diff options
Diffstat (limited to 'src/entry/bootsector.asm')
| -rw-r--r-- | src/entry/bootsector.asm | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/src/entry/bootsector.asm b/src/entry/bootsector.asm index 1beb850..c3532ee 100644 --- a/src/entry/bootsector.asm +++ b/src/entry/bootsector.asm @@ -139,6 +139,7 @@ dap: ; Disk Address Packet dd 0 ; More storage bytes ; Global Descriptor Table (GDT) +; There are better explanations for the constants in definitions.asm gdt: dw .size - 1 + 8 ; GDT size dd .start - 8 ; GDT start address @@ -147,16 +148,16 @@ gdt: dw 0xffff ; Limit dw 0x0000 ; Base (low 16 bits) db 0x00 ; Base (mid 8 bits) - db 10011010b ; Access - db 11001111b ; Granularity + db GDT_PRESENT | GDT_DESCRIPTOR | GDT_EXECUTABLE | GDT_READWRITE ; Access + db GDT_GRANULARITY | GDT_SIZE | 0xf ; Granularity db 0x00 ; Base (high 8 bits) ; Data dw 0xffff ; Limit dw 0x0000 ; Base (low 16 bits) db 0x00 ; Base (mid 8 bits) - db 10010010b ; Access - db 11001111b ; Granularity + db GDT_PRESENT | GDT_DESCRIPTOR | GDT_READWRITE ; Access; Data isn't executable + db GDT_GRANULARITY | GDT_SIZE | 0xf ; Granularity db 0x00 ; Base (high 8 bits) .end: .size: equ .end - .start |