px4plus: add memory open/close for sidecar

diff --git a/Kernel/platform-px4plus/swapdev.s b/Kernel/platform-px4plus/swapdev.s
index cc36abf..228b6e4 100644 (file)
--- a/Kernel/platform-px4plus/swapdev.s
+++ b/Kernel/platform-px4plus/swapdev.s
@@ -17,9 +17,6 @@
 ;      the I/O memory that held the bank we switched to, and then we fix
 ;      up the table. That makes all the magic going on conveniently
 ;      invisible to the core code.
-;
-;      FIXME: The 128K sidecar has a notion of open/closed. Open allows
-;      accesses, closes saves power. We need to support this.
 ;
 
                .globl _cartridge_copy
@@ -163,7 +160,12 @@ _sidecar_copy:
                push bc
                push de
                push hl
-               and #0x7F       ; strip the magic bit for the bank code
+               ld d, a         ; save bank
+               in a, (0x94)
+               or #0x02        ; memory power save off
+               out (0x94), a
+               ld a, #0x7F     ; strip the magic bit for the bank code
+               and d
                ld e, #0
                rra
                rl e
@@ -180,6 +182,9 @@ sidecar_cnext:
                inc e           ; next page
                dec d           ; count of pages to do
                jr nz, sidecar_cnext
+               in a, (0x94)
+               and #0xFD       ; memory power save on
+               out (0x94), a
                pop hl
                pop de
                pop bc
@@ -194,7 +199,12 @@ _sidecar_exchange:
                push bc
                push de
                push hl
-               and #0x7F       ; strip the magic bit for the bank code
+               ld d, a         ; save bank
+               in a, (0x94)
+               or #0x02        ; power save off
+               out (0x94), a
+               ld a, #0x7F     ; strip the magic bit for the bank code
+               and d
                ld e, #0
                rra
                rl e
@@ -223,6 +233,9 @@ sidecar_xnl:
                inc e           ; next page
                dec d           ; count of pages to do
                jr nz, sidecar_xnext
+               in a, (0x94)
+               and #0xFD       ; memory power save on
+               out (0x94), a
                pop hl
                pop de
                pop bc
@@ -292,6 +305,12 @@ _read_from_bank:   ; (page, dptr, buf) always 128 bytes
                ;
                ; Pull it from the sidecar (0x80-0x83)
                ;
+               ld d, a                 ; save bank
+               in a, (0x94)
+               or #0x02                ; power save off
+               out (0x94), a
+               ld a, #0x7F             ; strip the magic bit for the bank code
+               and d
                ld b, #0
                rra                     ; effectively multiply by 32768
                rr b                    ; 0x0 or 0x80
@@ -308,6 +327,9 @@ _read_from_bank:    ; (page, dptr, buf) always 128 bytes
                ld bc, #0x8093          ; 128 count, port 92)
                ld hl, (_romd_addr)
                inir                    ; 128 bytes into hl
+               in a, (0x94)
+               and #0xFD               ; memory power save on
+               out (0x94), a
                ret
 ;
 ;              2 is the low 32K, 3 the high