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Bochs/bochs/iodev/dma.cc

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// Copyright (C) 2001 MandrakeSoft S.A.
//
// MandrakeSoft S.A.
// 43, rue d'Aboukir
// 75002 Paris - France
// http://www.linux-mandrake.com/
// http://www.mandrakesoft.com/
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#include "bochs.h"
#define LOG_THIS bx_dma.
#define DMA_MODE_DEMAND 0
#define DMA_MODE_SINGLE 1
#define DMA_MODE_BLOCK 2
#define DMA_MODE_CASCADE 3
bx_dma_c bx_dma;
#if BX_USE_DMA_SMF
#define this (&bx_dma)
#endif
bx_dma_c::bx_dma_c(void)
{
setprefix("DMA");
settype(DMALOG);
BX_DEBUG(("Init."));
}
bx_dma_c::~bx_dma_c(void)
{
BX_DEBUG(("Exit."));
}
void
bx_dma_c::init(bx_devices_c *d)
{
unsigned c;
BX_DMA_THIS devices = d;
/* 8237 DMA controller */
// 0000..000F
unsigned i;
for (i=0x0000; i<=0x000F; i++) {
BX_DMA_THIS devices->register_io_read_handler(this, read_handler,
i, "DMA controller");
BX_DMA_THIS devices->register_io_write_handler(this, write_handler,
i, "DMA controller");
}
// 00081..008D
for (i=0x0081; i<=0x008D; i++) {
BX_DMA_THIS devices->register_io_read_handler(this, read_handler,
i, "DMA controller");
BX_DMA_THIS devices->register_io_write_handler(this, write_handler,
i, "DMA controller");
}
// 0008F..008F
for (i=0x008F; i<=0x008F; i++) {
BX_DMA_THIS devices->register_io_read_handler(this, read_handler,
i, "DMA controller");
BX_DMA_THIS devices->register_io_write_handler(this, write_handler,
i, "DMA controller");
}
// 000C0..00DE
for (i=0x00C0; i<=0x00DE; i++) {
BX_DMA_THIS devices->register_io_read_handler(this, read_handler,
i, "DMA controller");
BX_DMA_THIS devices->register_io_write_handler(this, write_handler,
i, "DMA controller");
}
BX_DMA_THIS s.mask[0] = 1; // channel 0 masked
BX_DMA_THIS s.mask[1] = 1; // channel 1 masked
BX_DMA_THIS s.mask[2] = 1; // channel 2 masked
BX_DMA_THIS s.mask[3] = 1; // channel 3 masked
BX_DMA_THIS s.flip_flop = 0; /* cleared */
BX_DMA_THIS s.status_reg = 0; // no requests, no terminal counts reached
for (c=0; c<4; c++) {
BX_DMA_THIS s.chan[c].mode.mode_type = 0; // demand mode
BX_DMA_THIS s.chan[c].mode.address_decrement = 0; // address increment
BX_DMA_THIS s.chan[c].mode.autoinit_enable = 0; // autoinit disable
BX_DMA_THIS s.chan[c].mode.transfer_type = 0; // verify
BX_DMA_THIS s.chan[c].base_address = 0;
BX_DMA_THIS s.chan[c].current_address = 0;
BX_DMA_THIS s.chan[c].base_count = 0;
BX_DMA_THIS s.chan[c].current_count = 0;
BX_DMA_THIS s.chan[c].page_reg = 0;
}
}
// index to find channel from register number (only [0],[1],[2],[6] used)
Bit8u channelindex[7] = {2, 3, 1, 0, 0, 0, 0};
// static IO port read callback handler
