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Code: Select all

static void reboot(void)
{
   unsigned temp;

   disable();
/* flush the keyboard controller */
   do
   {
      temp = inportb(0x64);
      if((temp & 0x01) != 0)
      {
         (void)inportb(0x60);
         continue;
      }
   } while((temp & 0x02) != 0);
/* pulse the CPU reset line */
   outportb(0x64, 0xFE);
/* ...and if that didn't work, just halt */
   while(1);
/* nothing */
}

Code: Select all

void reboot() 
{
    volatile unsigned char good = 0x02;
    while ((good & 0x02) != 0)
        good = inport(0x64);
    outport(0x64, 0xFE);
    frz();
}

Code: Select all

typedef unsigned char uchar;
typedef uchar byte;

#define bit(n) (1<<(n)) /* Set to 1 bit n */
#define halt() asm volatile ("HLT") /* halt cpu */
#define disable() asm volatile ("CLI") /* disable interrupts */

/* keyboard interface IO port: data and control
   READ:   status port
   WRITE:   control register */
#define KBRD_INTRFC 0x64

/* keyboard interface bits */
#define KBRD_KDATA bit(0) /* keyboard data is (not) in buffer (bit 0) */
#define KBRD_UDATA bit(1) /* user data is (not) in buffer (bit 1) */

#define KBRD_IO 0x60 /* keyboard IO port */
#define KBRD_RESET 0xFE /* reset CPU command */

void reboot()
{
   byte temp;
   
   disable(); /* disable all interrupts */
   do /* empty user data in buffer */
   {
      temp = inb(KBRD_INTRFC);
      if ((temp & KBRD_KDATA) != 0)
         inb(KBRD_IO); /* empty keyboard data in buffer */
   } while ((temp & KBRD_UDATA) != 0);
   
   outb(KBRD_INTRFC, KBRD_RESET); /* pulse CPU reset line */
   halt(); /* if that didn't work, halt the CPU */
}

Code: Select all

KEYBOARD_BUSY     equ 0x02

_reset_pc:
                push ebp
                mov ebp,esp
                push eax

               cli

               call _wait_keyboard

               mov al,0xFE     ;send command to read output port to keyboard
               out 0x64,al

                sti
                pop eax
                mov esp,ebp
                pop ebp
                ret

_wait_keyboard:
               push eax
.wait:
               in al,0x64       ;wait for keyboard to be ready for next command
               test al,KEYBOARD_BUSY
               jnz .wait

               pop eax
               ret