mirror of
https://github.com/cc65/cc65.git
synced 2025-01-28 00:30:12 +00:00
New extended memory driver for the C256K memory extension. Written and
contributed by Marco van den Heuvel with several changes by me. git-svn-id: svn://svn.cc65.org/cc65/trunk@4577 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
uz
parent
074cd57d84
commit
37fbe08df2
@ -165,6 +165,10 @@ configuration.
|
||||
|
||||
<descrip>
|
||||
|
||||
<tag><tt/c64-c256k.emd/</tag>
|
||||
A driver for the C64 256K memory expansion. This driver offers 768 pages of
|
||||
256 bytes each. Written and contributed by Marco van den Heuvel.
|
||||
|
||||
<tag><tt/c64-georam.emd/</tag>
|
||||
A driver for the Berkeley Softworks GeoRam cartridge. The driver will
|
||||
determine the available RAM from the connected cartridge. It supports 64KB
|
||||
|
||||
@ -71,7 +71,8 @@ OBJS = _scrsize.o \
|
||||
#--------------------------------------------------------------------------
|
||||
# Drivers
|
||||
|
||||
EMDS = c64-georam.emd \
|
||||
EMDS = c64-c256k.emd \
|
||||
c64-georam.emd \
|
||||
c64-isepic.emd \
|
||||
c64-ram.emd \
|
||||
c64-ramcart.emd \
|
||||
|
||||
506
libsrc/c64/c64-c256k.s
Executable file
506
libsrc/c64/c64-c256k.s
Executable file
@ -0,0 +1,506 @@
|
||||
;
|
||||
; Extended memory driver for the C256K memory expansion
|
||||
; Marco van den Heuvel, 2010-01-27
|
||||
;
|
||||
|
||||
.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
|
||||
|
||||
BASE = $4000
|
||||
PAGES = 3 * 256
|
||||
CHECKC256K = $0200
|
||||
TRANSFERC256K = $0200
|
||||
STASHOPCODE = $91
|
||||
pia = $DFC0
|
||||
|
||||
; ------------------------------------------------------------------------
|
||||
; Data.
|
||||
|
||||
.data
|
||||
|
||||
|
||||
; This function is used to copy code from and to the extended memory
|
||||
.proc c256kcopycode
|
||||
.org ::TRANSFERC256K ; Assemble for target location
|
||||
stx pia
|
||||
::STASHC256K := * ; Location and opcode is patched at runtime
|
||||
::VECC256K := *+1
|
||||
lda ($00),y
|
||||
ldx #$dc
|
||||
stx pia
|
||||
rts
|
||||
.reloc
|
||||
.endproc
|
||||
|
||||
; This function is used to check for the existence of the extended memory
|
||||
.proc c256kcheckcode
|
||||
.org ::CHECKC256K
|
||||
ldy #$00 ; Assume hardware not present
|
||||
|
||||
lda #$fc
|
||||
sta pia
|
||||
lda $01
|
||||
tax
|
||||
and #$f8
|
||||
sta $01
|
||||
lda $4000
|
||||
cmp $c000
|
||||
bne done ; Jump if not found
|
||||
inc $c000
|
||||
cmp $4000
|
||||
beq done ; Jump if not found
|
||||
|
||||
; Hardware is present
|
||||
iny
|
||||
done: stx $01
|
||||
ldx #$dc
|
||||
stx pia
|
||||
rts
|
||||
.reloc
|
||||
.endproc
|
||||
|
||||
; Since the functions above are copied to $200, the current contents of this
|
||||
; memory area must be saved into backup storage. Calculate the amount of
|
||||
; space necessary.
