From: Duje Mihanović <duje.mihanovic@skole.hr>
Date: Tue, 22 Aug 2023 21:23:19 +0000 (+0200)
Subject: x86: mbr: Copy by dword during relocation
X-Git-Url: https://git.dujemihanovic.xyz/%7B%7B%20%24style.RelPermalink%20%7D%7D?a=commitdiff_plain;h=fb402cd052e9b9e9eaf30a7c14244a00e3cfe42a;p=nameless-os.git

x86: mbr: Copy by dword during relocation
---

diff --git a/boot/x86/mbr.s b/boot/x86/mbr.s
index b5d01c9..5319f4b 100644
--- a/boot/x86/mbr.s
+++ b/boot/x86/mbr.s
@@ -15,10 +15,10 @@ _start:
 
 	; perform self-relocation
 	cld
-	mov si, 0x7c00
-	mov di, 0x600
-	mov cx, 0x100 ; 256 words = 512 bytes
-	rep movsw
+	mov esi, 0x7c00
+	mov edi, 0x600
+	mov ecx, 0x80 ; 128 dwords = 512 bytes
+	rep movsd
 	; some BIOSes may set CS to 0x7c0, work around that
 	jmp 0:real_start
 real_start: