1
0
Fork 0

Implemented 16-bit DMA support

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@1398
This commit is contained in:
Dean Beeler 2003-11-04 03:41:33 +00:00
parent 9d8d93a7dd
commit ed4d000c14
2 changed files with 513 additions and 251 deletions

View file

@ -20,11 +20,6 @@
Based the port handling from the bochs dma code.
*/
/*
TODO
Implement 16-bit dma
*/
#include <string.h>
#include "dosbox.h"
#include "mem.h"
@ -32,259 +27,193 @@
#include "dma.h"
#include "pic.h"
#define DMA_MODE_DEMAND 0
#define DMA_MODE_SINGLE 1
#define DMA_MODE_BLOCK 2
#define DMA_MODE_CASCADE 3
struct DMA_CHANNEL {
struct {
Bit8u mode_type;
bool address_decrement;
bool autoinit_enable;
Bit8u transfer_type;
} mode;
Bit16u base_address;
Bit16u base_count;
Bit16u current_address;
Bitu current_count;
Bit8u page;
bool masked;
PhysPt address;
bool addr_changed;
bool enabled;
DMA_EnableCallBack enable_callback;
};
DmaChannel *DmaChannels[8];
DmaController *DmaControllers[2];
struct DMA_CONTROLLER {
bool flipflop;
Bit8u status_reg;
Bit8u command_reg;
DMA_CHANNEL chan[4];
};
Bit16u DmaController::portRead(Bit32u port, bool eightbit) {
LOG_MSG("Reading DMA controller at %x", port);
return 0xffff;
}
static DMA_CONTROLLER dma[2];
void DMA_CheckEnabled(DMA_CHANNEL * chan);
void DMA_SetEnabled(DMA_CHANNEL * chan,bool enabled);
static Bit8u read_dma(Bit32u port) {
/* only use first dma for now */
DMA_CONTROLLER * cont=&dma[0];
DMA_CHANNEL * chan=&cont->chan[port>>1];
Bit8u ret;
switch (port) {
case 0x00:case 0x02:case 0x04:case 0x06:
if (cont->flipflop) {
ret=chan->current_address & 0xff;
} else {
ret=(chan->current_address>>8)&0xff;
}
cont->flipflop=!cont->flipflop;
break;
case 0x01:case 0x03:case 0x05:case 0x07:
if (cont->flipflop) {
ret=(Bit8u)((chan->current_count-1) & 0xff);
} else {
ret=(Bit8u)(((chan->current_count-1)>>8)&0xff);
}
cont->flipflop=!cont->flipflop;
break;
case 0x08: /* Read Status */
ret=cont->status_reg;
cont->status_reg&=~0xf; /* Clear lower 4 bits on read */
break;
case 0x0a:
case 0x0e:
/* Seem to return 0 on a real controller */
ret=0x0;
break;
default:
LOG(LOG_DMA,LOG_ERROR)("DMA:Unhandled read from %X",port);
void DmaController::portWrite(Bit32u port, Bit16u val, bool eightbit) {
bool found;
found = false;
if(port == ControllerPorts[ctrlnum][DMA_CLRMASKREG]) {
found = true;
flipflop = true;
// Disable DMA requests
// Clear command and status registers
}
// LOG_MSG("DMA Read port %x result %x",port,ret);
return ret;
}
static void write_dma(Bit32u port,Bit8u val) {
/* only use first dma for now */
DMA_CONTROLLER * cont=&dma[0];
DMA_CHANNEL * chan;
switch (port) {
case 0x00:case 0x02:case 0x04:case 0x06:
chan=&cont->chan[port>>1];
if (cont->flipflop) {
chan->base_address=(chan->base_address & 0xff00) | val;
} else {
chan->base_address=(chan->base_address & 0x00ff) | (val<<8);
}
cont->flipflop=!cont->flipflop;
chan->addr_changed=true;
break;
case 0x01:case 0x03:case 0x05:case 0x07:
chan=&cont->chan[port>>1];
if (cont->flipflop) {
chan->base_count=(chan->base_count & 0xff00) | val;
} else {
chan->base_count=(chan->base_count & 0x00ff) | (val<<8);
}
cont->flipflop=!cont->flipflop;
chan->addr_changed=true;
DMA_CheckEnabled(chan);
break;
case 0x08: /* Command Register */
if (val != 4) LOG(LOG_DMA,LOG_ERROR)("DMA1:Illegal command %2X",val);
