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Code: Select all

int waituntilbusy(unsigned int base)
{
    unsigned int maxtry = 300000;
	unsigned char r;

  while(((r = inb(base + 0x07)) &  0x80) || !(r & 0x40))
       {
        maxtry--;
        if (maxtry == 0)
        {
            puts("Error: read time-out.\n");
            return 0;
        }
    }

 return 1;
}

int GetSector(unsigned char ide, unsigned long drive, unsigned long sector)
{
    unsigned char buffer[512];
    unsigned int idx;
    unsigned short tmpword;
    unsigned short base;

    if (ide == 0)
        base = 0x1F0;
    else
        if (ide == 1)
            base = 0x170;
        else
            return 0;

    // first set the read parameters
    outb(base + 1, 0x0); // reset the error flag
    outb(base + 2, 0x1); // read 1 sector
    outb(base + 3, (unsigned char)sector); // first address byte
    outb(base + 4, (unsigned char)(sector >> 8)); // second address byte
    outb(base + 5, (unsigned char)(sector >> 16)); // third address byte

    outb(base + 6, 0xE0 | (drive << 4) | ((sector >> 24) & 0x0F)); // select drive
    outb(base + 7, 0x20); // read with retry

    if (!waituntilbusy(base))
        return 0;


    for (idx = 0; idx < 256; idx++)
    {
        tmpword = inw(base); // read a word
        buffer[idx * 2] = (unsigned char)tmpword;
        buffer[idx * 2 + 1] = (unsigned char)(tmpword >> 8);
    }

    for (idx = 0; idx < 512; idx++)
        putch(buffer[idx]);

    return 1;
}

Code: Select all

void nanodelay(unsigned int ns)
{
   //Approx delay
   ns *= 4;
   while(ns > 0) ns--;
}

int waituntilbusy(unsigned int base)
{
   unsigned int maxtry = 300000;
   unsigned char r;
   
   nanodelay(400);

   r = inb(base + 0x07);
   while((r & 0x88) != 0x08)
   {
      maxtry--;
      if (maxtry <= 0)
      {
         puts("Error: read time-out.\n");
         return 0;
      }
      r = inb(base + 0x07);
   }
   return 1;
}