diff options
Diffstat (limited to 'src/kernel/gdt.c')
| -rw-r--r-- | src/kernel/gdt.c | 52 |
1 files changed, 0 insertions, 52 deletions
diff --git a/src/kernel/gdt.c b/src/kernel/gdt.c deleted file mode 100644 index 406b40c..0000000 --- a/src/kernel/gdt.c +++ /dev/null @@ -1,52 +0,0 @@ -#include "gdt.h" -#include <stdint.h> - -GDT_t table = 0x0; -extern GDTR_t gdtr; -void get_gdtr() { - uint32_t base = 0x0000; - - table[0] = make_descriptor(0, 0, 0); - table[1] = make_descriptor(base, 0x3FFFF, make_code(0, 0, 1)); - table[2] = make_descriptor(base, 0x3FFFF, make_data(0, 0, 1)); - - gdtr.size = sizeof(Segment_Descriptor_t) * 3 - 1; - gdtr.offset = base; -} - -uint16_t make_code(uint8_t priv, uint8_t dc, uint8_t rw) { - uint16_t access = 0; - access |= (1 << 7); - access |= (priv << 5); - access |= (0b11 << 3); - access |= (dc << 2); - access |= (rw << 1); // 10 - access <<= 8; - access |= FLAG; - return access; -} - -uint16_t make_data(uint8_t priv, uint8_t dc, uint8_t rw) { - uint16_t access = 0; - access |= (1 << 7); - access |= (priv << 5); - access |= (0b10 << 3); - access |= (dc << 2); - access |= (rw << 1); // 10 - access <<= 8; - access |= FLAG; - return access; -} - -Segment_Descriptor_t make_descriptor(uint32_t base, uint32_t limit, - uint16_t access_flag) { - uint16_t lim_low = limit; - uint16_t base_low = base; - uint8_t base_mid = (base >> 16); - uint8_t access_byte = access_flag >> 8; - uint8_t lim_flag = ((access_flag << 4) | (limit >> 16)); - uint8_t base_high = (base >> 24); - return (Segment_Descriptor_t){ - lim_low, base_low, base_mid, access_byte, lim_flag, base_high, - }; -} |