cont->command_reg=val;
break;
case 0x09: /* Request Register */
if (val&4) {
/* Set Request bit */
Bitu channel = val & 0x03;
cont->status_reg |= (1 << (channel+4));
} else {
Bitu channel = val & 0x03;
cont->status_reg &= ~(1 << (channel+4));
}
break;
case 0x0a: /* single mask bit register */
chan=&cont->chan[val & 0x3];
if ((val & 4)>0) {
DMA_SetEnabled(chan,false);
chan->masked=(val & 4)>0; //Set it later
} else {
chan->masked=(val & 4)>0;
DMA_CheckEnabled(chan);
}
break;
case 0x0b: /* mode register */
chan=&cont->chan[val & 0x3];
chan->mode.mode_type = (val >> 6) & 0x03;
chan->mode.address_decrement = (val & 0x20) > 0;
chan->mode.autoinit_enable = (val & 0x10) > 0;
chan->mode.transfer_type = (val >> 2) & 0x03;
if (chan->mode.address_decrement) {
LOG(LOG_DMA,LOG_ERROR)("DMA:Address Decrease not supported yet");
}
DMA_CheckEnabled(chan);
break;
case 0x0c: /* Clear Flip/Flip */
cont->flipflop=true;
break;
default:
LOG(LOG_DMA,LOG_ERROR)("DMA:Unhandled write %X to %X",static_cast<Bit32u>(val),port);
};
};
void write_dma_page(Bit32u port,Bit8u val) {
Bitu channel;
switch (port) {
case 0x81: /* dma0 page register, channel 2 */
channel=2;break;
case 0x82: /* dma0 page register, channel 3 */
channel=3;break;
case 0x83: /* dma0 page register, channel 1 */
channel=1;break;
case 0x87: /* dma0 page register, channel 0 */
channel=0;break;
if(port == ControllerPorts[ctrlnum][DMA_SINGLEREG]) {
found = true;
int dmachan;
dmachan = (ctrlnum * 2) + (val & 0x3);
DmaChannels[dmachan]->masked = ((val & 0x4) == 0x4);
DmaChannels[dmachan]->Notify();
}
dma[0].chan[channel].page=val;
dma[0].chan[channel].addr_changed=true;
}
Bit8u read_dma_page(Bit32u port) {
Bitu channel;
switch (port) {
case 0x81: /* dma0 page register, channel 2 */
channel=2;break;
case 0x82: /* dma0 page register, channel 3 */
channel=3;break;
case 0x83: /* dma0 page register, channel 1 */
channel=1;break;
case 0x87: /* dma0 page register, channel 0 */
channel=0;break;
if(port == ControllerPorts[ctrlnum][DMA_WRITEALLREG]) {
found = true;
int dmachan,i,r;
dmachan = (ctrlnum * 2);
r = 0;
for(i=dmachan;i<dmachan+4;i++) {
DmaChannels[i]->masked = (((val >> r) & 0x1) == 0x1);
DmaChannels[i]->Notify();
r++;
}
}
return dma[0].chan[channel].page;
if(port == ControllerPorts[ctrlnum][DMA_CLEARREG]) {
found = true;
flipflop = true;
}
if(port == ControllerPorts[ctrlnum][DMA_MODEREG]) {
found = true;
int dmachan;
dmachan = (ctrlnum * 2) + (val & 0x3);
DmaChannels[dmachan]->trantype = (val >> 2) & 0x3;
DmaChannels[dmachan]->autoinit = ((val & 0x10) == 0x10);
DmaChannels[dmachan]->dir = ((val & 0x20) == 0x20);
DmaChannels[dmachan]->dmamode = (val >> 6) & 0x3;
DMA_CheckEnabled(DmaChannels[dmachan]);
}
if(!found) LOG_MSG("Write to DMA port %x with %x", port, val);
}
INLINE void ResetDMA8(DMA_CHANNEL * chan) {
chan->addr_changed=false;
chan->address=(chan->page << 16)+chan->base_address;
chan->current_count=chan->base_count+1;
chan->current_address=chan->base_address;
LOG(LOG_DMA,LOG_NORMAL)("Setup at address %X:%X count %X",chan->page<<12,chan->base_address,chan->current_count);
static Bit16u readDMAPorts(Bit32u port, bool eightbit) {
int i,j;
// Check for controller access
for(i=0;i<2;i++) {
for(j=0;j<7;j++) {
if(ControllerPorts[i][j] == port) {
