- memset((char *)gdt->address, 0x0, gdt->size);
- desc = (struct desc_struct *)gdt->address;
-
- /* The first GDT is a dummy. */
- desc++;
-
- if (IS_ENABLED(CONFIG_X86_64)) {
- /* __KERNEL32_CS */
- desc->limit0 = 0xffff;
- desc->base0 = 0x0000;
- desc->base1 = 0x0000;
- desc->type = SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
- desc->s = DESC_TYPE_CODE_DATA;
- desc->dpl = 0;
- desc->p = 1;
- desc->limit1 = 0xf;
- desc->avl = 0;
- desc->l = 0;
- desc->d = SEG_OP_SIZE_32BIT;
- desc->g = SEG_GRANULARITY_4KB;
- desc->base2 = 0x00;
-
- desc++;
- } else {
- /* Second entry is unused on 32-bit */
- desc++;
- }
-
- /* __KERNEL_CS */
- desc->limit0 = 0xffff;
- desc->base0 = 0x0000;
- desc->base1 = 0x0000;
- desc->type = SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
- desc->s = DESC_TYPE_CODE_DATA;
- desc->dpl = 0;
- desc->p = 1;
- desc->limit1 = 0xf;
- desc->avl = 0;
-
- if (IS_ENABLED(CONFIG_X86_64)) {
- desc->l = 1;
- desc->d = 0;
- } else {
- desc->l = 0;
- desc->d = SEG_OP_SIZE_32BIT;
- }
- desc->g = SEG_GRANULARITY_4KB;
- desc->base2 = 0x00;
- desc++;
-
- /* __KERNEL_DS */
- desc->limit0 = 0xffff;
- desc->base0 = 0x0000;
- desc->base1 = 0x0000;
- desc->type = SEG_TYPE_DATA | SEG_TYPE_READ_WRITE;
- desc->s = DESC_TYPE_CODE_DATA;
- desc->dpl = 0;
- desc->p = 1;
- desc->limit1 = 0xf;
- desc->avl = 0;
- desc->l = 0;
- desc->d = SEG_OP_SIZE_32BIT;
- desc->g = SEG_GRANULARITY_4KB;
- desc->base2 = 0x00;
- desc++;
-
- if (IS_ENABLED(CONFIG_X86_64)) {
- /* Task segment value */
- desc->limit0 = 0x0000;
- desc->base0 = 0x0000;
- desc->base1 = 0x0000;
- desc->type = SEG_TYPE_TSS;
- desc->s = 0;
- desc->dpl = 0;
- desc->p = 1;
- desc->limit1 = 0x0;
- desc->avl = 0;
- desc->l = 0;
- desc->d = 0;
- desc->g = SEG_GRANULARITY_4KB;
- desc->base2 = 0x00;
- desc++;
- }
-
- asm volatile("cli");
- asm volatile ("lgdt %0" : : "m" (*gdt));
-