Clean up the reset stack macro further; incorporate segment reset

as well as enable interrupts.

3 files changed, 13 insertions, 14 deletions

diff --git a/abort.inc b/abort.inc
index f1773b5f..80d70ad6 100644
--- a/abort.inc
+++ b/abort.inc
@@ -46,11 +46,7 @@ abort_check:
 ;             SI    = offset (in _text) of error message to print
 ;
 abort_load:
-                mov ax,cs                       ; Restore CS = DS = ES
-                mov ds,ax
-                mov es,ax
-		RESET_STACK			; AX must = 0
-		sti
+		RESET_STACK_AND_SEGS AX
                 call cwritestr                  ; Expects SI -> error msg
 
 		; Return to the command prompt
diff --git a/comboot.inc b/comboot.inc
index 3e18b9d3..9a96326d 100644
--- a/comboot.inc
+++ b/comboot.inc
@@ -204,12 +204,7 @@ comboot_bogus:	cli			; Don't trust anyone
 comboot_exit:
 		mov bx,enter_command	; Normal return to command prompt
 comboot_exit_special:
-		xor ax,ax
-		mov ds,ax
-		mov es,ax
-		RESET_STACK		; AX must = 0
-		sti
-		cld
+		RESET_STACK_AND_SEGS AX
 		call adjust_screen	; The COMBOOT program might have changed the screen
 		jmp bx
 
diff --git a/stack.inc b/stack.inc
index f3ec26ec..47246e1c 100644
--- a/stack.inc
+++ b/stack.inc
@@ -20,11 +20,17 @@
 %define _STACK_INC
 
 ;
-; This macro resets the stack pointer.  It assumes CS == DS and AX == 0.
+; This macro resets the stack pointer, and sets CS == DS == ES == 0,
+; interrupts on, DF = 0.
 ;
-%macro RESET_STACK 0
+; It takes a 16-bit register that can be safely clobbered as parameter.
+;
+%macro RESET_STACK_AND_SEGS 1
+		xor %1,%1
+		mov ds,%1
+		mov es,%1
 %if IS_SYSLINUX || IS_EXTLINUX
-                mov ss,ax                       ; Just in case...
+                mov ss,%1                       ; Just in case...
                 mov sp,StackBuf-2*3    		; Reset stack
 %elif IS_PXELINUX
 		lss esp,[BaseStack]
@@ -33,6 +39,8 @@
 %else
 		NEED TO KNOW HOW TO RESET STACK
 %endif
+		sti
+		cld
 %endmacro
 
 %endif ; _STACK_INC