From f361ec5264f8b2655b76d7f69f25fd9c9957f530 Mon Sep 17 00:00:00 2001
From: "Chloe M." <chloe@aptel.org>
Date: Thu, 20 Aug 2026 07:16:51 +0000
Subject: boot/amd64: mbr: Add some feedback via serial out

Signed-off-by: Chloe M. <chloe@aptel.org>
---
 boot/arch/amd64/mbr/mbr.S | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'boot')

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
-- 
cgit v1.2.3