return DmaControllers[i]->portRead(port, eightbit);
}
}
}
// Check for DMA access
for(i=0;i<8;i++) {
for(j=0;j<3;j++) {
if(ChannelPorts[j][i] == port) {
return DmaChannels[i]->portRead(port, eightbit);
}
}
}
LOG_MSG("Unmatched read port %x", port);
return 0xffff;
}
static void writeDMAPorts(Bit32u port, Bit16u val, bool eightbit) {
int i,j;
// Check for controller access
for(i=0;i<2;i++) {
for(j=0;j<7;j++) {
if(ControllerPorts[i][j] == port) {
DmaControllers[i]->portWrite(port,val,eightbit);
return;
}
}
}
// Check for DMA access
for(i=0;i<8;i++) {
for(j=0;j<3;j++) {
if(ChannelPorts[j][i] == port) {
DmaChannels[i]->portWrite(port,val,eightbit);
return;
}
}
}
LOG_MSG("Unmatched write port %x - val %x", port, val);
}
Bit8u read_dmaB(Bit32u port) { return (Bit8u)readDMAPorts(port,true); }
Bit16u read_dmaW(Bit32u port) { return readDMAPorts(port,false); }
void write_dmaB(Bit32u port,Bit8u val) { writeDMAPorts(port,val,true); }
void write_dmaW(Bit32u port,Bit16u val) { writeDMAPorts(port,val,false); }
// Deprecated DMA read/write routines -- Keep compatibility with Sound Blaster
Bitu DMA_8_Read(Bitu dmachan,Bit8u * buffer,Bitu count) {
DMA_CHANNEL * chan=&dma[0].chan[dmachan];
DmaChannel *chan=DmaChannels[dmachan];
if (chan->masked) return 0;
if (!count) return 0;
if (chan->addr_changed) ResetDMA8(chan);
if (chan->current_count>count) {
MEM_BlockRead(chan->address,buffer,count);
chan->address+=count;
chan->current_address+=count;
chan->current_count-=count;
if (chan->currcnt>count) {
MEM_BlockRead(chan->curraddr,buffer,count);
chan->curraddr+=count;
chan->current_addr+=count;
chan->currcnt-=count;
return count;
} else {
/* Copy remaining piece of first buffer */
MEM_BlockRead(chan->address,buffer,chan->current_count);
if (!chan->mode.autoinit_enable) {
/* Set the end of counter bit */
dma[0].status_reg|=(1 << dmachan);
count=chan->current_count;
chan->address+=count;
chan->current_count=0;
// Copy remaining piece of first buffer
MEM_BlockRead(chan->curraddr,buffer,chan->currcnt);
if (!chan->autoinit) {
// Set the end of counter bit
//dma[0].status_reg|=(1 << dmachan);
count=chan->currcnt;
chan->curraddr+=count;
chan->current_addr+=count;
chan->currcnt=0;
chan->enabled=false;
LOG(LOG_DMA,LOG_NORMAL)("8-bit Channel %d reached terminal count");
return count;
} else {
buffer+=chan->current_count;
Bitu left=count-(Bit16u)chan->current_count;
/* Autoinit reset the dma channel */
ResetDMA8(chan);
/* Copy the rest of the buffer */
MEM_BlockRead(chan->address,buffer,left);
chan->address+=left;
chan->current_address+=left;
chan->current_count-=left;
buffer+=chan->currcnt;
Bitu left=count-(Bit16u)chan->currcnt;
// Autoinit reset the dma channel
chan->reset();
// Copy the rest of the buffer
MEM_BlockRead(chan->curraddr,buffer,left);
chan->curraddr+=left;
chan->current_addr+=left;
chan->currcnt-=left;
return count;
}
}
}
Bitu DMA_8_Write(Bitu dmachan,Bit8u * buffer,Bitu count) {
DMA_CHANNEL * chan=&dma[0].chan[dmachan];
DmaChannel *chan=DmaChannels[dmachan];
if (chan->masked) return 0;
if (!count) return 0;
if (chan->addr_changed) ResetDMA8(chan);
if (chan->current_count>count) {
MEM_BlockWrite(chan->address,buffer,count);
chan->address+=count;
chan->current_address+=count;
chan->current_count-=count;
if (chan->currcnt>count) {