// redirects to non-static class handler to avoid virtual functions
Bit32u
bx_dma_c::read_handler(void *this_ptr, Bit32u address, unsigned io_len)
{
#if !BX_USE_DMA_SMF
bx_dma_c *class_ptr = (bx_dma_c *) this_ptr;
return( class_ptr->read(address, io_len) );
}
/* 8237 DMA controller */
Bit32u
bx_dma_c::read( Bit32u address, unsigned io_len)
{
#else
UNUSED(this_ptr);
#endif // !BX_USE_DMA_SMF
Bit8u retval;
Bit8u channel;
if (io_len > 1) {
BX_ERROR(("io read from address %08x, len=%u",
(unsigned) address, (unsigned) io_len));
return 0xff;
}
BX_DEBUG(("read addr=%04x", (unsigned) address));
#if BX_DMA_FLOPPY_IO < 1
/* if we're not supporting DMA/floppy IO just return a bogus value */
return(0xff);
#endif
switch (address) {
case 0x00: /* DMA-1 current address, channel 0 */
case 0x02: /* DMA-1 current address, channel 1 */
case 0x04: /* DMA-1 current address, channel 2 */
case 0x06: /* DMA-1 current address, channel 3 */
channel = address >> 1;
if (BX_DMA_THIS s.flip_flop==0) {
BX_DMA_THIS s.flip_flop = !BX_DMA_THIS s.flip_flop;
return(BX_DMA_THIS s.chan[channel].current_address & 0xff);
}
else {
BX_DMA_THIS s.flip_flop = !BX_DMA_THIS s.flip_flop;
return(BX_DMA_THIS s.chan[channel].current_address >> 8);
}
case 0x01: /* DMA-1 current count, channel 0 */
case 0x03: /* DMA-1 current count, channel 1 */
case 0x05: /* DMA-1 current count, channel 2 */
case 0x07: /* DMA-1 current count, channel 3 */
channel = address >> 1;
if (BX_DMA_THIS s.flip_flop==0) {
BX_DMA_THIS s.flip_flop = !BX_DMA_THIS s.flip_flop;
return(BX_DMA_THIS s.chan[channel].current_count & 0xff);
}
else {
BX_DMA_THIS s.flip_flop = !BX_DMA_THIS s.flip_flop;
return(BX_DMA_THIS s.chan[channel].current_count >> 8);
}
case 0x08: // DMA-1 Status Register
// bit 7: 1 = channel 3 request
// bit 6: 1 = channel 2 request
// bit 5: 1 = channel 1 request
// bit 4: 1 = channel 0 request
// bit 3: 1 = channel 3 has reached terminal count
// bit 2: 1 = channel 2 has reached terminal count
// bit 1: 1 = channel 1 has reached terminal count
// bit 0: 1 = channel 0 has reached terminal count
// reading this register clears lower 4 bits (hold flags)
retval = BX_DMA_THIS s.status_reg;
BX_DMA_THIS s.status_reg &= 0xf0;
return(retval);
break;
case 0x0d: // dma-1: temporary register
BX_PANIC(("dma-1: read of temporary register"));
// Note: write to 0x0D clears temporary register
return(0);
break;
case 0x0081: // DMA-1 page register, channel 2
case 0x0082: // DMA-1 page register, channel 3
case 0x0083: // DMA-1 page register, channel 1
case 0x0087: // DMA-1 page register, channel 0
channel = channelindex[address - 0x81];
return( BX_DMA_THIS s.chan[channel].page_reg );
case 0x0084: // ???
