41 lines
1022 B
C
41 lines
1022 B
C
#include <kernel/x86/gdt.h>
|
|
|
|
#ifdef __TESTING__
|
|
#include <kernel/_kernel.h>
|
|
#endif
|
|
|
|
uint64_t create_descriptor(uint32_t base, uint32_t limit, uint16_t flag)
|
|
{
|
|
uint64_t descriptor;
|
|
|
|
descriptor = limit & 0x000F0000;
|
|
descriptor |= (flag << 8) & 0x00F0FF00;
|
|
descriptor |= (base >> 16) & 0x000000FF;
|
|
descriptor |= base & 0xFF000000;
|
|
|
|
descriptor <<= 32;
|
|
|
|
descriptor |= base << 16;
|
|
descriptor |= limit & 0x0000FFFF;
|
|
|
|
return descriptor;
|
|
}
|
|
|
|
void gdt_init(uint64_t* gdt)
|
|
{
|
|
#ifdef __TESTING__
|
|
kinfo("Initializing the GDT");
|
|
#endif
|
|
gdt[0] = create_descriptor(0, 0, 0); // null
|
|
gdt[1] = create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL0)); // kernel code
|
|
gdt[2] = create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL0)); // kernel data
|
|
gdt[3] = create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL3)); // user code
|
|
gdt[4] = create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL3)); // user data
|
|
|
|
setGdt((sizeof(uint64_t) * GDT_SIZE) - 1, &(gdt[0])); // limit, base
|
|
reloadSegments();
|
|
#ifdef __TESTING__
|
|
kinfo("Initialized the GDT");
|
|
#endif
|
|
}
|