|
||||
.if .sizeof (c256kcopycode) > .sizeof (c256kcheckcode)
|
||||
backupspace = .sizeof (c256kcopycode)
|
||||
.else
|
||||
backupspace = .sizeof (c256kcheckcode)
|
||||
.endif
|
||||
|
||||
|
||||
.bss
|
||||
|
||||
curpage: .res 2 ; Current page number
|
||||
curbank: .res 1 ; Current bank
|
||||
backup: .res backupspace ; Backup area of data in the location
|
||||
; where the copy and check routines will be
|
||||
window: .res 256 ; Memory "window"
|
||||
|
||||
|
||||
.code
|
||||
; ------------------------------------------------------------------------
|
||||
; INSTALL routine. Is called after the driver is loaded into memory. If
|
||||
; possible, check if the hardware is present and determine the amount of
|
||||
; memory available.
|
||||
; Must return an EM_ERR_xx code in a/x.
|
||||
;
|
||||
|
||||
INSTALL:
|
||||
lda pia+1 ; Select Peripheral Registers
|
||||
ora #4
|
||||
sta pia+1
|
||||
tax
|
||||
lda pia+3
|
||||
ora #4
|
||||
sta pia+3
|
||||
tay
|
||||
|
||||
lda #$DC ; Set the default memory bank data
|
||||
sta pia
|
||||
lda #$FE
|
||||
sta pia+2
|
||||
|
||||
txa ; Select Data Direction Registers
|
||||
and #$FB
|
||||
sta pia+1
|
||||
tya
|
||||
and #$FB
|
||||
sta pia+3
|
||||
|
||||
lda #$FF ; Set the ports to output
|
||||
sta pia
|
||||
sta pia+2
|
||||
|
||||
txa
|
||||
and #$C7
|
||||
ora #$30 ; Set CA1 and
|
||||
sta pia+1 ; select Peripheral Registers
|
||||
sty pia+3
|
||||
|
||||
jsr backup_and_setup_check_routine
|
||||
jsr CHECKC256K
|
||||
cli
|
||||
ldx #$29
|
||||
jsr restore_data
|
||||
cpy #$01
|
||||
beq @present
|
||||
lda #<EM_ERR_NO_DEVICE
|
||||
ldx #>EM_ERR_NO_DEVICE
|
||||
rts
|
||||
|
||||
@present:
|
||||
lda #<EM_ERR_OK
|
||||
ldx #>EM_ERR_OK
|
||||
; rts ; Run into UNINSTALL instead
|
||||
|
||||
; ------------------------------------------------------------------------
|
||||
; 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
|
||||
ldx #>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:
|
||||
sei
|
||||
sta curpage ; Remember the new page
|
||||
stx curpage+1
|
||||
jsr adjust_page_and_bank
|
||||
stx curbank
|
||||
clc
|
||||
adc #>BASE
|
||||
sta ptr1+1
|
||||
ldy #0
|
||||
sty ptr1
|
||||
jsr backup_and_setup_copy_routine
|
||||
ldx #<ptr1
|
||||
stx VECC256K
|
||||
@L1:
|
||||
ldx curbank
|
||||
jsr TRANSFERC256K
|
||||
ldx ptr1
|
||||
sta window,x
|
||||
inc ptr1
|
||||
bne @L1
|
||||
|
||||
; Return the memory window
|
||||
|
||||
ldx #$0A
|
||||
jsr restore_data
|
||||
lda #<window
|
||||
ldx #>window ; Return the window address
|
||||
cli
|
||||
rts
|
||||
|
||||
; ------------------------------------------------------------------------
|
||||
; USE: Tell the driver that the window is now associated with a given page.
|
||||
|
||||
USE: sta curpage ; Remember the page
|
||||
stx curpage+1
|
||||
lda #<window
|
||||
ldx #>window ; Return the window
|
||||
rts
|
||||
|
||||
; ------------------------------------------------------------------------
|
||||
; COMMIT: Commit changes in the memory window to extended storage.
