msx1: fix register trashing bugs in the map logic

diff --git a/Kernel/platform-msx1/slots.s b/Kernel/platform-msx1/slots.s
index 7618eb1..e656624 100644 (file)
--- a/Kernel/platform-msx1/slots.s
+++ b/Kernel/platform-msx1/slots.s
@@ -289,7 +289,9 @@ map_save_kernel:
        pop bc
        pop de
        pop hl
+       push af
        call map_kernel_di              ; FIXME: fast path this later
+       pop af
        ret
 
 ;
@@ -327,6 +329,7 @@ was_di:
 
 map_kernel_di:
        push af
+       push hl
        xor a
        ld (map_id),a
        ; We are possibly coming from a user bank. We need to jam the
@@ -338,6 +341,7 @@ map_kernel_di:
        out (0xA8),a
        ld hl,#_kernel_map
        call _switch_map
+       pop hl
        pop af
        ret
 
@@ -360,10 +364,12 @@ map_process_always:
 
 map_process_always_di:
        push af
+       push hl
        ld a,#1
        ld (map_id),a
        ld hl,#_user_map
        call _switch_map
+       pop hl
        pop af
        ret