writestr_early: save/restore registers

We have made it this far without it, but it seems like a disaster
waiting to happen.  We can afford the extra four bytes in sector 1.

diff --git a/core/extlinux.asm b/core/extlinux.asm
index 087fc3c..c416541 100644 (file)
--- a/core/extlinux.asm
+++ b/core/extlinux.asm
@@ -692,6 +692,7 @@ verify_checksum:
 ;           messages, so it should be OK.
 ;
 writestr_early:
+               pushad
 .loop:         lodsb
                and al,al
                 jz .return
@@ -699,7 +700,8 @@ writestr_early:
                mov bx,0007h            ; Attribute
                int 10h
                jmp short .loop
-.return:       ret
+.return:       popad
+               ret
 
 
 ; getlinsecsr: save registers, call getlinsec, restore registers

diff --git a/core/ldlinux.asm b/core/ldlinux.asm
index 193bb06..5a205c0 100644 (file)
--- a/core/ldlinux.asm
+++ b/core/ldlinux.asm
@@ -712,6 +712,7 @@ verify_checksum:
 ;           messages, so it should be OK.
 ;
 writestr_early:
+               pushad
 .loop:         lodsb
                and al,al
                 jz .return
@@ -719,7 +720,8 @@ writestr_early:
                mov bx,0007h            ; Attribute
                int 10h
                jmp short .loop
-.return:       ret
+.return:       popad
+               ret
 
 
 ; getlinsecsr: save registers, call getlinsec, restore registers