diff options
Diffstat (limited to 'src/c/gdt.c')
| -rw-r--r-- | src/c/gdt.c | 35 |
1 files changed, 10 insertions, 25 deletions
diff --git a/src/c/gdt.c b/src/c/gdt.c index e3d2b4c..8791cbe 100644 --- a/src/c/gdt.c +++ b/src/c/gdt.c @@ -1,46 +1,31 @@ +#include<source/gdt.h> #include<types.h> -struct gdt_entry -{ - uint16_t limit; - uint16_t base1; - uint8_t base2; - uint8_t access; - uint8_t limit_flags; - uint8_t base3; -} __attribute__((packed)); - -struct gdt_pointer -{ - uint16_t size; - uint32_t offset; -} __attribute__((packed)); - extern void load_gdt(struct gdt_pointer *gdtp); struct gdt_entry gdt[5]; struct gdt_pointer gdtp; -void init_gdt_entry(size_t num, uint32_t limit, uint32_t base, uint8_t access, uint8_t limit_flags) +void init_gdt_entry(size_t num, uint16_t limit, uint32_t base, uint8_t access, uint8_t limit_flags) { gdt[num].limit=limit; gdt[num].base1=(base & 0xffff); - gdt[num].base2=(base & 0xff0000) >> 16; + gdt[num].base2=(uint8_t)((base & 0xff0000) >> 16); gdt[num].access=access; gdt[num].limit_flags=limit_flags; - gdt[num].base3=(base & 0xff000000) >> 24; + gdt[num].base3=(uint8_t)((base & 0xff000000) >> 24); } -void init_gdt_table() +void init_gdt_table(void) { gdtp.size=sizeof(gdt)-1; gdtp.offset=(uint32_t)&gdt; - init_gdt_entry(0,0,0,0,0); // null segment - init_gdt_entry(1,0xffffffff,0,0b10011010,0b11001111); // code segment - init_gdt_entry(2,0xffffffff,0,0b10010010,0b11001111); // data segment - init_gdt_entry(3,0xffffffff,0,0b11111010,0b11001111); // user mode code segment - init_gdt_entry(4,0xffffffff,0,0b11110010,0b11001111); // user mode data segment + init_gdt_entry(0,0,0,0,0); // null segment + init_gdt_entry(1,0xffff,0,0x9a,0xcf); // code segment + init_gdt_entry(2,0xffff,0,0x92,0xcf); // data segment + init_gdt_entry(3,0xffff,0,0xfa,0xcf); // user mode code segment + init_gdt_entry(4,0xffff,0,0xf2,0xcf); // user mode data segment load_gdt(&gdtp); } |