void piix_bus_master_write(uint16_t port, uint8_t val, void *priv)
{
int channel = (port & 8) ? 1 : 0;
// pclog("PIIX Bus Master write %04X %02X %04x:%08x\n", port, val, CS, pc);
switch (port & 7)
{
case 0:
if ((val & 1) && !(piix_busmaster[channel].command & 1)) /*Start*/
{
piix_busmaster[channel].ptr_cur = piix_busmaster[channel].ptr;
piix_bus_master_next_addr(channel);
piix_busmaster[channel].status |= 1;
}
if (!(val & 1) && (piix_busmaster[channel].command & 1)) /*Stop*/
piix_busmaster[channel].status &= ~1;
piix_busmaster[channel].command = val;
break;
case 2:
piix_busmaster[channel].status = (val & 0x60) | ((piix_busmaster[channel].status & ~val) & 6) | (piix_busmaster[channel].status & 1);
break;
case 4:
piix_busmaster[channel].ptr = (piix_busmaster[channel].ptr & 0xffffff00) | val;
break;
case 5:
piix_busmaster[channel].ptr = (piix_busmaster[channel].ptr & 0xffff00ff) | (val << 8);
break;
case 6:
piix_busmaster[channel].ptr = (piix_busmaster[channel].ptr & 0xff00ffff) | (val << 16);
break;
case 7:
piix_busmaster[channel].ptr = (piix_busmaster[channel].ptr & 0x00ffffff) | (val << 24);
break;
}
}
int piix_bus_master_sector_read(int channel, uint8_t *data)
{
int transferred = 0;
if (!(piix_busmaster[channel].status & 1))
return 1; /*DMA disabled*/
while (transferred < 512)
{
if (piix_busmaster[channel].count < (512 - transferred) && piix_busmaster[channel].eot)
fatal("DMA on channel %i - Read count less than 512! Addr %08X Count %04X EOT %i\n", channel, piix_busmaster[channel].addr, piix_busmaster[channel].count, piix_busmaster[channel].eot);
mem_invalidate_range(piix_busmaster[channel].addr, piix_busmaster[channel].addr+511);
if (piix_busmaster[channel].count < (512 - transferred))
{
// pclog("Transferring smaller - %i bytes\n", piix_busmaster[channel].count);
memcpy(&ram[piix_busmaster[channel].addr], data + transferred, piix_busmaster[channel].count);
transferred += piix_busmaster[channel].count;
piix_busmaster[channel].addr += piix_busmaster[channel].count;
piix_busmaster[channel].addr %= (mem_size * 1024);
piix_busmaster[channel].count = 0;
}
else
{
// pclog("Transferring larger - %i bytes\n", 512 - transferred);
memcpy(&ram[piix_busmaster[channel].addr], data + transferred, 512 - transferred);
piix_busmaster[channel].addr += (512 - transferred);
piix_busmaster[channel].count -= (512 - transferred);
transferred += (512 - transferred);
}
// pclog("DMA on channel %i - Addr %08X Count %04X EOT %i\n", channel, piix_busmaster[channel].addr, piix_busmaster[channel].count, piix_busmaster[channel].eot);
if (!piix_busmaster[channel].count)
{
// pclog("DMA on channel %i - block over\n", channel);
if (piix_busmaster[channel].eot) /*End of transfer?*/
{
// pclog("DMA on channel %i - transfer over\n", channel);
piix_busmaster[channel].status &= ~1;
}
else
piix_bus_master_next_addr(channel);
}
}
return 0;
}