mirror of
https://github.com/cc65/cc65.git
synced 2024-12-26 08:32:00 +00:00
377 lines
10 KiB
ArmAsm
377 lines
10 KiB
ArmAsm
;
|
|
; Extended memory driver for 65816 based extra RAM. Driver works without
|
|
; problems when statically linked.
|
|
;
|
|
; Marco van den Heuvel, 2015-12-01
|
|
;
|
|
|
|
.include "zeropage.inc"
|
|
|
|
.include "em-kernel.inc"
|
|
.include "em-error.inc"
|
|
|
|
|
|
.macpack generic
|
|
.macpack module
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table
|
|
|
|
module_header _c64_65816_emd
|
|
|
|
; Driver signature
|
|
|
|
.byte $65, $6d, $64 ; "emd"
|
|
.byte EMD_API_VERSION ; EM API version number
|
|
|
|
; Library reference
|
|
|
|
.addr $0000
|
|
|
|
; Jump table
|
|
|
|
.addr INSTALL
|
|
.addr UNINSTALL
|
|
.addr PAGECOUNT
|
|
.addr MAP
|
|
.addr USE
|
|
.addr COMMIT
|
|
.addr COPYFROM
|
|
.addr COPYTO
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Data.
|
|
|
|
.bss
|
|
isnotscpu: .res 1 ; SuperCPU not present
|
|
curpage: .res 1 ; Current page number
|
|
curbank: .res 1 ; Current bank number (+1)
|
|
bankcount: .res 1 ; Number of available banks (pages = banks * 256)
|
|
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:
|
|
sei
|
|
clc
|
|
sed
|
|
lda #$99
|
|
adc #$01 ; on 65C02, 65SC02, 65CE02, 65802 and 65816 sets the zero flag correctly
|
|
cld
|
|
bne @not_present
|
|
clc
|
|
.P816
|
|
sep #$01 ; nop #$01 on 65C02/65SC02 and lda ($01,s),y on 65CE02
|
|
.P02
|
|
bcc @not_present
|
|
lda $d0bc
|
|
and #$80
|
|
sta isnotscpu
|
|
lda $07e8
|
|
pha ; save value incase it was used somewhere else
|
|
ldx #$ff
|
|
@fillloop: ; fill from top (bank 255) to bottom
|
|
txa
|
|
pha
|
|
.P816
|
|
plb ; pull dbr
|
|
.P02
|
|
stx $07e8
|
|
dex
|
|
cpx #$ff
|
|
bne @fillloop
|
|
inx
|
|
@compareloop: ; check from bottom to top
|
|
txa
|
|
pha
|
|
.P816
|
|
plb
|
|
.P02
|
|
cmp $07e8
|
|
bne @found_pages
|
|
.P816
|
|
inc
|
|
.P02
|
|
sta $07e8
|
|
cmp $07e8
|
|
bne @found_pages
|
|
inx
|
|
bne @compareloop
|
|
@found_pages:
|
|
dex
|
|
lda #$00
|
|
pha
|
|
.P816
|
|
plb
|
|
.P02
|
|
pla
|
|
sta $07e8
|
|
cli
|
|
lda isnotscpu
|
|
bne @noextradex
|
|
dex
|
|
@noextradex:
|
|
stx bankcount
|
|
lda #<EM_ERR_OK
|
|
ldx #>EM_ERR_OK
|
|
rts
|
|
@not_present:
|
|
cli
|
|
lda #<EM_ERR_NO_DEVICE
|
|
ldx #>EM_ERR_NO_DEVICE
|
|
; 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 #$00 ; a whole bank is either usable or not
|
|
ldx bankcount
|
|
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 ; Remember the new page
|
|
stx curbank ; Remember the new bank
|
|
|
|
sta ptr2+1 ; src address low
|
|
lda #$00
|
|
sta ptr2 ; src address high
|
|
inx
|
|
ldy isnotscpu ; check if not scpu
|
|
bne @notscpu
|
|
inx
|
|
@notscpu:
|
|
stx tmp2 ; src bank
|
|
|
|
sta tmp1 ; dst bank
|
|
|
|
sta ptr3+1 ; length high
|
|
lda #$ff
|
|
sta ptr3 ; length low
|
|
|
|
lda #<window
|
|
sta ptr1 ; dst address low
|
|
ldx #>window
|
|
stx ptr1+1 ; dst address high
|
|
|
|
jsr transfer
|
|
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; USE: Tell the driver that the window is now associated with a given page.
|
|
|
|
USE: sta curpage ; Remember the page
|
|
stx curbank ; Remember the bank
|
|
lda #<window
|
|
ldx #>window ; Return the window
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; COMMIT: Commit changes in the memory window to extended storage.