|
||||
|
||||
COMMIT:
|
||||
sei
|
||||
lda curpage ; Get the current page
|
||||
ldx curpage+1
|
||||
|
||||
jsr adjust_page_and_bank
|
||||
stx curbank
|
||||
clc
|
||||
adc #>BASE
|
||||
sta ptr1+1
|
||||
ldy #0
|
||||
sty ptr1
|
||||
jsr backup_and_setup_copy_routine
|
||||
ldx #<ptr1
|
||||
stx VECC256K
|
||||
ldx #<STASHOPCODE
|
||||
stx STASHC256K
|
||||
@L1:
|
||||
ldx ptr1
|
||||
lda window,x
|
||||
ldx curbank
|
||||
jsr TRANSFERC256K
|
||||
inc ptr1
|
||||
bne @L1
|
||||
|
||||
; Return the memory window
|
||||
|
||||
ldx #$0A
|
||||
jsr restore_data
|
||||
done:
|
||||
cli
|
||||
rts
|
||||
|
||||
; ------------------------------------------------------------------------
|
||||
; 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:
|
||||
sei
|
||||
jsr setup
|
||||
jsr backup_and_setup_copy_routine
|
||||
|
||||
; Setup is:
|
||||
;
|
||||
; - ptr1 contains the struct pointer
|
||||
; - ptr2 contains the linear memory buffer
|
||||
; - ptr3 contains -(count-1)
|
||||
; - ptr4 contains the page memory buffer plus offset
|
||||
; - tmp1 contains zero (to be used for linear memory buffer offset)
|
||||
; - tmp2 contains the bank value
|
||||
|
||||
lda #<ptr4
|
||||
sta VECC256K
|
||||
jmp @L3
|
||||
|
||||
@L1:
|
||||
ldx tmp2
|
||||
ldy #0
|
||||
jsr TRANSFERC256K
|
||||
ldy tmp1
|
||||
sta (ptr2),y
|
||||
inc tmp1
|
||||
bne @L2
|
||||
inc ptr2+1
|
||||
@L2:
|
||||
inc ptr4
|
||||
beq @L4
|
||||
|
||||
; Bump count and repeat
|
||||
|
||||
@L3:
|
||||
inc ptr3
|
||||
bne @L1
|
||||
inc ptr3+1
|
||||
bne @L1
|
||||
ldx #$0A
|
||||
jsr restore_data
|
||||
cli
|
||||
rts
|
||||
|
||||
; Bump page register
|
||||
|
||||
@L4:
|
||||
inc ptr4+1
|
||||
lda ptr4+1
|
||||
cmp #$80
|
||||
bne @L3
|
||||
lda #>BASE
|
||||
sta ptr4+1
|
||||
lda tmp2
|
||||
clc
|
||||
adc #$10
|
||||
sta tmp2
|
||||
jmp @L3
|
||||
|
||||
; ------------------------------------------------------------------------
|
||||
; 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:
|
||||
sei
|
||||
jsr setup
|
||||
jsr backup_and_setup_copy_routine
|
||||
|
||||
; Setup is:
|
||||
;
|
||||
; - ptr1 contains the struct pointer
|
||||
; - ptr2 contains the linear memory buffer
|
||||
; - ptr3 contains -(count-1)
|
||||
; - ptr4 contains the page memory buffer plus offset
|
||||
; - tmp1 contains zero (to be used for linear memory buffer offset)
|
||||
; - tmp2 contains the bank value
|
||||
|
||||
lda #<ptr4
|
||||
sta VECC256K
|
||||
lda #<STASHOPCODE
|
||||
sta STASHC256K
|
||||
jmp @L3
|
||||
|
||||
@L1:
|
||||
ldy tmp1
|
||||
lda (ptr2),y
|
||||
ldx tmp2
|
||||
ldy #0
|
||||
jsr TRANSFERC256K
|
||||
inc tmp1
|
||||
bne @L2
|
||||
inc ptr2+1
|
||||
@L2:
|
||||
inc ptr4
|
||||
beq @L4
|
||||
|
||||
; Bump count and repeat
|
||||
