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some cleanup

This commit is contained in:
mrdudz 2022-07-21 03:43:54 +02:00
parent a55807f682
commit 86091ac6bf

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@ -3,49 +3,67 @@
;should work for ActionReplay as well...
;
;
;Version 1.0
;
;Johannes Braun 2006-08-22
;hannenz@freenet.de
; original Version 1.0 by Johannes Braun 2006-08-22 <hannenz@freenet.de>
;
;use the functions described in "usr/lib/cc65/include/em.h" to make use of this driver.
;-------------------------------------------------------------------------------------------------------------------------
; ------------------------------------------------------------------------
;NOTE: If called from ROM the Lo_Code routines must exit with LDA #$00 / STA $DE00!!! just change and recompile!
.include "em-kernel.inc"
.importzp ptr1,ptr2,ptr3,ptr4,tmp1
.macpack generic
.include "zeropage.inc"
c64_ram = ptr1 ;use some more expressive identifiers...
rr_ram = ptr2
len = ptr3
aux = ptr4
temp = tmp1
.include "em-kernel.inc"
.include "em-error.inc"
Lo_Mem = $0100 ;location of Lo_Code (must be below $1000 or above $e000)
.macpack generic
.macpack module
.segment "JUMPTABLE"
; ------------------------------------------------------------------------
.byte $65,$6d,$64 ;Driver signature
.byte EMD_API_VERSION
c64_ram = ptr1 ; use some more expressive identifiers...
rr_ram = ptr2
len = ptr3
aux = ptr4
temp = tmp1
.addr INSTALL ;Jump Table
.addr UNINSTALL
.addr PAGECOUNT
.addr MAP
.addr USE
.addr COMMIT
.addr COPYFROM
.addr COPYTO
Lo_Mem = $0100 ; location of Lo_Code (must be below $1000 or above $e000)
; ------------------------------------------------------------------------
; Header. Includes jump table
module_header _c64_rrr_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
; ------------------------------------------------------------------------
.bss
window: .res 256 ;the memory window (256 bytes)
window: .res 256 ; the memory window (256 bytes)
.rodata
dummy: .word window ;a "pseudo"-em_copy_struct, used by em_map/ em_commit
.byte 0 ;to pass over to COPYTO/COPYFROM
curpage: .byte $ff ;just this byte is changed according to the desired page
dummy:
.word window ; a "pseudo"-em_copy_struct, used by em_map/ em_commit
.byte 0 ; to pass over to COPYTO/COPYFROM
curpage:
.byte $ff ; just this byte is changed according to the desired page
.byte 0
.word 256
@ -61,37 +79,37 @@ INSTALL:
sta Lo_Mem,x
dex
bpl :-
stx curpage ;invalidate current page ($ff)
stx curpage ; invalidate current page ($ff)
ldx #$23 ;$de00 value for rr-ram
ldy #$02 ;$de00 value for c64-ram, CHANGE TO LDA #$00 if driver is called from ROM!
ldx #$23 ; $de00 value for rr-ram
ldy #$02 ; $de00 value for c64-ram, CHANGE TO LDA #$00 if driver is called from ROM!
bne COMMON
c1: stx $de00 ;try accessing rr-ram
c1: stx $de00 ; try accessing rr-ram
lda $8888
pha
lda $9999 ;remember old content of $8888 and $9999
lda $9999 ; remember old content of $8888 and $9999
pha
lda #$55
sta $8888 ;write test values
sta $8888 ; write test values
asl
sta $9999
sty $de00 ;switch to c64 ram
sty $de00 ; switch to c64 ram
stx $8888
stx $9999
stx $de00 ;switch to rr-ram again (if present)
ldx $8888 ;read the values
stx $de00 ; switch to rr-ram again (if present)
ldx $8888 ; read the values
ldy $9999
pla
sta $9999 ;and write the old values back
sta $9999 ; and write the old values back
pla
sta $8888
lda #2
sta $de00 ;c64 ram again
sta $de00 ; c64 ram again
cli
cpx #$55
@ -100,7 +118,7 @@ c1: stx $de00 ;try accessing rr-ram
bne no
lda #0
rts
no: asl ;.A still has #2, so return #4: error code for "device not present"
no: asl ; A still has #2, so return #4: error code for "device not present"
rts
c2:
;----------------------------------------------------------------------------------------
@ -108,7 +126,8 @@ c2:
;----------------------------------------------------------------------------------------
UNINSTALL:
return_null:
lda #$00 ;always return 32kb (128 pages)
lda #$00 ; always return 32kb (128 pages)
; fall through, skip the LDA
.byte $2c
;----------------------------------------------------------------------------------------
@ -123,12 +142,13 @@ PAGECOUNT:
;void* __fastcall__ em_use(unsigned page);
;----------------------------------------------------------------------------------------
USE:
cmp #$80 ;valid page?