|
|
|
|
COMMIT: lda curpage ; Get the current page
|
|
sta ptr1+1 ; dst high
|
|
ldx #$00
|
|
stx ptr1 ; dst low
|
|
|
|
lda #<window
|
|
sta ptr2 ; src low
|
|
lda #>window
|
|
sta ptr2+1 ; src high
|
|
|
|
stx ptr3+1 ; length high
|
|
lda #$ff
|
|
sta ptr3 ; length low
|
|
|
|
stx tmp2 ; src bank
|
|
ldy curbank ; Get the current bank
|
|
iny
|
|
ldx isnotscpu
|
|
bne @notascpu
|
|
iny
|
|
@notascpu:
|
|
sty tmp1 ; dst bank
|
|
|
|
jsr transfer
|
|
|
|
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:
|
|
sta ptr4
|
|
stx ptr4+1 ; Save the passed em_copy pointer
|
|
|
|
ldy #EM_COPY::COUNT+1 ; start at the end of the struct
|
|
lda (ptr4),y ; get high byte of count
|
|
tax
|
|
dey
|
|
lda (ptr4),y ; get low byte of count
|
|
bne @nodex
|
|
dex
|
|
@nodex:
|
|
.P816
|
|
dec
|
|
.P02
|
|
sta ptr3 ; length low
|
|
stx ptr3+1 ; length high
|
|
dey
|
|
lda (ptr4),y ; get bank
|
|
.P816
|
|
inc
|
|
.P02
|
|
ldx isnotscpu
|
|
bne @notscpu64
|
|
.P816
|
|
inc
|
|
.P02
|
|
@notscpu64:
|
|
sta tmp2 ; src bank
|
|
dey
|
|
lda (ptr4),y ; get page
|
|
sta ptr2+1 ; src high
|
|
dey
|
|
lda (ptr4),y ; get offset in page
|
|
sta ptr2 ; src low
|
|
dey
|
|
lda (ptr4),y ; get memory buffer high
|
|
sta ptr1+1 ; dst high
|
|
dey
|
|
lda (ptr4),y ; get memory buffer low
|
|
sta ptr1 ; dst low
|
|
lda #$00
|
|
sta tmp1 ; dst bank
|
|
|
|
jsr transfer
|
|
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; 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 ptr4
|
|
stx ptr4+1 ; Save the passed em_copy pointer
|
|
|
|
ldy #EM_COPY::COUNT+1 ; start at the end of the struct
|
|
lda (ptr4),y ; get high byte of count
|
|
tax
|
|
dey
|
|
lda (ptr4),y ; get low byte of count
|
|
bne @nodex2
|
|
dex
|
|
@nodex2:
|
|
.P816
|
|
dec
|
|
.P02
|
|
sta ptr3 ; length low
|
|
txa
|
|
sta ptr3+1 ; length high
|
|
dey
|
|
lda (ptr4),y ; get bank
|
|
.P816
|
|
inc
|
|
.P02
|
|
ldx isnotscpu
|
|
bne @notascpu64
|
|
.P816
|
|
inc
|
|
.P02
|
|
@notascpu64:
|
|
sta tmp1 ; dst bank
|
|
dey
|
|
lda (ptr4),y ; get page
|
|
sta ptr1+1 ; dst high
|
|
dey
|
|
lda (ptr4),y ; get page offset
|
|
sta ptr1 ; dst low
|
|
dey
|
|
lda (ptr4),y ; get memory buffer high
|
|
sta ptr2+1 ; src low
|
|
dey
|
|
lda (ptr4),y ; get memory buffer low
|
|
sta ptr2 ; src high
|
|
lda #$00
|
|
sta tmp2 ; src bank
|
|
|
|
jsr transfer
|
|
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Helper function for moving a block, the following is used:
|
|
; ptr1: dst
|
|
; ptr2: src
|
|
; ptr3: length
|
|
; tmp1: dst bank
|
|
; tmp2: src bank
|
|
|
|
transfer:
|
|
.P816
|
|
.A8
|
|
.I8
|
|
sei
|
|
pha
|
|
phx
|
|
phy
|
|
ldx tmp1 ; load srcbank
|
|
stx @move+1 ; store srcbank in move + 1
|
|
ldy tmp2 ; load dstbank
|
|
sty @move+2 ; store dstbank in move + 2
|
|
clc ; switch to native mode
|
|
xce
|
|
php ; save status bits
|
|
rep #%00110000 ; set A and index to 16bit
|
|
.A16
|
|
.I16
|
|
ldy ptr1
|
|
ldx ptr2
|
|
lda ptr3
|
|
@move:
|
|
mvn 0,0
|
|
plp ; restore status bits
|
|
.A8
|
|
.I8
|
|
lda #$00
|
|
pha
|
|
plb ; restore dbr
|
|
sec
|
|
xce ; switch to emul mode
|
|
ply
|
|
plx
|
|
pla
|
|
cli
|
|
rts
|
|
.P02
|