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BIOS serial port interface: Do not misinterpret DCD as timeout.

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@3636
This commit is contained in:
Ralf Grillenberger 2010-08-12 14:58:17 +00:00
parent b234560075
commit da00ef32bb
1 changed files with 19 additions and 21 deletions
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40
src/ints/bios.cpp
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@ -434,18 +434,16 @@ static Bitu INT17_Handler(void) {
return CBRET_NONE;
}
static Bit8u INT14_Wait(Bit16u port, Bit8u mask, Bit8u timeout) {
static bool INT14_Wait(Bit16u port, Bit8u mask, Bit8u timeout, Bit8u* retval) {
double starttime = PIC_FullIndex();
double timeout_f = timeout * 1000.0;
Bit8u retval;
while (((retval = IO_ReadB(port)) & mask) != mask) {
while (((*retval = IO_ReadB(port)) & mask) != mask) {
if (starttime < (PIC_FullIndex() - timeout_f)) {
retval |= 0x80;
break;
return false;
}
CALLBACK_Idle();
}
return retval;
return true;
}
static Bitu INT14_Handler(void) {
@ -500,7 +498,7 @@ static Bitu INT14_Handler(void) {
CALLBACK_SCF(false);
break;
}
case 0x01: { // Transmit character
case 0x01: // Transmit character
// Parameters: Return:
// AL: character AL: unchanged
// AH: 0x01 AH: line status from just before the char was sent
@ -510,20 +508,19 @@ static Bitu INT14_Handler(void) {
// set DTR & RTS on
IO_WriteB(port+4,0x3);
// wait for DSR & CTS
reg_ah = INT14_Wait(port+6, 0x30, timeout);
if (!(reg_ah & 0x80)) {
if (INT14_Wait(port+6, 0x30, timeout, &reg_ah)) {
// wait for TX buffer empty
reg_ah = INT14_Wait(port+5, 0x20, timeout);
if (!(reg_ah & 0x80)) {
if (INT14_Wait(port+5, 0x20, timeout, &reg_ah)) {
// fianlly send the character
IO_WriteB(port,reg_al);
}
} // else timed out
} else
reg_ah |= 0x80;
} else // timed out
reg_ah |= 0x80;
CALLBACK_SCF(false);
break;
}
case 0x02: // Read character
// Parameters: Return:
// AH: 0x02 AL: received character
@ -537,15 +534,16 @@ static Bitu INT14_Handler(void) {
IO_WriteB(port+4,0x1);
// wait for DSR
reg_ah = INT14_Wait(port+6, 0x20, timeout);
if (!(reg_ah & 0x80)) {
if (INT14_Wait(port+6, 0x20, timeout, &reg_ah)) {
// wait for character to arrive
reg_ah = INT14_Wait(port+5, 0x01, timeout);
if (!(reg_ah & 0x80)) {
if (INT14_Wait(port+5, 0x01, timeout, &reg_ah)) {
reg_ah &= 0x1E;
reg_al = IO_ReadB(port);
}
}
} else
reg_ah |= 0x80;
} else
reg_ah |= 0x80;
CALLBACK_SCF(false);
break;
case 0x03: // get status