TSS GDT Gate
Posted: Fri Feb 24, 2006 7:37 pm
Is my code for my TSS GDT Gate good?
Code: Select all
struct KeGDTEntry gdte[6];
struct KeGDTPtr gdt;
void KeGDTSetGate(int num, unsigned long base, unsigned long limit, unsigned char access,unsigned char gran)
{
gdte[num].base_low = (base & 0xFFFF);
gdte[num].base_middle = (base >> 16) & 0xFF;
gdte[num].base_high = (base >> 24) & 0xFF;
gdte[num].limit_low = (limit & 0xFFFF);
gdte[num].granularity = ((limit >> 16) & 0x0F);
gdte[num].granularity |= (gran & 0xF0);
gdte[num].access = access;
}
void KeGDTSetTSS(int num)
{
gdte[num].base_low = 0;
gdte[num].base_middle=0;
gdte[num].base_high=0;
gdte[num].limit_low = 103;
gdte[num].access = 0x89;
gdte[num].granularity = 0;
}
void KeGDTInstall()
{
gdt.limit = (sizeof(struct KeGDTEntry)*6) - 1;
gdt.base = (unsigned int)&gdte;
/* [0x00] */ KeGDTSetGate(0,0,0,0,0);
/* [0x08] */ KeGDTSetGate(1,0,0xFFFFFFFF,0x9A,0xCF); // Ring0 CS
/* [0x10] */ KeGDTSetGate(2,0,0xFFFFFFFF,0x92,0xCF); // Ring0 DS
/* [0x18] */ KeGDTSetTSS(3);
/* [0x20] */ KeGDTSetGate(4,0,0xFFFFFFFF,0xFA,0xCF); // Ring3 CS
/* [0x28] */ KeGDTSetGate(5,0,0xFFFFFFFF,0xF2,0xCF); // Ring3 DS
KeSetGDT();
}