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IDT

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Ben
2019-05-02 17:29:24 +01:00
parent 390fc87c20
commit 44330e8427
14 changed files with 576 additions and 18 deletions
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15
kernel/gdt.cpp
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@@ -25,23 +25,22 @@ void lgdt(GDT_t GDT) {
asm ("lgdt %0" : : "m"(GDT));
}
int InitGDT() {
void GDT_Init() {
_GDTptr.limit = (sizeof(SegmentDescriptor_t) * 5) - 1;
_GDTptr.base = (uint32_t)&_GDT;
// Null segment
SetGDTGate(0, 0, 0, 0, 0);
// Code Base 0 limit 32 Access EXEC + RW
SetGDTGate(1, 0x00000000, 0xFFFFFFFF, GDT_ACCESS_PRESENT | GDT_ACCESS_EXEC | GDT_ACCESS_RW, GDT_FLAG_GR_PAGE | GDT_FLAG_SZ_32B);
// Data Base 0 Limit 32 Access RW
SetGDTGate(2, 0x00000000, 0xFFFFFFFF, GDT_ACCESS_PRESENT | GDT_ACCESS_RW, GDT_FLAG_GR_PAGE | GDT_FLAG_SZ_32B);
GDT_Set_Gate(0, 0, 0, 0, 0);
// Code Base 0 limit 32 Access EXEC + RW
GDT_Set_Gate(1, 0x00000000, 0xFFFFFFFF, GDT_ACCESS_PRESENT | GDT_ACCESS_EXEC | GDT_ACCESS_RW, GDT_FLAG_GR_PAGE | GDT_FLAG_SZ_32B);
// Data Base 0 Limit 32 Access RW
GDT_Set_Gate(2, 0x00000000, 0xFFFFFFFF, GDT_ACCESS_PRESENT | GDT_ACCESS_RW, GDT_FLAG_GR_PAGE | GDT_FLAG_SZ_32B);
lgdt(_GDTptr);
SEGMENTS_RELOAD();
return 1;
}
void SetGDTGate(uint32_t index, uint32_t baseAddr, uint32_t limitAddr, uint8_t accessLvl, uint8_t flags) {
void GDT_Set_Gate(uint32_t index, uint32_t baseAddr, uint32_t limitAddr, uint8_t accessLvl, uint8_t flags) {
if (index > 5) return;
_GDT[index].base_low = (baseAddr & 0xFFFF);
_GDT[index].base_middle = (baseAddr >> 16) & 0xFF;