DWord TStringStack::popdw(){
DWord _RetDWord=0;
if (!String) return (DWord)0;
_RetDWord=(DWord)popw();
_RetDWord+=(DWord)popw()<<16;
return _RetDWord;
}
static void do_retf(struct RealModeCallStructure *rmreg, int rmask)
{
unsigned int ssp, sp;
ssp = SEGOFF2LINEAR(READ_RMREG(ss, rmask), 0);
sp = READ_RMREG(sp, rmask);
RMREG(ip) = popw(ssp, sp);
RMREG(cs) = popw(ssp, sp);
RMREG(sp) += 4;
}
void handle_v86_fault( Virtual86Regs_s * regs, uint32 nErrorCode )
{
unsigned char *csp, *ssp;
unsigned long ip, sp;
int nInst;
// if ( 0xffff == (regs->eip & 0xffff) && 0xffff == regs->cs ) {
// return_to_32bit( regs, 0 );
// return;
// }
csp = ( unsigned char * )( regs->cs << 4 );
ssp = ( unsigned char * )( regs->ss << 4 );
sp = regs->esp & 0xffff;
ip = regs->eip & 0xffff;
nInst = popb( csp, ip );
switch ( nInst )
{
/* Operand size override */
case 0x66:
printk( "WARNING : 32 bit code run in v86 mode! Flags are not handled properly!\n" );
nInst = popb( csp, ip );
switch ( nInst )
{
/* pushfd */
case 0x9c:
regs->esp = ( regs->esp - 4 ) & 0xffff;
regs->eip = ( regs->eip + 2 ) & 0xffff;
pushl( ssp, sp, regs->eflags );
return;
/* popfd */
case 0x9d:
regs->esp = ( regs->esp + 4 ) & 0xffff;
regs->eip = ( regs->eip + 2 ) & 0xffff;
regs->eflags = popl( ssp, sp );
return;
/* iretd */
case 0xcf:
regs->esp = ( regs->esp + 12 ) & 0xffff;
regs->eip = ( uint16 )( popl( ssp, sp ) & 0xffff );
regs->cs = ( uint16 )popl( ssp, sp );
return;
/* need this to avoid a fallthrough */
default:
printk( "ERROR : unknown v86 32 bit instruction %x\n", nInst );
return_to_32bit( regs, -EFAULT );
}
/* pushf */
case 0x9c:
regs->esp = ( regs->esp - 2 ) & 0xffff;
regs->eip = ( regs->eip + 1 ) & 0xffff;
pushw( ssp, sp, regs->eflags & 0xffff );
return;
/* popf */
case 0x9d:
regs->esp = ( regs->esp + 2 ) & 0xffff;
regs->eip = ( regs->eip + 1 ) & 0xffff;
regs->eflags = ( regs->eflags & 0xffff0000 ) | ( popw( ssp, sp ) & 0xffff );
return;
/* int xx */
case 0xcd:
{
int intno = popb( csp, ip );
regs->eip = ( regs->eip + 2 ) & 0xffff;
do_int( regs, intno, ssp, sp );
return;
}
/* iret */
case 0xcf:
regs->esp = ( regs->esp + 6 ) & 0xffff;
regs->eip = popw( ssp, sp ) & 0xffff;
regs->cs = popw( ssp, sp );
regs->eflags = ( regs->eflags & 0xffff0000 ) | ( popw( ssp, sp ) & 0xffff );
if ( 0xffff == ( regs->eip & 0xffff ) && 0xffff == regs->cs )
{
return_to_32bit( regs, 0 );
}
return;
/* cli */
case 0xfa:
regs->eip = ( regs->eip + 1 ) & 0xffff;
regs->eflags &= ~EFLG_IF;
return;
/* sti */
case 0xfb:
/* The interrupts should actually be restored after the NEXT instruction!
* Hope this works. As long as no DOS/BIOS code swaps the stack,
* nothing bad should happen.
*/
regs->eip = ( regs->eip + 1 ) & 0xffff;
regs->eflags |= EFLG_IF;
return;
default:
printk( "ERROR : unknown v86 16 bit instruction %x\n", nInst );
return_to_32bit( regs, -EFAULT );
}
}
