rombios.c

xen 3.2.2 源码

/* data */
#define UART_RBR 0x00
#define UART_THR 0x00

/* control */
#define UART_IER 0x01
#define UART_IIR 0x02
#define UART_FCR 0x02
#define UART_LCR 0x03
#define UART_MCR 0x04
#define UART_DLL 0x00
#define UART_DLM 0x01

/* status */
#define UART_LSR 0x05
#define UART_MSR 0x06
#define UART_SCR 0x07

int uart_can_tx_byte(base_port)
    Bit16u base_port;
{
    return inb(base_port + UART_LSR) & 0x20;
}

void uart_wait_to_tx_byte(base_port)
    Bit16u base_port;
{
    while (!uart_can_tx_byte(base_port));
}

void uart_wait_until_sent(base_port)
    Bit16u base_port;
{
    while (!(inb(base_port + UART_LSR) & 0x40));
}

void uart_tx_byte(base_port, data)
    Bit16u base_port;
    Bit8u data;
{
    uart_wait_to_tx_byte(base_port);
    outb(base_port + UART_THR, data);
    uart_wait_until_sent(base_port);
}
#endif

  void
wrch(c)
  Bit8u  c;
{
  ASM_START
  push bp
  mov  bp, sp

  push bx
  mov  ah, #0x0e
  mov  al, 4[bp]
  xor  bx,bx
  int  #0x10
  pop  bx

  pop  bp
  ASM_END
}
 
  void
send(action, c)
  Bit16u action;
  Bit8u  c;
{
#if BX_DEBUG_SERIAL
  if (c == '\n') uart_tx_byte(BX_DEBUG_PORT, '\r');
  uart_tx_byte(BX_DEBUG_PORT, c);
#endif
#ifdef HVMASSIST
  outb(0xE9, c);
#endif
#if BX_VIRTUAL_PORTS
  if (action & BIOS_PRINTF_DEBUG) outb(DEBUG_PORT, c);
  if (action & BIOS_PRINTF_INFO) outb(INFO_PORT, c);
#endif
  if (action & BIOS_PRINTF_SCREEN) {
    if (c == '\n') wrch('\r');
    wrch(c);
  }
}

  void
put_int(action, val, width, neg)
  Bit16u action;
  short val, width;
  bx_bool neg;
{
  short nval = val / 10;
  if (nval)
    put_int(action, nval, width - 1, neg);
  else {
    while (--width > 0) send(action, ' ');
    if (neg) send(action, '-');
  }
  send(action, val - (nval * 10) + '0');
}

  void
put_uint(action, val, width, neg)
  Bit16u action;
  unsigned short val;
  short width;
  bx_bool neg;
{
  unsigned short nval = val / 10;
  if (nval)
    put_uint(action, nval, width - 1, neg);
  else {
    while (--width > 0) send(action, ' ');
    if (neg) send(action, '-');
  }
  send(action, val - (nval * 10) + '0');
}

//--------------------------------------------------------------------------
// bios_printf()
//   A compact variable argument printf function which prints its output via
//   an I/O port so that it can be logged by Bochs/Plex.  
//   Currently, only %x is supported (or %02x, %04x, etc).
//
//   Supports %[format_width][format]
//   where format can be d,x,c,s
//--------------------------------------------------------------------------
  void
bios_printf(action, s)
  Bit16u action;
  Bit8u *s;
{
  Bit8u c, format_char;
  bx_bool  in_format;
  short i;
  Bit16u  *arg_ptr;
  Bit16u   arg_seg, arg, nibble, shift_count, format_width;

  arg_ptr = &s;
  arg_seg = get_SS();

  in_format = 0;
  format_width = 0;

  if ((action & BIOS_PRINTF_DEBHALT) == BIOS_PRINTF_DEBHALT) {
#if BX_VIRTUAL_PORTS
    outb(PANIC_PORT2, 0x00);
#endif
    bios_printf (BIOS_PRINTF_SCREEN, "FATAL: ");
  }

  while (c = read_byte(get_CS(), s)) {
    if ( c == '%' ) {
      in_format = 1;
      format_width = 0;
      }
    else if (in_format) {
      if ( (c>='0') && (c<='9') ) {
        format_width = (format_width * 10) + (c - '0');
        }
      else {
        arg_ptr++; // increment to next arg
        arg = read_word(arg_seg, arg_ptr);
        if (c == 'x') {
          if (format_width == 0)
            format_width = 4;
          for (i=format_width-1; i>=0; i--) {
            nibble = (arg >> (4 * i)) & 0x000f;
            send (action, (nibble<=9)? (nibble+'0') : (nibble-10+'A'));
            }
          }
        else if (c == 'u') {
          put_uint(action, arg, format_width, 0);
          }
        else if (c == 'd') {
          if (arg & 0x8000)
            put_int(action, -arg, format_width - 1, 1);
          else
            put_int(action, arg, format_width, 0);
          }
        else if (c == 's') {
          bios_printf(action & (~BIOS_PRINTF_HALT), arg);
          }
        else if (c == 'c') {
          send(action, arg);
          }
        else
          BX_PANIC("bios_printf: unknown format\n");
          in_format = 0;
        }
      }
    else {
      send(action, c);
      }
    s ++;
    }

  if (action & BIOS_PRINTF_HALT) {
    // freeze in a busy loop.  
ASM_START
    cli
 halt2_loop:
    hlt
    jmp halt2_loop
ASM_END
    }
}

