alexvoste
78 lines
2.1 KiB
C
78 lines
2.1 KiB
C
#ifndef GDT_H
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#define GDT_H
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#include <stdint.h>
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#define GDT_CODE_SEGMENT 0x08
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#define GDT_DATA_SEGMENT 0x10
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#define GDT_USER_DATA_SEGMENT 0x18
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#define GDT_USER_CODE_SEGMENT 0x20
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#define GDT_USER_DATA_RPL3 (GDT_USER_DATA_SEGMENT | 3)
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#define GDT_USER_CODE_RPL3 (GDT_USER_CODE_SEGMENT | 3)
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#define GDT_STAR_SYSRET_BASE GDT_DATA_SEGMENT
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#define GDT_STAR_SYSCALL_CS GDT_CODE_SEGMENT
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#define TSS_SELECTOR_BASE 0x28
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#define KERNEL_STACK_SIZE (4096 * 8)
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#define KERNEL_STACK_PAGES (KERNEL_STACK_SIZE / 0x1000)
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#define GDT_LIMIT_LOW(limit) (limit & 0xFFFF)
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#define GDT_BASE_LOW(base) (base & 0xFFFF)
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#define GDT_BASE_MIDDLE(base) ((base >> 16) & 0xFF)
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#define GDT_FLAGS_HI_LIMIT(limit, flags) \
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(((limit >> 16) & 0xF) | ((flags << 4) & 0xF0))
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#define GDT_BASE_HIGH(base) ((base >> 24) & 0xFF)
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#define GDT_ENTRY(base, limit, access, flags) \
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{GDT_LIMIT_LOW(limit), \
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GDT_BASE_LOW(base), \
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GDT_BASE_MIDDLE(base), \
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access, \
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GDT_FLAGS_HI_LIMIT(limit, flags), \
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GDT_BASE_HIGH(base)}
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typedef struct {
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uint32_t reserved0;
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uint64_t rsp0;
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uint64_t rsp1;
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uint64_t rsp2;
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uint64_t reserved1;
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uint64_t ist[7];
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uint64_t reserved2;
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uint32_t iobase;
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} __attribute__((packed)) tss_t;
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typedef struct {
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uint16_t limit_low;
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uint16_t base_low;
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uint8_t base_middle;
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uint8_t access;
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uint8_t limit_high_and_flags;
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uint8_t base_high;
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} __attribute__((packed)) gdt_entry_t;
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typedef struct {
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uint16_t limit_low;
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uint16_t base_low;
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uint8_t base_middle;
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uint8_t access;
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uint8_t limit_high_and_flags;
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uint8_t base_high;
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uint32_t base_higher;
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uint32_t zero;
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} __attribute__((packed)) tss_entry_t;
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typedef struct {
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uint16_t size;
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gdt_entry_t *pointer;
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} __attribute__((packed)) gdt_pointer_t;
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extern gdt_pointer_t gdtr;
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extern void load_tss(uint16_t sel);
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void gdt_init(void);
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void gdt_load(void);
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#endif |