diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cpu.c | 51 |
1 files changed, 40 insertions, 11 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index e0ed188..b541513 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -7,6 +7,7 @@ #define CODE_SEG_INDEX 1 #define DATA_SEG_INDEX 2 +#define TASK_SEG_INDEX 3 struct dtr64 { @@ -28,6 +29,7 @@ enum segment_descriptor_type { CODE64_SEG, DATA_SEG, + TASK64_SEG, }; struct gate_descriptor @@ -46,9 +48,22 @@ enum gate_descriptor_type TRAP64_GATE, }; +struct task64_segment +{ + uint32_t reserved0; + uint64_t rsp0; + uint64_t rsp1; + uint64_t rsp2; + uint64_t reserved1; + uint64_t ist[7]; + uint16_t reserved2; + uint16_t iomap_base; +}; + // TODO: is 16 enough? static struct segment_descriptor gdt[GDT_ENTRIES]; static struct gate_descriptor idt[IDT_ENTRIES]; +static struct task64_segment tss; static void set_gdt(int index, uint64_t base, @@ -71,26 +86,32 @@ static void set_gdt(int index, gdt[index].access = 0x92; gdt[index].flags_limit16 |= 0xc0; break; + case TASK64_SEG: + gdt[index].access = 0x89; + //TODO: make this cleaner i don't like it + gdt[index+1].limit0 = (base >> 32) & 0xffff; + gdt[index+1].base0 = (base >> 48) & 0xffff; + break; }; } -static void set_idt(int index, - uint16_t selector, - uint64_t offset, - enum gate_descriptor_type type) +static void set_idt(int vec, + uint16_t selector, + uint64_t offset, + enum gate_descriptor_type type) { - idt[index].offset0 = offset & 0xffff; - idt[index].selector = selector; - idt[index].offset16 = (offset >> 16) & 0xffff; - idt[index].offset32 = (offset >> 32) & 0xffffffff; + idt[vec].offset0 = offset & 0xffff; + idt[vec].selector = selector; + idt[vec].offset16 = (offset >> 16) & 0xffff; + idt[vec].offset32 = (offset >> 32) & 0xffffffff; switch (type) { case INT64_GATE: - idt[index].access = 0x8e; + idt[vec].access = 0x8e; break; case TRAP64_GATE: - idt[index].access = 0x8f; + idt[vec].access = 0x8f; break; } } @@ -99,6 +120,7 @@ static void gdt_init(void) { set_gdt(CODE_SEG_INDEX, 0, (uint64_t)-1, CODE64_SEG); set_gdt(DATA_SEG_INDEX, 0, (uint64_t)-1, DATA_SEG); + set_gdt(TASK_SEG_INDEX, (uint64_t)&tss, sizeof(tss) - 1, TASK64_SEG); struct dtr64 gdtr = {sizeof(gdt) - 1, (uint64_t)&gdt}; @@ -123,10 +145,17 @@ static void gdt_init(void) // defined here. "lretq\n" ".flush:\n" + "ltr %w3\n" "popf\n" // dependency on pre-boot GDT is now gone - :: "m"(gdtr), "i"(CODE_SEG_INDEX << 3), "r"(DATA_SEG_INDEX << 3) + : + : "m"(gdtr), + "i"(CODE_SEG_INDEX << 3), + "r"(DATA_SEG_INDEX << 3), + "r"(TASK_SEG_INDEX << 3) ); + + } static void idt_init(void) |