//--------------------------------------------------------------------------
// keyboard_init
//--------------------------------------------------------------------------
// this file is based on LinuxBIOS implementation of keyboard.c
// could convert to #asm to gain space
  void
keyboard_init()
{
    Bit16u max;

    /* ------------------- Flush buffers ------------------------*/
    /* Wait until buffer is empty */
    max=0xffff;
    while ( (inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x00);

    /* flush incoming keys */
    max=0x2000;
    while (--max > 0) {
        outb(0x80, 0x00);
        if (inb(0x64) & 0x01) {
            inb(0x60);
            max = 0x2000;
            }
        }
  
    // Due to timer issues, and if the IPS setting is > 15000000, 
    // the incoming keys might not be flushed here. That will
    // cause a panic a few lines below.  See sourceforge bug report :
    // [ 642031 ] FATAL: Keyboard RESET error:993

    /* ------------------- controller side ----------------------*/
    /* send cmd = 0xAA, self test 8042 */
    outb(0x64, 0xaa);

    /* Wait until buffer is empty */
    max=0xffff;
    while ( (inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x00);
    if (max==0x0) keyboard_panic(00);

    /* Wait for data */
    max=0xffff;
    while ( ((inb(0x64) & 0x01) == 0) && (--max>0) ) outb(0x80, 0x01);
    if (max==0x0) keyboard_panic(01);

    /* read self-test result, 0x55 should be returned from 0x60 */
    if ((inb(0x60) != 0x55)){
        keyboard_panic(991);
    }

    /* send cmd = 0xAB, keyboard interface test */
    outb(0x64,0xab);

    /* Wait until buffer is empty */
    max=0xffff;
    while ((inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x10);
    if (max==0x0) keyboard_panic(10);

    /* Wait for data */
    max=0xffff;
    while ( ((inb(0x64) & 0x01) == 0) && (--max>0) ) outb(0x80, 0x11);
    if (max==0x0) keyboard_panic(11);

    /* read keyboard interface test result, */
    /* 0x00 should be returned form 0x60 */
    if ((inb(0x60) != 0x00)) {
        keyboard_panic(992);
    }

    /* Enable Keyboard clock */
    outb(0x64,0xae);
    outb(0x64,0xa8);

    /* ------------------- keyboard side ------------------------*/
    /* reset kerboard and self test  (keyboard side) */
    outb(0x60, 0xff);

    /* Wait until buffer is empty */
    max=0xffff;
    while ((inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x20);
    if (max==0x0) keyboard_panic(20);

    /* Wait for data */
    max=0xffff;
    while ( ((inb(0x64) & 0x01) == 0) && (--max>0) ) outb(0x80, 0x21);
    if (max==0x0) keyboard_panic(21);

    /* keyboard should return ACK */
    if ((inb(0x60) != 0xfa)) {
        keyboard_panic(993);
    }

    /* Wait for data */
    max=0xffff;
    while ( ((inb(0x64) & 0x01) == 0) && (--max>0) ) outb(0x80, 0x31);
    if (max==0x0) keyboard_panic(31);

    if ((inb(0x60) != 0xaa)) {
        keyboard_panic(994);
    }

    /* Disable keyboard */
    outb(0x60, 0xf5);

    /* Wait until buffer is empty */
    max=0xffff;
    while ((inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x40);
    if (max==0x0) keyboard_panic(40);

    /* Wait for data */
    max=0xffff;
    while ( ((inb(0x64) & 0x01) == 0) && (--max>0) ) outb(0x80, 0x41);
    if (max==0x0) keyboard_panic(41);

    /* keyboard should return ACK */
    if ((inb(0x60) != 0xfa)) {
        keyboard_panic(995);
    }

    /* Write Keyboard Mode */
    outb(0x64, 0x60);

    /* Wait until buffer is empty */
    max=0xffff;
    while ((inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x50);
    if (max==0x0) keyboard_panic(50);

    /* send cmd: scan code convert, disable mouse, enable IRQ 1 */
    outb(0x60, 0x61);

    /* Wait until buffer is empty */
    max=0xffff;
    while ((inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x60);
    if (max==0x0) keyboard_panic(60);

    /* Enable keyboard */
    outb(0x60, 0xf4);

    /* Wait until buffer is empty */
    max=0xffff;
    while ((inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x70);
    if (max==0x0) keyboard_panic(70);