return(0);
case 0x0089: // DMA-2 page register, channel 6
case 0x008a: // DMA-2 page register, channel 7
case 0x008b: // DMA-2 page register, channel 5
case 0x008f: // DMA-2 page register, channel 4
channel = channelindex[address - 0x89] + 4;
BX_ERROR(("read: unsupported address=%04x (channel %d)",
(unsigned) address, channel));
return( 0x00 );
case 0x00c0:
case 0x00c2:
case 0x00c4:
case 0x00c6:
case 0x00c8:
case 0x00ca:
case 0x00cc:
case 0x00ce:
case 0x00d0:
case 0x00d2:
case 0x00d4:
case 0x00d6:
case 0x00d8:
case 0x00da:
case 0x00dc:
case 0x00de:
BX_ERROR(("read: unsupported address=%04x", (unsigned) address));
return(0x0000);
break;
default:
BX_PANIC(("read: unsupported address=%04x", (unsigned) address));
return(0);
}
}
// static IO port write callback handler
// redirects to non-static class handler to avoid virtual functions
void
bx_dma_c::write_handler(void *this_ptr, Bit32u address, Bit32u value, unsigned io_len)
{
#if !BX_USE_DMA_SMF
bx_dma_c *class_ptr = (bx_dma_c *) this_ptr;
class_ptr->write(address, value, io_len);
}
/* 8237 DMA controller */
void
bx_dma_c::write(Bit32u address, Bit32u value, unsigned io_len)
{
#else
UNUSED(this_ptr);
#endif // !BX_USE_DMA_SMF
Bit8u set_mask_bit;
Bit8u channel;
if (io_len > 1) {
if ( (io_len == 2) && (address == 0x0b) ) {
#if BX_USE_DMA_SMF
BX_DMA_THIS write_handler(NULL, address, value & 0xff, 1);
BX_DMA_THIS write_handler(NULL, address+1, value >> 8, 1);
#else
BX_DMA_THIS write(address, value & 0xff, 1);
BX_DMA_THIS write(address+1, value >> 8, 1);
#endif
return;
}
BX_ERROR(("io write to address %08x, len=%u",
(unsigned) address, (unsigned) io_len));
return;
}
BX_DEBUG(("dma: write: address=%04x value=%02x",
(unsigned) address, (unsigned) value));
#if BX_DMA_FLOPPY_IO < 1
/* if we're not supporting DMA/floppy IO just return */
return;
#endif
switch (address) {
case 0x00:
case 0x02:
case 0x04:
case 0x06:
channel = address >> 1;
BX_DEBUG((" DMA-1 base and current address, channel %d", channel));
if (BX_DMA_THIS s.flip_flop==0) { /* 1st byte */
BX_DMA_THIS s.chan[channel].base_address = value;
BX_DMA_THIS s.chan[channel].current_address = value;
}
else { /* 2nd byte */
BX_DMA_THIS s.chan[channel].base_address |= (value << 8);
BX_DMA_THIS s.chan[channel].current_address |= (value << 8);
BX_DEBUG((" base = %04x",
(unsigned) BX_DMA_THIS s.chan[channel].base_address));
BX_DEBUG((" curr = %04x",
(unsigned) BX_DMA_THIS s.chan[channel].current_address));
}
BX_DMA_THIS s.flip_flop = !BX_DMA_THIS s.flip_flop;
return;
break;
case 0x01:
case 0x03:
case 0x05:
case 0x07:
channel = address >> 1;
BX_DEBUG((" DMA-1 base and current count, channel %d", channel));
if (BX_DMA_THIS s.flip_flop==0) { /* 1st byte */
BX_DMA_THIS s.chan[channel].base_count = value;
BX_DMA_THIS s.chan[channel].current_count = value;
}
else { /* 2nd byte */
BX_DMA_THIS s.chan[channel].base_count |= (value << 8);
BX_DMA_THIS s.chan[channel].current_count |= (value << 8);
BX_DEBUG((" base = %04x",
(unsigned) BX_DMA_THIS s.chan[channel].base_count));
BX_DEBUG((" curr = %04x",
(unsigned) BX_DMA_THIS s.chan[channel].current_count));
