diff options
Diffstat (limited to 'src/entry/definitions.asm')
| -rw-r--r-- | src/entry/definitions.asm | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/entry/definitions.asm b/src/entry/definitions.asm new file mode 100644 index 0000000..dcaa141 --- /dev/null +++ b/src/entry/definitions.asm @@ -0,0 +1,26 @@ +; MIT License, Copyright (c) 2021 Marvin Borner +; This file includes definitions to reduce magic numbers + +; Boot constants +%define LOCATION 0x7c00 ; Bootloader location +%define SECTOR_END_SIG 0xaa55 ; Bootsector end signature +%define SECTOR_SIZE 512 ; Bootsector size + +; Interrupts +%define SCREEN_INT 0x10 ; Screen/video BIOS interrupt +%define DISK_INT 0x13 ; Disk BIOS interrupt + +; Characters +%define NEWLINE 0x0A ; Newline character (\n) +%define RETURN 0x0D ; Return character (\r) +%define NULL 0x00 ; NULL character (\0) + +; Screen/video commands (for SCREEN_INT; using VGA interface) +%define SCREEN_CLEAR 0x03 ; Clear screen command +%define SCREEN_OUT 0x0e ; Screen output command + +; Disk commands +%define DISK_EXT_CHECK 0x41 ; Disk extension check command +%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 |