bcs return_null ;no, return NULL pointer
sta curpage ;set to current page
return_win: lda #<window ;return pointer to window
cmp #$80 ; valid page?
bcs return_null ; no, return NULL pointer
sta curpage ; set to current page
return_win:
lda #<window ; return pointer to window
ldx #>window
return: rts
return: rts
;----------------------------------------------------------------------------------------
;void* __fastcall__ em_map(unsigned page);
@ -137,10 +157,10 @@ MAP:
cmp #$80
bcs return_null
sta curpage
lda #<dummy ;load .A/.X with adress of data for COPYFROM-call (which expects the
ldx #>dummy ;adress in .A/.X)
lda #<dummy ; load .A/.X with adress of data for COPYFROM-call (which expects the
ldx #>dummy ; adress in .A/.X)
jsr COPYFROM
bcs return_win ;function returns pointer to window (returns always with carry set!)
bcs return_win ; function returns pointer to window (returns always with carry set!)
;----------------------------------------------------------------------------------------
;void __fastcall__ em_commit(void);
@ -149,8 +169,8 @@ COMMIT:
lda curpage
cmp #$80
bcs return
lda #<dummy ;load .A/.X with adress of data for COPYTO-call (which expects the
ldx #>dummy ;adress in .A/.X)
lda #<dummy ; load .A/.X with adress of data for COPYTO-call (which expects the
ldx #>dummy ; adress in .A/.X)
;----------------------------------------------------------------------------------------
;void __fastcall__ em_copyto (struct em_copy *copy_data);
@ -161,7 +181,7 @@ COPYTO:
;copy the main copyto routine into Lo_Mem
ldy #Lo_Code1_End - Lo_Code1
: lda Lo_Code1-1,y
: lda Lo_Code1-1,y
sta Lo_Mem-1,y
dey
bne :-
@ -172,11 +192,11 @@ COMMON:
;this part will be executed in Lo_Mem (!) by COPYFROM
Lo_Code2:
stx $de00 ;map in rr-ram
lda (rr_ram),y ;get byte from rr-ram
sty $de00 ;RR-ROM will be mapped to $8000-$a000 but write access will go to c64-ram anyway!!
sta (c64_ram),y ;and write to c64-ram
nop ;pad to same size as Lo_Code1
stx $de00 ;map in rr-ram
lda (rr_ram),y ;get byte from rr-ram
sty $de00 ;RR-ROM will be mapped to $8000-$a000 but write access will go to c64-ram anyway!!
