uint32_t swaddr_read(swaddr_t addr, size_t len, uint8_t sreg) {
#ifdef DEBUG
assert(len == 1 || len == 2 || len == 4);
#endif
#ifdef SEGMENTATION
if (cpu.cr0.protect_enable)
addr = seg_translate(addr, sreg);
#endif
return lnaddr_read(addr, len);
}
void load_sreg(uint32_t sreg) {
uint8_t tmp[8];
int i;
for(i = 0; i < 8; ++ i)
tmp[i] = lnaddr_read(cpu.GDTR.base + cpu.sr[sreg].index * 8 + i, 1);
SegDesc *segdesc = (SegDesc*)tmp;
Assert(segdesc->present == 1, "Segdesc is not valid! 0x%x", cpu.GDTR.base + cpu.sr[sreg].index * 8);
Assert(cpu.sr[sreg].index * 8 < (segdesc->limit_19_16 << 16) + segdesc->limit_15_0, "Segment overflow!");
cpu.sr[sreg].invi = *segdesc;
}
lnaddr_t seg_translate(swaddr_t swaddr, uint8_t sreg) {
// Log("swaddr = 0x%x", swaddr);
Assert(cpu.cr0.protect_enable, "CR0 protect enable bit is not set!");
// Log("segment");
uint32_t segdesc_addr = cpu.gdtr.base + SREG(sreg).index;
// Log("addr = 0x%x", segdesc_addr);
SegDesc *segdesc = (SegDesc *)malloc(sizeof(SegDesc));
segdesc->val[0] = lnaddr_read(segdesc_addr, 4);
segdesc->val[1] = lnaddr_read(segdesc_addr + 4, 4);
// int i;
// for(i = 0; i < 2; ++i)
// Log("segdesc: 0x%08x", segdesc->val[i]);
uint32_t lnaddr = swaddr + (segdesc->base_31_24 << 24) +
(segdesc->base_23_16 << 16) + segdesc->base_15_0;
// Log("lnaddr = 0x%x", lnaddr);
// Assert(swaddr == lnaddr, "swaddr == lnaddr");
return lnaddr;
}
void raise_intr(uint8_t NO) {
/* TODO: Trigger an interrupt/exception with ``NO''.
* That is, use ``NO'' to index the IDT.
*/
push(cpu.EFLAGS.eflags);
push(cpu.CS.Selector.val);
push(cpu.eip);
GateDesc gd;
int i;
for (i = 0; i < sizeof(GateDesc); i++){
*((uint8_t*)(&gd)+i) = lnaddr_read(cpu.idtr.base+NO*sizeof(GateDesc)+i, 1);
}
cpu.CS.Selector.val = gd.segment;
cpu.CS.valid = false;
swaddr_t addr = (gd.offset_31_16<<16) | gd.offset_15_0;
cpu.eip = addr;
/* Jump back to cpu_exec() */
longjmp(jbuf, 1);
}
