/**
* IDT flag overview
*
* flags = x xx 0x11x 000 ?????
* | | | \ SS = Storage Segment (0 for interrupts)
* | | \ D = Size of gate: 1 = 32 bits; 0 = 16 bits
* | \ DPL = Num. higher PL from which it is accessible
* \ P = Segment Present bit
*/
void setInterruptHandler(int vector, void (*handler)(), int maxAccessibleFromPL)
{
Word flags = (Word)(maxAccessibleFromPL << 13);
flags |= 0x8E00; // P = 1, D = 1, Type = 1110 (Interrupt Gate)
idt[vector].lowOffset = lowWord((DWord)handler);
idt[vector].segmentSelector = __KERNEL_CS;
idt[vector].flags = flags;
idt[vector].highOffset = highWord((DWord)handler);
}
void setTrapHandler(int vector, void (*handler)(), int maxAccessibleFromPL)
{
Word flags = (Word)(maxAccessibleFromPL << 13);
// Changed to 0x8e00 to convert it to an 'interrupt gate' and so the system calls will be thread-safe.
flags |= 0x8e00; // P = 1, D = 1, Type = 1110 (Interrupt Gate)
//flags |= 0x8F00; // P = 1, D = 1, Type = 1111 (Trap Gate)
idt[vector].lowOffset = lowWord((DWord)handler);
idt[vector].segmentSelector = __KERNEL_CS;
idt[vector].flags = flags;
idt[vector].highOffset = highWord((DWord)handler);
}
void setInterruptHandler(int vector, void (*handler)(), int maxAccessibleFromPL)
{
/***********************************************************************/
/* THE INTERRUPTION GATE FLAGS: R1: pg. 5-11 */
/* *************************** */
/* flags = x xx 0x110 000 ????? */
/* | | | */
/* | | \ D = Size of gate: 1 = 32 bits; 0 = 16 bits */
/* | \ DPL = Num. higher PL from which it is accessible */
/* \ P = Segment Present bit */
/***********************************************************************/
Word flags = (Word)(maxAccessibleFromPL << 13);
flags |= 0x8E00; /* P = 1, D = 1, Type = 1110 (Interrupt Gate) */
idt[vector].lowOffset = lowWord((DWord)handler);
idt[vector].segmentSelector = __KERNEL_CS;
idt[vector].flags = flags;
idt[vector].highOffset = highWord((DWord)handler);
}
void setTrapHandler(int vector, void (*handler)(), int maxAccessibleFromPL)
{
/***********************************************************************/
/* THE TRAP GATE FLAGS: R1: pg. 5-11 */
/* ******************** */
/* flags = x xx 0x111 000 ????? */
/* | | | */
/* | | \ D = Size of gate: 1 = 32 bits; 0 = 16 bits */
/* | \ DPL = Num. higher PL from which it is accessible */
/* \ P = Segment Present bit */
/***********************************************************************/
Word flags = (Word)(maxAccessibleFromPL << 13);
//flags |= 0x8F00; /* P = 1, D = 1, Type = 1111 (Trap Gate) */
/* Changed to 0x8e00 to convert it to an 'interrupt gate' and so
the system calls will be thread-safe. */
flags |= 0x8E00; /* P = 1, D = 1, Type = 1110 (Interrupt Gate) */
idt[vector].lowOffset = lowWord((DWord)handler);
idt[vector].segmentSelector = __KERNEL_CS;
idt[vector].flags = flags;
idt[vector].highOffset = highWord((DWord)handler);
}
DSCREC * PASCAL CODESIZE
regcheck (
DSCREC *arg,
UCHAR minus,
register struct exprec *ptr
){
struct psop *pso; /* parse stack operand structure */
register struct ar *pAR;
USHORT reg;
pso = &(arg->dsckind.opnd);
pAR = ptr->p->p;
if (M_REGRESULT & pso->dtype) {
/* Is some register */
if (ptr->p->parenflag || pAR->bracklevel) {
/* Have index reg in []s */
/* Lose size based on register */
pso->dsize = 0;
reg = pso->dsegment->offset;
/* Must be index or ptr reg */
switch(pso->dsegment->symu.regsym.regtype)
{
default:
errorc (E_IBR);
break;
case INDREG:
if (reg <= 5)
/* Have base reg BX | BP */
if (pAR->base)
errorc (E_DBR);
else
pAR->base = reg;
else /* Have index reg DI | SI */
if (pAR->index)
errorc (E_DIR);
else
pAR->index = reg;
break;
#ifdef V386
case DWRDREG:
/* Have 386 reg in []s */
if (minus == 2)
{
if (pAR->index & 0xf)
errorc(E_DIR);
pAR->index |= 8 | reg;
}
else if (pAR->base)
{
if (pAR->index)
errorc(E_DIR);
if (reg == 4) {
/* swap base with index
* to allow [index][eSp] */
pAR->index = pAR->base;
pAR->base = 4|8;
}
else
pAR->index = reg|8;
}
else
pAR->base = reg|8;
break;
#endif /* V386 */
}
if (minus == TRUE && (ptr->valright == arg))
errorc (E_IUR);
oblititem (arg);
return (defaultdsc ());
}
else {
errorc(E_IUR);
return (arg);
}
}
#ifdef V386 /* scaled indexing modes */
else if (minus == 2 && (M_RCONST & pso->dtype))
{
if (pAR->index&0x70)
errorc(E_MBR);
if (highWord(arg->dsckind.opnd.doffset))
goto scaleErr;
switch((SHORT) arg->dsckind.opnd.doffset) {
case 1:
pAR->index |= 0x10;
break;
case 2:
pAR->index |= 0x20;
break;
case 4:
pAR->index |= 0x30;
break;
case 8:
pAR->index |= 0x40;
break;
scaleErr:
default:
error(E_EXP, "scale value of 1,2,4 or 8");
}
oblititem (arg);
return (defaultdsc ());
}
#endif /* V386 */
else return (arg);
}