From 74d19eb5a3695d56d9bcf1c1a8defb53ef1ec520 Mon Sep 17 00:00:00 2001 From: cuz Date: Sun, 27 Nov 2005 22:58:44 +0000 Subject: [PATCH] Added an extended memory driver for the DTV. git-svn-id: svn://svn.cc65.org/cc65/trunk@3674 b7a2c559-68d2-44c3-8de9-860c34a00d81 --- libsrc/c64/Makefile | 2 +- libsrc/c64/dtv-himem.s | 236 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 237 insertions(+), 1 deletion(-) create mode 100644 libsrc/c64/dtv-himem.s diff --git a/libsrc/c64/Makefile b/libsrc/c64/Makefile index 4771f79d7..ca0e27852 100644 --- a/libsrc/c64/Makefile +++ b/libsrc/c64/Makefile @@ -68,7 +68,7 @@ OBJS = _scrsize.o \ #-------------------------------------------------------------------------- # Drivers -EMDS = c64-georam.emd c64-ram.emd c64-ramcart.emd c64-reu.emd c64-vdc.emd +EMDS = c64-georam.emd c64-ram.emd c64-ramcart.emd c64-reu.emd c64-vdc.emd dtv-himem.emd JOYS = c64-hitjoy.joy c64-numpad.joy c64-ptvjoy.joy c64-stdjoy.joy diff --git a/libsrc/c64/dtv-himem.s b/libsrc/c64/dtv-himem.s new file mode 100644 index 000000000..2f65d2034 --- /dev/null +++ b/libsrc/c64/dtv-himem.s @@ -0,0 +1,236 @@ +; +; Extended memory driver for the C64 D2TV (the second or PAL version). +; Driver works without problems when statically linked. +; +; Ullrich von Bassewitz, 2005-11-27 +; + + .include "zeropage.inc" + + .include "em-kernel.inc" + .include "em-error.inc" + + + .macpack generic + + +; ------------------------------------------------------------------------ +; Header. Includes jump table + +.segment "JUMPTABLE" + +; Driver signature + + .byte $65, $6d, $64 ; "emd" + .byte EMD_API_VERSION ; EM API version number + +; Jump table. + + .word INSTALL + .word UNINSTALL + .word PAGECOUNT + .word MAP + .word USE + .word COMMIT + .word COPYFROM + .word COPYTO + +; ------------------------------------------------------------------------ +; Constants + +OP_COPYFROM = %00001101 +OP_COPYTO = %00001111 + +PAGES = (2048 - 128) * 4 + + +; ------------------------------------------------------------------------ +; Data. + +.bss +window: .res 256 ; Memory "window" + +.data + +; The MAP and COMMIT entries will actually call COPYFROM/COPYTO with +; a pointer to the following data structure: + +dma_params: .word window ; Host address + .byte 0 ; Offset in page +curpage: .word $0000 ; Page + .word .sizeof (window); # bytes to move, lo, hi + +.code + +; ------------------------------------------------------------------------ +; INSTALL routine. Is called after the driver is loaded into memory. If +; possible, check if the hardware is present and determine the amount of +; memory available. +; Must return an EM_ERR_xx code in a/x. +; + +INSTALL: + ldx #$FF + stx curpage+1 ; Invalidate curpage + inx ; X = 0 + txa ; A/X = EM_ERR_OK + rts + +; ------------------------------------------------------------------------ +; UNINSTALL routine. Is called before the driver is removed from memory. +; Can do cleanup or whatever. Must not return anything. +; + +UNINSTALL: + rts + + +; ------------------------------------------------------------------------ +; PAGECOUNT: Return the total number of available pages in a/x. +; + +PAGECOUNT: + lda #PAGES + rts + +; ------------------------------------------------------------------------ +; MAP: Map the page in a/x into memory and return a pointer to the page in +; a/x. The contents of the currently mapped page (if any) may be discarded +; by the driver. +; + +MAP: sta curpage + stx curpage+1 ; Remember the new page + + lda #dma_params + jsr COPYFROM ; Copy data into the window + + lda #window ; Return the window address +done: rts + +; ------------------------------------------------------------------------ +; USE: Tell the driver that the window is now associated with a given page. + +USE: sta curpage + stx curpage+1 ; Remember the page + lda #window ; Return the window + rts + +; ------------------------------------------------------------------------ +; COMMIT: Commit changes in the memory window to extended storage. + +COMMIT: lda curpage+1 ; Do we have a page mapped? + bmi done ; Jump if no page mapped + + lda #dma_params + +; Run into COPYTO + +; ------------------------------------------------------------------------ +; COPYTO: Copy from linear into extended memory. A pointer to a structure +; describing the request is passed in a/x. +; The function must not return anything. +; + +COPYTO: sta ptr1 + stx ptr1+1 ; Save the pointer + + ldx #OP_COPYTO ; Load the command + bne transfer + +; ------------------------------------------------------------------------ +; COPYFROM: Copy from extended into linear memory. A pointer to a structure +; describing the request is passed in a/x. +; The function must not return anything. +; + +COPYFROM: + sta ptr1 + stx ptr1+1 ; Save the pointer + + ldx #OP_COPYFROM + +; DTV DMA transfer routine. Expects the command in X. + +transfer: + lda #$01 ; Enable extended features + sta $d03f + +; Wait until the current DMA operation is finished + + jsr WAIT + +; Setup the source address. Carry is clear. + + ldy #EM_COPY::OFFS + lda (ptr1),y + sta $d300 + ldy #EM_COPY::PAGE + lda (ptr1),y + sta $d301 + iny + lda (ptr1),y + adc #$42 ; Always RAM, start at $20000 + sta $d302 + +; Setup the target address + + ldy #EM_COPY::BUF + lda (ptr1),y + sta $d303 + iny + lda (ptr1),y + sta $d304 + lda #$40 ; Always RAM, start at $00000 + sta $d305 + +; Source and target steps + + lda #$01 + ldy #$00 + sta $d306 + sty $d307 + sta $d308 + sty $d309 + +; Modulo disable + + sty $d31e + +; Length + + ldy #EM_COPY::COUNT + lda (ptr1),y + sta $d30a + iny + lda (ptr1),y + sta $d30b + +; Start DMA + + stx $d31f + +; Wait until DMA finished + + jsr WAIT + +; Disable access to the extended registers + + lda #$00 + sta $d03f + + rts + + +; ------------------------------------------------------------------------ +; Wait until DMA has finished + +WAIT: lda $d31f + lsr a + bcs WAIT + rts -- 2.39.5