sta (c64_ram),y ;and write to c64-ram
nop ;pad to same size as Lo_Code1
nop
Lo_Code2_End:
@ -184,41 +204,41 @@ Lo_Code2_End:
;this part will be executed in Lo_Mem (!) by COPYTO
Lo_Code1:
lda (c64_ram),y ;read 1 byte from c64-ram
stx $de00 ;map in rr-ram
sta (rr_ram),y ;write byte to rr-ram
lda (c64_ram),y ;read 1 byte from c64-ram
stx $de00 ;map in rr-ram
sta (rr_ram),y ;write byte to rr-ram
lda #$02 ;map in c64-ram again
sta $de00
;12 bytes
;12 bytes
;this part is common for both COPYFROM/COPYTO and executed in Lo_Mem, too
Lo_Code_Common:
inc c64_ram ;increase pointers
inc c64_ram ;increase pointers
bne :+
inc c64_ram+1
: inc rr_ram
: inc rr_ram
bne @skip
inc rr_ram+1
lda rr_ram+1
cmp #$a0 ;wrap around 16k boundary in rr-ram window ($8000-$a000)
cmp #$a0 ;wrap around 16k boundary in rr-ram window ($8000-$a000)
bne @skip
lda #$80 ;reset pointer to $8000
lda #$80 ;reset pointer to $8000
sta rr_ram+1
txa ;adjust value in .X to map in next 16k-bank in rr-ram
adc #7 ;carry is set because of former CMP, so it adds 8
txa ;adjust value in .X to map in next 16k-bank in rr-ram
adc #7 ;carry is set because of former CMP, so it adds 8
tax
;27 bytes
@skip: lda c64_ram
@skip: lda c64_ram
cmp len
lda c64_ram+1
sbc len+1
bcc Lo_Code1
lda #2 ;CHANGE to LDA #0 if driver is called from ROM
lda #2 ;CHANGE to LDA #0 if driver is called from ROM
sta $de00
cli
rts ;17 bytes = 56 bytes Lo_Code ($38)
rts ;17 bytes = 56 bytes Lo_Code ($38)
Lo_Code1_End:
;----------------------------------------------------------------------------------------
;void __fastcall__ em_copyfrom(struct em_copy *copy_data);
@ -228,16 +248,16 @@ COPYFROM:
jsr get_struct_data
ldy #Lo_Code2_End - Lo_Code2 ;copy routine into Lo_Mem
: lda Lo_Code2-1,y
: lda Lo_Code2-1,y
sta Lo_Mem-1,y
dey
bne :-
ldy #Lo_Code1_End-Lo_Code_Common
: lda Lo_Code_Common-1,y
: lda Lo_Code_Common-1,y
sta Lo_Mem+11,y
dey
bne :-
beq COMMON ;and execute...
beq COMMON ;and execute...
;----------------------------------------------------------------------------------------
;read the struct data located at (.A/.X)
;and setup parameters for stash/ fetch operation
@ -247,39 +267,40 @@ get_struct_data:
;read and process the values from the em_copy struct passed to as parameters rameter to the
;functions em_copyto and em_copyfrom
sta aux ;store adress of struct (passed in .A/.X) into a zp pointer
sta aux ;store adress of struct (passed in .A/.X) into a zp pointer
stx aux+1
ldy #0 ;index 0
ldy #0 ;index 0
lda (aux),y ;read c64-adress lo
lda (aux),y ;read c64-adress lo
sta c64_ram
iny
lda (aux),y ;read c64-adress hi
sta c64_ram+1 ;(c64_ram) --> points to c64-adress space
lda (aux),y ;read c64-adress hi
sta c64_ram+1 ;(c64_ram) --> points to c64-adress space
iny
lda (aux),y ;read rr-adress lo
lda (aux),y ;read rr-adress lo
sta rr_ram
iny
lda (aux),y ;rr-adress hi
pha ;remember
lda (aux),y ;rr-adress hi
pha ;remember
and #$1f
ora #$80 ;adjust into 16k-window ($8000-$a000)
sta rr_ram+1
pla ;re-get hi byte of rr-adress
pla ;re-get hi byte of rr-adress
and #$60 ;isolate bits 5 and 6
lsr
lsr ;shift into bits 3 and 4
lsr ;shift into bits 3 and 4
ora #$23 ;set bit 5 (select ram) and 1+2 (game/exrom setting for ULTIMAX-mode)
tax ;.X has now the value to write into $de00 to acess rr-ram at desired 16k-bank
tax ;.X has now the value to write into $de00 to acess rr-ram at desired 16k-bank
iny
iny ;skip unused byte
lda (aux),y ;read length lo-byte
iny ;skip unused byte
lda (aux),y ;read length lo-byte
clc
adc c64_ram ;add to c64-addres
adc c64_ram ;add to c64-addres
sta len
iny
lda (aux),y ;length hi-byte
lda (aux),y ;length hi-byte
adc c64_ram+1
sta len+1 ;tmp2: length, tmp3 contains end adress of transfer in c64-ram.
rts ;55 bytes
sta len+1 ;tmp2: length, tmp3 contains end adress of transfer in c64-ram.
rts
;55 bytes