}
BX_DMA_THIS s.flip_flop = !BX_DMA_THIS s.flip_flop;
return;
break;
case 0x08: /* DMA-1: command register */
if (value != 0x04)
BX_ERROR(("DMA: write to 0008: value(%02xh) not 04h",
(unsigned) value));
BX_DMA_THIS s.command_reg = value;
return;
break;
case 0x09: // DMA-1: request register
BX_ERROR(("DMA-1: write to request register (%02x)", (unsigned) value));
// note: write to 0x0d clears this register
if (value & 0x04) {
// set request bit
}
else {
Bit8u channel;
// clear request bit
channel = value & 0x03;
BX_DMA_THIS s.status_reg &= ~(1 << (channel+4));
BX_DEBUG(("dma-1: cleared request bit for channel %u", (unsigned) channel));
}
return;
break;
case 0x0a:
set_mask_bit = value & 0x04;
channel = value & 0x03;
BX_DMA_THIS s.mask[channel] = (set_mask_bit > 0);
BX_DEBUG(("DMA1: set_mask_bit=%u, channel=%u, mask now=%02xh",
(unsigned) set_mask_bit, (unsigned) channel, (unsigned) BX_DMA_THIS s.mask[channel]));
return;
break;
case 0x0b: /* dma-1 mode register */
channel = value & 0x03;
BX_DMA_THIS s.chan[channel].mode.mode_type = (value >> 6) & 0x03;
BX_DMA_THIS s.chan[channel].mode.address_decrement = (value >> 5) & 0x01;
BX_DMA_THIS s.chan[channel].mode.autoinit_enable = (value >> 4) & 0x01;
BX_DMA_THIS s.chan[channel].mode.transfer_type = (value >> 2) & 0x03;
//BX_DEBUG(("DMA1: mode register[%u] = %02x",
//(unsigned) channel, (unsigned) value));
BX_DEBUG(("DMA1: mode register[%u] = %02x",
(unsigned) channel, (unsigned) value));
return;
break;
case 0x0c: /* dma-1 clear byte flip/flop */
BX_DEBUG(("DMA1: clear flip/flop"));
BX_DMA_THIS s.flip_flop = 0;
return;
break;
case 0x0d: // dma-1: master disable
/* ??? */
BX_DEBUG(("master disable"));
// writing any value to this port resets DMA controller 1
// same action as a hardware reset
// mask register is set (chan 0..3 disabled)
// command, status, request, temporary, and byte flip-flop are all cleared
BX_DMA_THIS s.mask[0] = 1;
BX_DMA_THIS s.mask[1] = 1;
BX_DMA_THIS s.mask[2] = 1;
BX_DMA_THIS s.mask[3] = 1;
BX_DMA_THIS s.command_reg = 0;
BX_DMA_THIS s.status_reg = 0;
BX_DMA_THIS s.request_reg = 0;
BX_DMA_THIS s.temporary_reg = 0;
BX_DMA_THIS s.flip_flop = 0;
return;
break;
case 0x0e: // dma-1: clear mask register
BX_DEBUG(("dma-1: clear mask register"));
BX_DMA_THIS s.mask[0] = 0;
BX_DMA_THIS s.mask[1] = 0;
BX_DMA_THIS s.mask[2] = 0;
BX_DMA_THIS s.mask[3] = 0;
return;
break;
case 0x0f: // dma-1: write all mask bits
BX_DEBUG(("dma-1: write all mask bits"));
BX_DMA_THIS s.mask[0] = value & 0x01; value >>= 1;
BX_DMA_THIS s.mask[1] = value & 0x01; value >>= 1;
BX_DMA_THIS s.mask[2] = value & 0x01; value >>= 1;
BX_DMA_THIS s.mask[3] = value & 0x01;
return;
break;
case 0x81: /* dma page register, channel 2 */
case 0x82: /* dma page register, channel 3 */
case 0x83: /* dma page register, channel 1 */
case 0x87: /* dma page register, channel 0 */
/* address bits A16-A23 for DMA channel */
channel = channelindex[address - 0x81];
BX_DMA_THIS s.chan[channel].page_reg = value;
BX_DEBUG(("DMA1: page register %d = %02x", channel, (unsigned) value));
return;
break;
case 0x0084: // ???