    /* Wait for data */
    max=0xffff;
    while ( ((inb(0x64) & 0x01) == 0) && (--max>0) ) outb(0x80, 0x71);
    if (max==0x0) keyboard_panic(70);

    /* keyboard should return ACK */
    if ((inb(0x60) != 0xfa)) {
        keyboard_panic(996);
    }

    outb(0x80, 0x77);
}

//--------------------------------------------------------------------------
// keyboard_panic
//--------------------------------------------------------------------------
  void
keyboard_panic(status)
  Bit16u status;
{
  // If you're getting a 993 keyboard panic here, 
  // please see the comment in keyboard_init
  
  BX_PANIC("Keyboard error:%u\n",status);
}

//--------------------------------------------------------------------------
// machine_reset
//--------------------------------------------------------------------------
  void
machine_reset()
{
  /* Frob the keyboard reset line to reset the processor */
  outb(0x64, 0x60); /* Map the flags register at data port (0x60) */
  outb(0x60, 0x14); /* Set the flags to system|disable */
  outb(0x64, 0xfe); /* Pulse output 0 (system reset) low */
  BX_PANIC("Couldn't reset the machine\n");
}

//--------------------------------------------------------------------------
// clobber_entry_point
//    Because PV drivers in HVM guests detach some of the emulated devices, 
//    it is not safe to do a soft reboot by just dropping to real mode and
//    jumping at ffff:0000. -- the boot drives might have disappeared!
//    This rather foul function overwrites(!) the BIOS entry point 
//    to point at machine-reset, which will cause the Xen tools to
//    rebuild the whole machine from scratch.
//--------------------------------------------------------------------------
  void 
clobber_entry_point() 
{
    /* The instruction at the entry point is one byte (0xea) for the
     * jump opcode, then two bytes of address, then two of segment. 
     * Overwrite the address bytes.*/
    write_word(0xffff, 0x0001, machine_reset); 
}


//--------------------------------------------------------------------------
// shutdown_status_panic
//   called when the shutdown statsu is not implemented, displays the status
//--------------------------------------------------------------------------
  void
shutdown_status_panic(status)
  Bit16u status;
{
  BX_PANIC("Unimplemented shutdown status: %02x\n",(Bit8u)status);
}

//--------------------------------------------------------------------------
// print_bios_banner
//   displays a the bios version
//--------------------------------------------------------------------------
void
print_bios_banner()
{
  printf(BX_APPNAME" BIOS, %d cpu%s, ", BX_SMP_PROCESSORS, BX_SMP_PROCESSORS>1?"s":"");
  printf("%s %s\n", bios_cvs_version_string, bios_date_string);
#if BX_TCGBIOS
  printf("TCG-enabled BIOS.\n");
#endif
  printf("\n");
}


//--------------------------------------------------------------------------
// BIOS Boot Specification 1.0.1 compatibility
//
// Very basic support for the BIOS Boot Specification, which allows expansion 
// ROMs to register themselves as boot devices, instead of just stealing the 
// INT 19h boot vector.
// 
// This is a hack: to do it properly requires a proper PnP BIOS and we aren't
// one; we just lie to the option ROMs to make them behave correctly. 
// We also don't support letting option ROMs register as bootable disk 
// drives (BCVs), only as bootable devices (BEVs). 
//
// http://www.phoenix.com/en/Customer+Services/White+Papers-Specs/pc+industry+specifications.htm
//--------------------------------------------------------------------------

/* 256 bytes at 0x9ff00 -- 0x9ffff is used for the IPL boot table. */
#define IPL_SEG              0x9ff0
#define IPL_TABLE_OFFSET     0x0000
#define IPL_TABLE_ENTRIES    8
#define IPL_COUNT_OFFSET     0x0080  /* u16: number of valid table entries */
#define IPL_SEQUENCE_OFFSET  0x0082  /* u16: next boot device */

struct ipl_entry {
  Bit16u type;
  Bit16u flags;
  Bit32u vector;
  Bit32u description;
  Bit32u reserved;
};

static void 
init_boot_vectors() 
{
  struct ipl_entry e; 
  Bit16u count = 0;
  Bit16u ss = get_SS();

  /* Clear out the IPL table. */
  memsetb(IPL_SEG, IPL_TABLE_OFFSET, 0, 0xff);

  /* Floppy drive */
  e.type = 1; e.flags = 0; e.vector = 0; e.description = 0; e.reserved = 0;
  memcpyb(IPL_SEG, IPL_TABLE_OFFSET + count * sizeof (e), ss, &e, sizeof (e));
  count++;

  /* First HDD */
  e.type = 2; e.flags = 0; e.vector = 0; e.description = 0; e.reserved = 0;
  memcpyb(IPL_SEG, IPL_TABLE_OFFSET + count * sizeof (e), ss, &e, sizeof (e));
  count++;

#if BX_ELTORITO_BOOT
  /* CDROM */