Fixup possible register clobbering

2 files changed, 11 insertions, 3 deletions

diff --git a/console.asm b/console.asm
index 8c880f3..de4fdb7 100644
--- a/console.asm
+++ b/console.asm
@@ -32,6 +32,7 @@ putc:
 
 
 console_scroll_up:
+	pusha
 	cmp dh, MAX_ROWS - 1
 	jne .no_action
 
@@ -50,12 +51,14 @@ console_scroll_up:
 	mov     dh, MAX_ROWS   ; lower row.
 	int     10h
 .no_action:
+	popa
 	ret
 
 
 console_driver:
 	push bp
 	mov bp, sp
+	pusha
 
 	call console_cursor_getpos
 	mov dh, [cursor_row]
@@ -143,9 +146,9 @@ console_driver:
 	call setcursor
 	add sp, 2
 
-
 .return_noupdate:
 	call console_scroll_up
+	popa
 	mov sp, bp
 	pop bp
 	ret
diff --git a/stdio.asm b/stdio.asm
index b4b54a4..35f4cd6 100644
--- a/stdio.asm
+++ b/stdio.asm
@@ -29,9 +29,11 @@ puts:
 printi:
 	push bp
 	mov bp, sp
+	push ax
 	mov ax, [bp + 4]
 	call putint
 .return:
+	pop ax
 	mov sp, bp
 	pop bp
 	ret
@@ -55,8 +57,8 @@ printh:
 puthex:
 	push ax
 	push bx
-	push dx
 	push cx
+	push dx
 
 	; ax is integer to print
 	ror ah, 4		; reverse hex value
@@ -91,8 +93,8 @@ puthex:
 		jne .divide
 
 .return:
-	pop cx
 	pop dx
+	pop cx
 	pop bx
 	pop ax
 	ret
@@ -141,6 +143,8 @@ printf:
 	mov bp, sp
 
 	mov di, bp		; save base pointer address
+	push di
+
 	mov bx, [bp + 4]	; format string address
 	add bp, 6		; set base pointer to beginning of '...' args
 
@@ -234,6 +238,7 @@ printf:
 					; a procedure modifies DI without restoring
 					; it, we're doomed; we'll roll right off the
 					; edge into oblivion.
+	pop di
 	mov sp, bp
 	pop bp
 	ret