return;
break;
//case 0xd0: /* DMA-2 command register */
// if (value != 0x04)
// BX_DEBUG(("DMA2: write command register: value(%02xh)!=04h",
// (unsigned) value));
// return;
// break;
case 0x00c0:
case 0x00c2:
case 0x00c4:
case 0x00c6:
case 0x00c8:
case 0x00ca:
case 0x00cc:
case 0x00ce:
case 0x00d0:
case 0x00d2:
case 0x00d4:
case 0x00d6:
case 0x00d8:
case 0x00da:
case 0x00dc:
case 0x00de:
BX_DEBUG(("DMA(ignored): write: %04xh = %04xh",
(unsigned) address, (unsigned) value));
return;
break;
default:
BX_ERROR(("DMA(ignored): write: %04xh = %02xh",
(unsigned) address, (unsigned) value));
}
}
void
bx_dma_c::DRQ(unsigned channel, Boolean val)
{
Bit32u dma_base, dma_roof;
#if BX_SUPPORT_SB16
if ( (channel != 2) && (channel != (unsigned) BX_SB16_DMAL) )
BX_PANIC(("bx_dma_c::DRQ(): channel %d != 2 or %d (SB16) (",
channel, BX_SB16_DMAL));
#else
if ( channel != 2 )
BX_PANIC(("bx_dma_c::DRQ(): channel %d != 2",
channel));
#endif
if (!val) {
//BX_DEBUG(("bx_dma_c::DRQ(): val == 0"));
// clear bit in status reg
// deassert HRQ if not pending DRQ's ?
// etc.
BX_DMA_THIS s.status_reg &= ~(1 << (channel+4));
return;
}
#if 0
BX_INFO(("BX_DMA_THIS s.mask[2]: %02x", (unsigned) BX_DMA_THIS s.mask[2]));
BX_INFO(("BX_DMA_THIS s.flip_flop: %u", (unsigned) BX_DMA_THIS s.flip_flop));
BX_INFO(("BX_DMA_THIS s.status_reg: %02x", (unsigned) BX_DMA_THIS s.status_reg));
BX_INFO(("mode_type: %02x", (unsigned) BX_DMA_THIS s.chan[channel].mode.mode_type));
BX_INFO(("address_decrement: %02x", (unsigned) BX_DMA_THIS s.chan[channel].mode.address_decrement));
BX_INFO(("autoinit_enable: %02x", (unsigned) BX_DMA_THIS s.chan[channel].mode.autoinit_enable));
BX_INFO(("transfer_type: %02x", (unsigned) BX_DMA_THIS s.chan[channel].mode.transfer_type));
BX_INFO((".base_address: %04x", (unsigned) BX_DMA_THIS s.chan[channel].base_address));
BX_INFO((".current_address: %04x", (unsigned) BX_DMA_THIS s.chan[channel].current_address));
BX_INFO((".base_count: %04x", (unsigned) BX_DMA_THIS s.chan[channel].base_count));
BX_INFO((".current_count: %04x", (unsigned) BX_DMA_THIS s.chan[channel].current_count));
BX_INFO((".page_reg: %02x", (unsigned) BX_DMA_THIS s.chan[channel].page_reg));
#endif
BX_DMA_THIS s.status_reg |= (1 << (channel+4));
// if (BX_DMA_THIS s.mask[channel])
// BX_PANIC(("bx_dma_c::DRQ(): BX_DMA_THIS s.mask[] is set"));
if ( (BX_DMA_THIS s.chan[channel].mode.mode_type != DMA_MODE_SINGLE) &&
(BX_DMA_THIS s.chan[channel].mode.mode_type != DMA_MODE_DEMAND) )
BX_PANIC(("bx_dma_c::DRQ: mode_type(%02x) not handled",
(unsigned) BX_DMA_THIS s.chan[channel].mode.mode_type));
if (BX_DMA_THIS s.chan[channel].mode.address_decrement != 0)
BX_PANIC(("bx_dma_c::DRQ: address_decrement != 0"));
//if (BX_DMA_THIS s.chan[channel].mode.autoinit_enable != 0)
// BX_PANIC(("bx_dma_c::DRQ: autoinit_enable != 0"));
dma_base = (BX_DMA_THIS s.chan[channel].page_reg << 16) | BX_DMA_THIS s.chan[channel].base_address;
dma_roof = dma_base + BX_DMA_THIS s.chan[channel].base_count;
if ( (dma_base & 0xffff0000) != (dma_roof & 0xffff0000) ) {
BX_INFO(("dma_base = %08x", (unsigned) dma_base));
BX_INFO(("dma_base_count = %08x", (unsigned) BX_DMA_THIS s.chan[channel].base_count));
BX_INFO(("dma_roof = %08x", (unsigned) dma_roof));
BX_PANIC(("request outside 64k boundary"));
}
//BX_DEBUG(("DRQ set up for single mode, increment, auto-init disabled, write"));
// should check mask register VS DREQ's in status register here?
