = (char*)*ap;
        ap++;
        while(*s != 0){
          cons_putc(*s);
          s++;
        }
      } else if(c == '%'){
        cons_putc(c);
      } else {
        // Unknown % sequence.  Print it to draw attention.
        cons_putc('%');
        cons_putc(c);
      }
      state = 0;
    }
  }

  if(locking)
    release(&console_lock);
}

void
panic(char *s)
{
  __asm __volatile("cli");
  use_console_lock = 0;
  cprintf("panic: ");
  cprintf(s, 0);
  cprintf("\n", 0);
  panicked = 1; // freeze other CPU
  for(;;)
    ;
}

int
console_write (int minor, char *buf, int n)
{
  int i;

  acquire(&console_lock);

  for (i = 0; i < n; i++) {
    cons_putc(buf[i] & 0xff);
  }

  release(&console_lock);

  return n;
}


/* This is i8042reg.h + kbdreg.h from NetBSD. */
#define	KBSTATP		0x64	/* kbd controller status port(I) */
#define	 KBS_DIB	0x01	/* kbd data in buffer */
#define	KBDATAP		0x60	/* kbd data port(I) */

#define NO		0

#define SHIFT		(1<<0)
#define CTL		(1<<1)
#define ALT		(1<<2)

#define CAPSLOCK	(1<<3)
#define NUMLOCK		(1<<4)
#define SCROLLLOCK	(1<<5)

#define E0ESC		(1<<6)

// Special keycodes
#define KEY_HOME	0xE0
#define KEY_END		0xE1
#define KEY_UP		0xE2
#define KEY_DN		0xE3
#define KEY_LF		0xE4
#define KEY_RT		0xE5
#define KEY_PGUP	0xE6
#define KEY_PGDN	0xE7
#define KEY_INS		0xE8
#define KEY_DEL		0xE9

static uchar shiftcode[256] = 
{
	[0x1D] CTL,
	[0x2A] SHIFT,
	[0x36] SHIFT,
	[0x38] ALT,
	[0x9D] CTL,
	[0xB8] ALT
};

static uchar togglecode[256] = 
{
	[0x3A] CAPSLOCK,
	[0x45] NUMLOCK,
	[0x46] SCROLLLOCK
};

static uchar normalmap[256] =
{
	NO,   0x1B, '1',  '2',  '3',  '4',  '5',  '6',	// 0x00
	'7',  '8',  '9',  '0',  '-',  '=',  '\b', '\t',
	'q',  'w',  'e',  'r',  't',  'y',  'u',  'i',	// 0x10
	'o',  'p',  '[',  ']',  '\n', NO,   'a',  's',
	'd',  'f',  'g',  'h',  'j',  'k',  'l',  ';',	// 0x20
	'\'', '`',  NO,   '\\', 'z',  'x',  'c',  'v',
	'b',  'n',  'm',  ',',  '.',  '/',  NO,   '*',	// 0x30
	NO,   ' ',  NO,   NO,   NO,   NO,   NO,   NO,
	NO,   NO,   NO,   NO,   NO,   NO,   NO,   '7',	// 0x40
	'8',  '9',  '-',  '4',  '5',  '6',  '+',  '1',
	'2',  '3',  '0',  '.',  NO,   NO,   NO,   NO,	// 0x50
	[0x97] KEY_HOME,	[0x9C] '\n' /*KP_Enter*/,
	[0xB5] '/' /*KP_Div*/,	[0xC8] KEY_UP,
	[0xC9] KEY_PGUP,	[0xCB] KEY_LF,
	[0xCD] KEY_RT,		[0xCF] KEY_END,
	[0xD0] KEY_DN,		[0xD1] KEY_PGDN,
	[0xD2] KEY_INS,		[0xD3] KEY_DEL
};

