diff options
| -rw-r--r-- | kernel/gdt.c | 10 | ||||
| -rw-r--r-- | kernel/gdt.h | 49 |
2 files changed, 58 insertions, 1 deletions
diff --git a/kernel/gdt.c b/kernel/gdt.c index 7d23289..92d3d4c 100644 --- a/kernel/gdt.c +++ b/kernel/gdt.c @@ -1,11 +1,14 @@ #include "gdt.h" +tss_entry tss = tss_entry_init(0xfffff800, 0x10, 0x0b, 0x13); + gdt_entry gdt[] = { gdt_entry_init(0, 0, 0), gdt_entry_init(0, 0xfffff, 0xc09a), // Code segment. gdt_entry_init(0, 0xfffff, 0xc092), // Data segment. gdt_entry_init(0, 0xfffff, 0xc0fa), // User mode code segment. gdt_entry_init(0, 0xfffff, 0xc0f2), // User mode data segment. + gdt_entry_init(0, sizeof(tss_entry), 0x00e9), // TSS. }; gdt_ptr gdtr = { @@ -14,6 +17,10 @@ gdt_ptr gdtr = { }; void gdt_init() { + gdt[5].base_low = (uint32_t)&tss & 0xffff; + gdt[5].base_mid = (uint32_t)&tss >> 16 & 0xff; + gdt[5].base_high = (uint32_t)&tss >> 24 & 0xff; + asm volatile( "lgdt (%0)\n" "mov %w1, %%ds\n" @@ -23,6 +30,7 @@ void gdt_init() { "mov %w1, %%ss\n" "ljmp $0x08, $.flush\n" ".flush:\n" - : : "r" (&gdtr), "r" (0x10) + "ltr %w2\n" + : : "r" (&gdtr), "r" (0x10), "r" (0x28) ); } diff --git a/kernel/gdt.h b/kernel/gdt.h index e2c5b46..36c37dd 100644 --- a/kernel/gdt.h +++ b/kernel/gdt.h @@ -4,6 +4,45 @@ #include "types.h" typedef struct { + uint32_t link; + + uint32_t esp0; + uint32_t ss0; + + uint32_t esp1; + uint32_t ss1; + + uint32_t esp2; + uint32_t ss2; + + uint32_t cr3; + + uint32_t eip; + uint32_t eflags; + + uint32_t eax; + uint32_t ecx; + uint32_t edx; + uint32_t ebx; + uint32_t esp; + uint32_t ebp; + uint32_t esi; + uint32_t edi; + + uint32_t es; + uint32_t cs; + uint32_t ss; + uint32_t ds; + uint32_t fs; + uint32_t gs; + + uint32_t ldt; + + uint16_t trap; + uint16_t iomap; +} __attribute__((packed)) tss_entry; + +typedef struct { uint16_t limit_low; uint16_t base_low; uint8_t base_mid; @@ -23,6 +62,16 @@ typedef struct { .limit_low = (l & 0xffff), \ .flags = (f | (l >> 8 & 0x0f00))} +#define tss_entry_init(e, s, c, d) { \ + .esp0 = e, \ + .ss0 = s, \ + .cs = c, \ + .ss = d, \ + .ds = d, \ + .es = d, \ + .fs = d, \ + .gs = d} + void gdt_init(); #endif |