// assert Hold ReQuest line to CPU
bx_pc_system.set_HRQ(1);
}
void
bx_dma_c::raise_HLDA(bx_pc_system_c *pc_sys)
{
unsigned channel;
Bit32u phy_addr;
Boolean count_expired = 0;
// find highest priority channel
for (channel=0; channel<4; channel++) {
if ( (BX_DMA_THIS s.status_reg & (1 << (channel+4))) &&
(BX_DMA_THIS s.mask[channel]==0) ) {
break;
}
}
if (channel >= 4) {
// don't panic, just wait till they're unmasked
// BX_PANIC(("hlda: no unmasked requests"));
return;
}
//BX_DEBUG(("hlda: OK in response to DRQ(%u)", (unsigned) channel));
phy_addr = (BX_DMA_THIS s.chan[channel].page_reg << 16) |
BX_DMA_THIS s.chan[channel].current_address;
bx_pc_system.set_DACK(channel, 1);
// check for expiration of count, so we can signal TC and DACK(n)
// at the same time.
if (BX_DMA_THIS s.chan[channel].mode.address_decrement==0) {
// address increment
BX_DMA_THIS s.chan[channel].current_address++;
BX_DMA_THIS s.chan[channel].current_count--;
if (BX_DMA_THIS s.chan[channel].current_count == 0xffff)
if (BX_DMA_THIS s.chan[channel].mode.autoinit_enable == 0) {
// count expired, done with transfer
// assert TC, deassert HRQ & DACK(n) lines
BX_DMA_THIS s.status_reg |= (1 << channel); // hold TC in status reg
bx_pc_system.set_TC(1);
count_expired = 1;
} else {
// count expired, but in autoinit mode
// reload count and base address
BX_DMA_THIS s.chan[channel].current_address =
BX_DMA_THIS s.chan[channel].base_address;
BX_DMA_THIS s.chan[channel].current_count =
BX_DMA_THIS s.chan[channel].base_count;
}
}
else {
// address decrement
BX_PANIC(("hlda: decrement not implemented"));
}
if (BX_DMA_THIS s.chan[channel].mode.transfer_type == 1) { // write
// xfer from I/O to Memory
pc_sys->dma_write8(phy_addr, channel);
}
else if (BX_DMA_THIS s.chan[channel].mode.transfer_type == 2) { // read
// xfer from Memory to I/O
pc_sys->dma_read8(phy_addr, channel);
}
else {
BX_PANIC(("hlda: transfer_type of %u not handled",
(unsigned) BX_DMA_THIS s.chan[channel].mode.transfer_type));
}
if (count_expired) {
bx_pc_system.set_TC(0); // clear TC, adapter card already notified
bx_pc_system.set_HRQ(0); // clear HRQ to CPU
bx_pc_system.set_DACK(channel, 0); // clear DACK to adapter card
}
}
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