|
||||
@L3:
|
||||
inc ptr3
|
||||
bne @L1
|
||||
inc ptr3+1
|
||||
bne @L1
|
||||
ldx #$0A
|
||||
jsr restore_data
|
||||
cli
|
||||
rts
|
||||
|
||||
; Bump page register
|
||||
|
||||
@L4:
|
||||
inc ptr4+1
|
||||
lda ptr4+1
|
||||
cmp #$80
|
||||
bne @L3
|
||||
lda #>BASE
|
||||
sta ptr4+1
|
||||
lda tmp2
|
||||
clc
|
||||
adc #$10
|
||||
sta tmp2
|
||||
jmp @L3
|
||||
|
||||
; ------------------------------------------------------------------------
|
||||
; Helper function for COPYFROM and COPYTO: Store the pointer to the request
|
||||
; structure and prepare data for the copy
|
||||
|
||||
setup:
|
||||
sta ptr1
|
||||
stx ptr1+1 ; Save passed pointer
|
||||
|
||||
; Get the page number from the struct and adjust it so that it may be used
|
||||
; with the hardware. That is: ptr4 has the page address and page offset
|
||||
; tmp2 will hold the bank value
|
||||
|
||||
ldy #EM_COPY::PAGE+1
|
||||
lda (ptr1),y
|
||||
tax
|
||||
ldy #EM_COPY::PAGE
|
||||
lda (ptr1),y
|
||||
jsr adjust_page_and_bank
|
||||
clc
|
||||
adc #>BASE
|
||||
sta ptr4+1
|
||||
stx tmp2
|
||||
|
||||
; Get the buffer pointer into ptr2
|
||||
|
||||
ldy #EM_COPY::BUF
|
||||
lda (ptr1),y
|
||||
sta ptr2
|
||||
iny
|
||||
lda (ptr1),y
|
||||
sta ptr2+1
|
||||
|
||||
; Get the count, calculate -(count-1) and store it into ptr3
|
||||
|
||||
ldy #EM_COPY::COUNT
|
||||
lda (ptr1),y
|
||||
eor #$FF
|
||||
sta ptr3
|
||||
iny
|
||||
lda (ptr1),y
|
||||
eor #$FF
|
||||
sta ptr3+1
|
||||
|
||||
; Get the page offset into ptr4 and clear tmp1
|
||||
|
||||
ldy #EM_COPY::OFFS
|
||||
lda (ptr1),y
|
||||
sta ptr4
|
||||
lda #0
|
||||
sta tmp1
|
||||
|
||||
; Done
|
||||
|
||||
rts
|
||||
|
||||
; Helper routines for copying to and from the +256k ram
|
||||
|
||||
backup_and_setup_copy_routine:
|
||||
ldx #.sizeof (c256kcopycode) - 1
|
||||
@L1:
|
||||
lda TRANSFERC256K,x
|
||||
sta backup,x
|
||||
lda c256kcopycode,x
|
||||
sta TRANSFERC256K,x
|
||||
dex
|
||||
bpl @L1
|
||||
rts
|
||||
|
||||
backup_and_setup_check_routine:
|
||||
ldx #.sizeof (c256kcheckcode) - 1
|
||||
@L1:
|
||||
lda CHECKC256K,x
|
||||
sta backup,x
|
||||
lda c256kcheckcode,x
|
||||
sta CHECKC256K,x
|
||||
dex
|
||||
bpl @L1
|
||||
rts
|
||||
|
||||
restore_data:
|
||||
lda backup,x
|
||||
sta CHECKC256K,x
|
||||
dex
|
||||
bpl restore_data
|
||||
rts
|
||||
|
||||
; Helper routine to correct for the bank and page
|
||||
adjust_page_and_bank:
|
||||
sta tmp4
|
||||
lda #$0C
|
||||
sta tmp3
|
||||
lda tmp4
|
||||
and #$c0
|
||||
lsr
|
||||
lsr
|
||||
ora tmp3
|
||||
sta tmp3
|
||||
txa
|
||||
asl
|
||||
asl
|
||||
asl
|
||||
asl
|
||||
asl
|
||||
asl
|
||||
ora tmp3
|
||||
tax
|
||||
lda tmp4
|
||||
and #$3f
|
||||
rts
|
||||
Loading…
x
Reference in New Issue
Block a user