diff options
Diffstat (limited to 'src/entry/definitions.asm')
| -rw-r--r-- | src/entry/definitions.asm | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/entry/definitions.asm b/src/entry/definitions.asm index dcaa141..019eefa 100644 --- a/src/entry/definitions.asm +++ b/src/entry/definitions.asm @@ -24,3 +24,15 @@ %define DISK_EXT_CHECK_REQ 0x55aa ; First extension check signature (request) %define DISK_EXT_CHECK_RESP 0xaa55 ; Second extension check signature (response) %define DISK_READ 0x42 ; Disk extended read command + +; GDT constants (bitmap) +%define GDT_MAX_LIMIT 0xffff ; I just use the max limit lel +%define GDT_PRESENT 0b10000000 ; Is present +%define GDT_RING3 0b01100000 ; Privilege level 3 +%define GDT_DESCRIPTOR 0b00010000 ; Descriptor type, set for code/data +%define GDT_EXECUTABLE 0b00001000 ; Can be executed +%define GDT_READWRITE 0b00000010 ; Read/write access for code/data +%define GDT_ACCESSED 0b00000001 ; Whether segment is accessible +%define GDT_GRANULARITY 0x80 ; Page granularity (4KiB) +%define GDT_SIZE 0x40 ; Use 32 bit selectors +%define GDT_DATA_OFFSET 0x10 ; Offset to GDT data segment |