/**********************************************************************
* DOSVM_Int25Handler
*
* Handler for int 25h (absolute disk read).
*/
void WINAPI DOSVM_Int25Handler( CONTEXT *context )
{
WCHAR drivespec[] = {'A', ':', '\\', 0};
BYTE *dataptr = CTX_SEG_OFF_TO_LIN( context, context->SegDs, context->Ebx );
DWORD begin;
DWORD length;
//!!
WORD *stack = CTX_SEG_OFF_TO_LIN(context, context->SegSs, context->Esp);
WORD eip = *stack;
WORD cs = *++stack;
context->Esp += 4;
PUSH_WORD16(context, (WORD)context->EFlags);
PUSH_WORD16(context, cs);
PUSH_WORD16(context, eip);
drivespec[0] += AL_reg( context );
if (GetDriveTypeW( drivespec ) == DRIVE_NO_ROOT_DIR ||
GetDriveTypeW( drivespec ) == DRIVE_UNKNOWN)
{
SET_CFLAG( context );
SET_AX( context, 0x0201 ); /* unknown unit */
return;
}
if (CX_reg( context ) == 0xffff)
{
begin = *(DWORD *)dataptr;
length = *(WORD *)(dataptr + 4);
dataptr = (BYTE *)CTX_SEG_OFF_TO_LIN( context,
*(WORD *)(dataptr + 8),
*(DWORD *)(dataptr + 6) );
}
else
{
begin = DX_reg( context );
length = CX_reg( context );
}
DOSVM_RawRead( AL_reg( context ), begin, length, dataptr, TRUE );
RESET_CFLAG( context );
}
/**********************************************************************
* DOSVM_HardwareInterruptRM
*
* Emulate call to interrupt handler in real mode.
*
* Either calls directly builtin handler or pushes interrupt frame to
* stack and changes instruction pointer to interrupt handler.
*/
void DOSVM_HardwareInterruptRM( CONTEXT86 *context, BYTE intnum )
{
FARPROC16 handler = DOSVM_GetRMHandler( intnum );
/* check if the call goes to an unhooked interrupt */
if (SELECTOROF(handler) == 0xf000)
{
/* if so, call it directly */
TRACE( "builtin interrupt %02x has been invoked "
"(through vector %02x)\n",
OFFSETOF(handler)/DOSVM_STUB_RM, intnum );
DOSVM_CallBuiltinHandler( context, OFFSETOF(handler)/DOSVM_STUB_RM );
}
else
{
/* the interrupt is hooked, simulate interrupt in DOS space */
WORD flag = LOWORD( context->EFlags );
TRACE( "invoking hooked interrupt %02x at %04x:%04x\n",
intnum, SELECTOROF(handler), OFFSETOF(handler) );
/* Copy virtual interrupt flag to pushed interrupt flag. */
if (context->EFlags & VIF_MASK)
flag |= IF_MASK;
else
flag &= ~IF_MASK;
PUSH_WORD16( context, flag );
PUSH_WORD16( context, context->SegCs );
PUSH_WORD16( context, LOWORD( context->Eip ));
context->SegCs = SELECTOROF( handler );
context->Eip = OFFSETOF( handler );
/* Clear virtual interrupt flag and trap flag. */
context->EFlags &= ~(VIF_MASK | TF_MASK);
}
}
/**********************************************************************
* DOSVM_HardwareInterruptPM
*
* Emulate call to interrupt handler in 16-bit or 32-bit protected mode.
*
* Pushes interrupt frame to stack and changes instruction
* pointer to interrupt handler.
*/
void DOSVM_HardwareInterruptPM( CONTEXT86 *context, BYTE intnum )
{
if(DOSVM_IsDos32())
{
FARPROC48 addr = DOSVM_GetPMHandler48( intnum );
if (addr.selector == DOSVM_dpmi_segments->int48_sel)
{
TRACE( "builtin interrupt %02lx has been invoked "
"(through vector %02x)\n",
addr.offset / DOSVM_STUB_PM48, intnum );
if (intnum == 0x25 || intnum == 0x26)
DOSVM_PushFlags( context, TRUE, FALSE );
else if (DOSVM_IsIRQ(intnum))
DOSVM_PrepareIRQ( context, TRUE );
DOSVM_BuildCallFrame( context,
DOSVM_IntProcRelay,
DOSVM_GetBuiltinHandler(
addr.offset/DOSVM_STUB_PM48 ) );
}
else
{
DWORD *stack;
TRACE( "invoking hooked interrupt %02x at %04x:%08lx\n",
intnum, addr.selector, addr.offset );
if (DOSVM_IsIRQ(intnum))
DOSVM_PrepareIRQ( context, FALSE );
/* Push the flags and return address on the stack */
stack = CTX_SEG_OFF_TO_LIN(context, context->SegSs, context->Esp);
*(--stack) = context->EFlags;
*(--stack) = context->SegCs;
*(--stack) = context->Eip;
context->Esp += -12;
/* Jump to the interrupt handler */
context->SegCs = addr.selector;
context->Eip = addr.offset;
}
}
else
{
FARPROC16 addr = DOSVM_GetPMHandler16( intnum );
if (SELECTOROF(addr) == DOSVM_dpmi_segments->int16_sel)
{
TRACE( "builtin interrupt %02x has been invoked "
"(through vector %02x)\n",
OFFSETOF(addr)/DOSVM_STUB_PM16, intnum );
if (intnum == 0x25 || intnum == 0x26)
DOSVM_PushFlags( context, FALSE, FALSE );
else if (DOSVM_IsIRQ(intnum))
DOSVM_PrepareIRQ( context, TRUE );
DOSVM_BuildCallFrame( context,
DOSVM_IntProcRelay,
DOSVM_GetBuiltinHandler(
OFFSETOF(addr)/DOSVM_STUB_PM16 ) );
}
else
{
TRACE( "invoking hooked interrupt %02x at %04x:%04x\n",
intnum, SELECTOROF(addr), OFFSETOF(addr) );
if (DOSVM_IsIRQ(intnum))
DOSVM_PrepareIRQ( context, FALSE );
/* Push the flags and return address on the stack */
PUSH_WORD16( context, LOWORD(context->EFlags) );
PUSH_WORD16( context, context->SegCs );
PUSH_WORD16( context, LOWORD(context->Eip) );
/* Jump to the interrupt handler */
context->SegCs = HIWORD(addr);
context->Eip = LOWORD(addr);
}
}
}
