diff options
| author | Chloe M. <chloe@aptel.org> | 2026-08-20 07:16:51 +0000 |
|---|---|---|
| committer | Chloe M. <chloe@aptel.org> | 2026-08-20 07:22:52 +0000 |
| commit | f361ec5264f8b2655b76d7f69f25fd9c9957f530 (patch) | |
| tree | 91b0b176ae6832689e0136f7570fcb0dd69e93f2 /boot/arch/amd64/mbr/mbr.S | |
| parent | 6d606dbd3d39e7a1dc1315822f8b8e57f9e44992 (diff) | |
boot/amd64: mbr: Add some feedback via serial out
Signed-off-by: Chloe M. <chloe@aptel.org>
Diffstat (limited to 'boot/arch/amd64/mbr/mbr.S')
| -rw-r--r-- | boot/arch/amd64/mbr/mbr.S | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/boot/arch/amd64/mbr/mbr.S b/boot/arch/amd64/mbr/mbr.S index fa33707..a548ce7 100644 --- a/boot/arch/amd64/mbr/mbr.S +++ b/boot/arch/amd64/mbr/mbr.S @@ -35,11 +35,43 @@ reloc: /* Set our stack */ mov $0x7C00, %sp + /* Write out our boot string */ + mov $boot_msg, %si + call putstr + cli hlt jmp reloc +/* + * Write a string to the console + * + * %si: String to write + * + * XXX: Clobbers %AL + */ +putstr: + lodsb + or %al, %al + jz 1f + call putchr + jmp putstr +1: ret + +/* + * Write a single character to the console + * + * %al: Character to write + */ +putchr: + push %dx + mov $0x3F8, %dx + out %al, %dx + pop %dx + ret + drive_num: .byte 0x00 +boot_msg: .ascii "booting\0" .org 510 .byte 0x55 |