static uchar shiftmap[256] = 
{
	NO,   033,  '!',  '@',  '#',  '$',  '%',  '^',	// 0x00
	'&',  '*',  '(',  ')',  '_',  '+',  '\b', '\t',
	'Q',  'W',  'E',  'R',  'T',  'Y',  'U',  'I',	// 0x10
	'O',  'P',  '{',  '}',  '\n', NO,   'A',  'S',
	'D',  'F',  'G',  'H',  'J',  'K',  'L',  ':',	// 0x20
	'"',  '~',  NO,   '|',  'Z',  'X',  'C',  'V',
	'B',  'N',  'M',  '<',  '>',  '?',  NO,   '*',	// 0x30
	NO,   ' ',  NO,   NO,   NO,   NO,   NO,   NO,
	NO,   NO,   NO,   NO,   NO,   NO,   NO,   '7',	// 0x40
	'8',  '9',  '-',  '4',  '5',  '6',  '+',  '1',
	'2',  '3',  '0',  '.',  NO,   NO,   NO,   NO,	// 0x50
	[0x97] KEY_HOME,	[0x9C] '\n' /*KP_Enter*/,
	[0xB5] '/' /*KP_Div*/,	[0xC8] KEY_UP,
	[0xC9] KEY_PGUP,	[0xCB] KEY_LF,
	[0xCD] KEY_RT,		[0xCF] KEY_END,
	[0xD0] KEY_DN,		[0xD1] KEY_PGDN,
	[0xD2] KEY_INS,		[0xD3] KEY_DEL
};

#define C(x) (x - '@')

static uchar ctlmap[256] = 
{
	NO,      NO,      NO,      NO,      NO,      NO,      NO,      NO, 
	NO,      NO,      NO,      NO,      NO,      NO,      NO,      NO, 
	C('Q'),  C('W'),  C('E'),  C('R'),  C('T'),  C('Y'),  C('U'),  C('I'),
	C('O'),  C('P'),  NO,      NO,      '\r',    NO,      C('A'),  C('S'),
	C('D'),  C('F'),  C('G'),  C('H'),  C('J'),  C('K'),  C('L'),  NO, 
	NO,      NO,      NO,      C('\\'), C('Z'),  C('X'),  C('C'),  C('V'),
	C('B'),  C('N'),  C('M'),  NO,      NO,      C('/'),  NO,      NO,
	[0x97] KEY_HOME,
	[0xB5] C('/'),		[0xC8] KEY_UP,
	[0xC9] KEY_PGUP,	[0xCB] KEY_LF,
	[0xCD] KEY_RT,		[0xCF] KEY_END,
	[0xD0] KEY_DN,		[0xD1] KEY_PGDN,
	[0xD2] KEY_INS,		[0xD3] KEY_DEL
};

static uchar *charcode[4] = {
	normalmap,
	shiftmap,
	ctlmap,
	ctlmap
};

#define KBD_BUF 64
char kbd_buf[KBD_BUF];
int kbd_r;
int kbd_w;
struct spinlock kbd_lock;

void
kbd_intr()
{
  uint st, data, c;
  static uint shift;

  st = inb(KBSTATP);
  if ((st & KBS_DIB) == 0){
    return;
  }
  data = inb(KBDATAP);

  if (data == 0xE0) {
    shift |= E0ESC;
    return;
  } else if (data & 0x80) {
    // Key released
    data = (shift & E0ESC ? data : data & 0x7F);
    shift &= ~(shiftcode[data] | E0ESC);
    return;
  } else if (shift & E0ESC) {
    // Last character was an E0 escape; or with 0x80
    data |= 0x80;
    shift &= ~E0ESC;
  }
  
  shift |= shiftcode[data];
  shift ^= togglecode[data];
  
  c = charcode[shift & (CTL | SHIFT)][data];
  if (shift & CAPSLOCK) {
    if ('a' <= c && c <= 'z')
      c += 'A' - 'a';
    else if ('A' <= c && c <= 'Z')
      c += 'a' - 'A';
  }
  
  acquire(&kbd_lock);

  if(((kbd_w + 1) % KBD_BUF) != kbd_r){
    kbd_buf[kbd_w++] = c;
    if(kbd_w >= KBD_BUF)
      kbd_w = 0;
    wakeup(&kbd_r);
  } else {
    cprintf("kbd overflow\n");
  }

  release(&kbd_lock);
}

int
console_read(int minor, char *dst, int n)
{
  uint target = n;

  acquire(&kbd_lock);

  while(kbd_w == kbd_r)
    sleep(&kbd_r, &kbd_lock);

  while(n > 0 && kbd_w != kbd_r){
    *dst = kbd_buf[kbd_r];
    cons_putc(*dst & 0xff);
    dst++;
    --n;
    kbd_r++;
    if(kbd_r >= KBD_BUF)
      kbd_r = 0;
  }

  release(&kbd_lock);

  return target - n;
}

void
console_init()
{
  initlock(&console_lock, "console");
  initlock(&kbd_lock, "kbd");

  devsw[CONSOLE].d_write = console_write;
  devsw[CONSOLE].d_read = console_read;

  ioapic_enable (IRQ_KBD, 1);

  use_console_lock = 1;
}