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

@@ -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