From d8ab00c7cde91bb54fdec62bb265bde56be849f4 Mon Sep 17 00:00:00 2001
From: mykola2312 <49044616+mykola2312@users.noreply.github.com>
Date: Sat, 3 Aug 2024 04:30:31 +0300
Subject: [PATCH] fixed stupid bug - mov msg, %si actually translated to move
 r/m16 to %si instead of immediate move like mov $msg, %si. also implemented
 bootloader migration to 0050:0000 address just to be stable

---
 src/mbr_test.s | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/mbr_test.s b/src/mbr_test.s
index a505820..4b1c00e 100644
--- a/src/mbr_test.s
+++ b/src/mbr_test.s
@@ -1,13 +1,31 @@
 .section .text
 .code16
 
-    mov $BOOTLOADER_SIZE, %ax
-
+    # we're moving to 0050, 0x7C00 -> 0x0500
+    # so, DS is 0x07C0 and ES is 0x0050  
     mov $0x07C0, %ax
     mov %ax, %ds
+    mov $0x0050, %ax
+    mov %ax, %es
 
-    mov msg, %si
+    # set both source and destination pointers to zero, since we using segments
+    xor %ax, %ax
+    mov %ax, %si
+    mov %ax, %di
+
+    # set counter with determined size by linker
+    mov $BOOTLOADER_SIZE, %cx
     cld
+.copy:
+    lodsb
+    stosb
+    loop .copy
+
+    # far jump to new memory region
+    jmp $0x0050,$.bootloader
+.bootloader:
+
+    mov $msg, %si
 .putc_loop:
     lodsb
     or %al, %al