MEM_BlockWrite(chan->curraddr,buffer,count);
chan->curraddr+=count;
chan->currcnt-=count;
return count;
} else {
/* Copy remaining piece of first buffer */
MEM_BlockWrite(chan->address,buffer,chan->current_count);
if (!chan->mode.autoinit_enable) {
/* Set the end of counter bit */
dma[0].status_reg|=(1 << dmachan);
count=chan->current_count;
chan->current_address+=count;;
chan->current_count=0;
chan->enabled=false;
// Copy remaining piece of first buffer
MEM_BlockWrite(chan->curraddr,buffer,chan->currcnt);
if (!chan->autoinit) {
// Set the end of counter bit
//dma[0].status_reg|=(1 << dmachan);
count=chan->currcnt;
chan->curraddr+=count;;
chan->currcnt=0;
return count;
} else {
buffer+=chan->current_count;
Bitu left=count-(Bit16u)chan->current_count;
/* Autoinit reset the dma channel */
ResetDMA8(chan);
/* Copy the rest of the buffer */
MEM_BlockWrite(chan->address,buffer,left);
chan->address+=left;
chan->current_address+=left;
chan->current_count-=left;
buffer+=chan->currcnt;
Bitu left=count-(Bit16u)chan->currcnt;
// Autoinit reset the dma channel
chan->reset();
// Copy the rest of the buffer
MEM_BlockWrite(chan->curraddr,buffer,left);
chan->curraddr+=left;
chan->currcnt-=left;
return count;
}
}
@ -302,18 +231,21 @@ Bitu DMA_16_Write(Bitu dmachan,Bit8u * buffer,Bitu count) {
return 0;
}
void DMA_SetEnabled(DMA_CHANNEL * chan,bool enabled) {
void DMA_SetEnabled(DmaChannel * chan,bool enabled) {
if (chan->enabled == enabled) return;
chan->enabled=enabled;
if (chan->enable_callback) (*chan->enable_callback)(enabled);
}
void DMA_CheckEnabled(DMA_CHANNEL * chan) {
void DMA_CheckEnabled(void * usechan) {
DmaChannel * chan;
chan = (DmaChannel *)usechan;
bool enabled;
if (chan->masked) enabled=false;
else {
if (chan->mode.autoinit_enable) enabled=true;
else if (chan->current_count || chan->addr_changed) enabled=true;
if (chan->autoinit) enabled=true;
else if (chan->currcnt) enabled=true;
else enabled=false;
}
DMA_SetEnabled(chan,enabled);
@ -321,31 +253,28 @@ void DMA_CheckEnabled(DMA_CHANNEL * chan) {
void DMA_SetEnableCallBack(Bitu channel,DMA_EnableCallBack callback) {
DMA_CHANNEL * chan;
if (channel<4) {
chan=&dma[0].chan[channel];
} else if (channel<8) {
chan=&dma[1].chan[channel-4];
} else return;
DmaChannel * chan;
chan = DmaChannels[channel];
chan->enabled=false;
chan->enable_callback=callback;
DMA_CheckEnabled(chan);
}
void DMA_Init(Section* sec) {
Bitu i;
for (i=0;i<0x10;i++) {
IO_RegisterWriteHandler(i,write_dma,"DMA1");
IO_RegisterReadHandler(i,read_dma,"DMA1");
}
IO_RegisterWriteHandler(0x81,write_dma_page,"DMA Pages");
IO_RegisterWriteHandler(0x82,write_dma_page,"DMA Pages");
IO_RegisterWriteHandler(0x83,write_dma_page,"DMA Pages");
IO_RegisterWriteHandler(0x87,write_dma_page,"DMA Pages");
IO_RegisterReadHandler(0x81,read_dma_page,"DMA Pages");
IO_RegisterReadHandler(0x82,read_dma_page,"DMA Pages");
IO_RegisterReadHandler(0x83,read_dma_page,"DMA Pages");
IO_RegisterReadHandler(0x87,read_dma_page,"DMA Pages");
void DMA_Init(Section* sec) {
Bitu i;
DmaControllers[0] = new DmaController(0);
DmaControllers[1] = new DmaController(1);
for(i=0;i<4;i++) {
DmaChannels[i] = new DmaChannel(i,DmaControllers[0],false);
}
for(i=4;i<8;i++) {
DmaChannels[i] = new DmaChannel(i,DmaControllers[1],true);
}
}