v65c816: DMA protection for disk DMA

diff --git a/Kernel/platform-v65c816/v65.s b/Kernel/platform-v65c816/v65.s
index f1fb654..fb40730 100644 (file)
--- a/Kernel/platform-v65c816/v65.s
+++ b/Kernel/platform-v65c816/v65.s
@@ -165,6 +165,9 @@ _hd_read_data:
        sta hd_rpatch+1         ; destination is bank we want
        phb                     ; bank will be corrupted
 
+       lda  #$34               ; DMA port
+       sta f:$00FE11           ; point it at the disk port
+
        rep #$30
        .a16
 
@@ -172,9 +175,13 @@ _hd_read_data:
 hd_rpatch:
        mvn $FF,$FF
        plb
-       sep #$30
+       sep #$30                ; go anywhere
        .a8
        .i8
+
+       lda #0
+       sta f:$00FE11           ; ensure any DMA window I/O doesn't
+
        rts
 
 _hd_write_data:
@@ -188,6 +195,10 @@ _hd_write_data:
                                ; (range all maps to disk I/O port)
        lda _hd_kmap
        sta hd_wpatch+2         ; source is bank we want
+
+       lda  #$34               ; DMA port
+       sta f:$00FE11           ; point it at the disk port
+
        phb                     ; bank will be corrupted
 
        rep #$30
@@ -198,9 +209,13 @@ _hd_write_data:
 hd_wpatch:
        mvn $FF,$FF
        plb
-       sep #$30
+       sep #$30                ; go anywhere
        .a8
        .i8
+
+       lda #0
+       sta f:$00FE11           ; ensure any DMA window I/O doesn't
+
        rts
 
 _hd_kmap: