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Kernel: Add Other GDT entries to x86_64

This commit is contained in:
Bananymous 2023-01-26 12:53:04 +02:00
parent f0093ed2fd
commit 6418d7cfc3
1 changed files with 18 additions and 2 deletions
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20
kernel/arch/x86_64/boot.S
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@ -10,6 +10,19 @@
.set PG_READ_WRITE, 1<<1
.set PG_PAGE_SIZE, 1<<7
# GDT access byte
.set GDT_A_A, 1<<40
.set GDT_A_RW, 1<<41
.set GDT_A_DC, 1<<42
.set GDT_A_E, 1<<43
.set GDT_A_S, 1<<44
.set GDT_A_DPL, 1<<45
.set GDT_A_P, 1<<47
# GDT flags
.set GDT_F_L, 1<<53
.set GDT_F_DB, 1<<54
.set GDT_F_G, 1<<55
.code32
# Multiboot header
@ -60,8 +73,11 @@ g_multiboot_magic:
.skip 8
boot_gdt:
.quad 0 // null
.quad (1<<53) | (1<<47) | (1<<44) | (1<<43) // kernel code P,S,E,L (present, code/data, executable, long mode)
.quad 0 # null descriptor
.quad (GDT_F_G | GDT_F_L ) | (GDT_A_P | (0 * GDT_A_DPL) | GDT_A_S | GDT_A_E | GDT_A_RW) | (0xF << 48 | 0xFFFF) # kernel code
.quad (GDT_F_G | GDT_F_DB ) | (GDT_A_P | (0 * GDT_A_DPL) | GDT_A_S | GDT_A_RW) | (0xF << 48 | 0xFFFF) # kernel data
.quad (GDT_F_G | GDT_F_L ) | (GDT_A_P | (3 * GDT_A_DPL) | GDT_A_S | GDT_A_E | GDT_A_RW) | (0xF << 48 | 0xFFFF) # userspace code
.quad (GDT_F_G | GDT_F_DB ) | (GDT_A_P | (3 * GDT_A_DPL) | GDT_A_S | GDT_A_RW) | (0xF << 48 | 0xFFFF) # userspace data
boot_gdtr:
.short . - boot_gdt - 1
.quad boot_gdt