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int 13h emulation: call IDE code where, if disk belongs to IDE

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controller, the registers are hacked as if the BIOS had carried out IDE
commands.
IDE emulation: moved C/H/S counting up, so it only occurs if another
sector is beginning to read. added code to hack IDE registers as if BIOS
IDE read. To my amazement, IDE emulation now passes all tests given by
Windows 3.11 Windows for Workgroup 32-bit disk driver WDCTRL, and
Windows 3.11 is observed issuing IDE read/write commands on startup!
Yay! Now if I could figure out what Windows 95 expects it would make my
day... and I could remove my bitter sarcastic remarks from the source
code.
This commit is contained in:
Jonathan Campbell 2013-10-22 23:21:09 -07:00
parent edbaa463af
commit b76782b0f6
2 changed files with 70 additions and 16 deletions
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81
src/hardware/ide.cpp
View File

@ -528,6 +528,19 @@ void IDEATADevice::io_completion() {
/* depending on the command, either continue it or finish up */
switch (command) {
case 0x20:/* READ SECTOR */
/* OK, decrement count, increment address */
/* NTS: Remember that count == 0 means the host wanted to transfer 256 sectors */
if ((count&0xFF) == 0) count = 255;
else if ((count&0xFF) == 1) {
/* end of the transfer */
count = 0;
status = IDE_STATUS_DRIVE_READY|IDE_STATUS_DRIVE_SEEK_COMPLETE;
state = IDE_DEV_READY;
allow_writing = true;
return;
}
else count--;
/* having read the sector, increment the disk address. we do it in a way
the host will read back the "current" position.
@ -571,19 +584,6 @@ void IDEATADevice::io_completion() {
}
}
/* OK, decrement count, increment address */
/* NTS: Remember that count == 0 means the host wanted to transfer 256 sectors */
if ((count&0xFF) == 0) count = 255;
else if ((count&0xFF) == 1) {
/* end of the transfer */
count = 0;
status = IDE_STATUS_DRIVE_READY|IDE_STATUS_DRIVE_SEEK_COMPLETE;
state = IDE_DEV_READY;
allow_writing = true;
return;
}
else count--;
/* cause another delay, another sector read */
state = IDE_DEV_BUSY;
status = IDE_STATUS_BUSY;
@ -1146,6 +1146,55 @@ static IDEDevice* GetIDESelectedDevice(IDEController *ide) {
static void ide_baseio_w(Bitu port,Bitu val,Bitu iolen);
/* this is called after INT 13h AH=0x02 READ DISK to change IDE state to simulate the BIOS in action.
* this is needed for old "32-bit disk drivers" like WDCTRL in Windows 3.11 Windows for Workgroups,
* which issues INT 13h to read-test and then reads IDE registers to see if they match expectations */
void IDE_EmuINT13DiskReadByBIOS(unsigned char disk,unsigned int cyl,unsigned int head,unsigned sect) {
IDEController *ide;
IDEDevice *dev;
Bitu idx,ms;
if (disk < 0x80) return;
for (idx=0;idx < MAX_IDE_CONTROLLERS;idx++) {
ide = GetIDEController(idx);
if (ide == NULL) continue;
/* TODO: Print a warning message if the IDE controller is busy (debug/warning message) */
/* for master/slave device... */
for (ms=0;ms < 2;ms++) {
dev = ide->device[ms];
if (dev == NULL) continue;
/* TODO: Print a warning message if the IDE device is busy or in the middle of a command */
/* TODO: Forcibly device-reset the IDE device */
ide_baseio_w(ide->base_io+6,0x00+(ms<<4),1); /* re-use our I/O handler to select IDE device */
if (dev->type == IDE_TYPE_HDD) {
IDEATADevice *ata = (IDEATADevice*)dev;
if ((ata->bios_disk_index-2) == (disk-0x80)) {
/* hack IDE state as if a BIOS executing IDE disk routines.
* This is required if we want IDE emulation to work with Windows 3.11 Windows for Workgroups 32-bit disk access (WDCTRL),
* because the driver "tests" the controller by issuing INT 13h calls then reading back IDE registers to see if
* they match the C/H/S it requested */
dev->feature = 0x00; /* clear error (WDCTRL test phase 5/C/13) */
dev->count = 0x00; /* clear sector count (WDCTRL test phase 6/D/14) */
dev->lba[0] = sect; /* leave sector number the same (WDCTRL test phase 7/E/15) */
dev->lba[1] = cyl; /* leave cylinder the same (WDCTRL test phase 8/F/16) */
dev->lba[2] = cyl >> 8; /* ...ditto */
ide->drivehead = dev->drivehead = 0xA0 | (ms<<4) | head; /* drive head and master/slave (WDCTRL test phase 9/10/17) */
dev->status = IDE_STATUS_DRIVE_READY|IDE_STATUS_DRIVE_SEEK_COMPLETE; /* status (WDCTRL test phase A/11/18) */
dev->allow_writing = true;
}
}
}
}
}
/* this is called by src/ints/bios_disk.cpp whenever INT 13h AH=0x00 is called on a hard disk.
* this gives us a chance to update IDE state as if the BIOS had gone through with a full disk reset as requested. */
void IDE_ResetDiskByBIOS(unsigned char disk) {
@ -1525,8 +1574,8 @@ void IDEATADevice::writecommand(uint8_t cmd) {
return;
}
fprintf(stderr,"IDE ATA command %02x dh=0x%02x count=0x%02x lba/chs=%02x/%02x%02x\n",cmd,
drivehead,count,lba[0],lba[1],lba[2]);
fprintf(stderr,"IDE ATA command %02x dh=0x%02x count=0x%02x chs=%02x/%02x/%02x\n",cmd,
drivehead,count,lba[2],lba[1],lba[0]);
LOG(LOG_SB,LOG_NORMAL)("IDE ATA command %02x",cmd);
/* if the drive is asleep, then writing a command wakes it up */
@ -1735,7 +1784,7 @@ static Bitu _ide_baseio_r(Bitu port,Bitu iolen) {
static Bitu ide_baseio_r(Bitu port,Bitu iolen) {
Bitu r = _ide_baseio_r(port,iolen);
// fprintf(stderr," > %02X\n",r);
// fprintf(stderr,"IDE base[0x%03x] > %02X\n",port,r);
return r;
}

5
src/ints/bios_disk.cpp
View File

@ -350,6 +350,7 @@ static void readDAP(Bit16u seg, Bit16u off) {
}
void IDE_ResetDiskByBIOS(unsigned char disk);
void IDE_EmuINT13DiskReadByBIOS(unsigned char disk,unsigned int cyl,unsigned int head,unsigned sect);
static Bitu INT13_DiskHandler(void) {
Bit16u segat, bufptr;
@ -427,6 +428,10 @@ static Bitu INT13_DiskHandler(void) {
bufptr = reg_bx;
for(i=0;i<reg_al;i++) {
last_status = imageDiskList[drivenum]->Read_Sector((Bit32u)reg_dh, (Bit32u)(reg_ch | ((reg_cl & 0xc0)<< 2)), (Bit32u)((reg_cl & 63)+i), sectbuf);
/* IDE emulation: simulate change of IDE state that would occur on a real machine after INT 13h */
IDE_EmuINT13DiskReadByBIOS(reg_dl, (Bit32u)(reg_ch | ((reg_cl & 0xc0)<< 2)), (Bit32u)reg_dh, (Bit32u)((reg_cl & 63)+i));
if((last_status != 0x00) || (killRead)) {
LOG_MSG("Error in disk read");
killRead = false;