GSCats/loader.s
2023-08-06 15:55:42 -07:00

450 lines
6.6 KiB
ArmAsm

;
; loader
; A very simplistic code loader designed to manage
; GS code under ProDOS 8 (if it's good enough for Will Harvey...)
;
; Created by Quinn Dunki on 7/29/17
;
.a16
.i16
.include "equates.s"
.include "macros.s"
LOADBUFFER = $1100 ; Clear of this loader code
BUFFERSIZE = $8000 ; About max size we can fit between buffer and this loader code
MAINENTRY = $020000
.org $800
LOADSTEP = 3
.macro addProgress amount
jsr nextVBL
lda #amount
jsr advanceLoadingBar
jsr renderLoadingBar
.endmacro
main:
BITS16
NATIVE
; Cache system colors
BITS8
lda BORDERCOLOR
sta BORDERCOLORCACHE
lda TEXTCOLOR
sta TEXTCOLORCACHE
BITS16
; Throw up a loading screen
jsr showLoadingScreen
EMULATION
; Open the main code file
jsr PRODOS
.byte $c8
.addr fileOpenCode
bne ioError
NATIVE
addProgress LOADSTEP
EMULATION
; Load first half of code into bank 0
jsr PRODOS
.byte $ca
.addr fileRead
bne ioError
NATIVE
addProgress LOADSTEP
; Copy code into bank 2
ldx fileReadLen
lda #2
ldy #0
jsr copyBytes
addProgress LOADSTEP
EMULATION
; Load rest of code into bank 0 (needed if code size exceeds BUFFERSIZE)
jsr PRODOS
.byte $ca
.addr fileRead
bne ioError
NATIVE
addProgress LOADSTEP
EMULATION
; Close the file
jsr PRODOS
.byte $cc
.addr fileClose
bra mainContinue
ioError:
brk
mainContinue:
NATIVE
addProgress LOADSTEP
; Copy rest of code into bank 2 (needed if code size exceeds BUFFERSIZE)
ldx fileReadLen
lda #2
ldy #BUFFERSIZE
jsr copyBytes
addProgress LOADSTEP
EMULATION
; Open the sprite bank file
jsr PRODOS
.byte $c8
.addr fileOpenSprites
bne ioError
NATIVE
addProgress LOADSTEP
EMULATION
; Load the compiled sprites into bank 0
jsr PRODOS
.byte $ca
.addr fileRead
bne ioError
NATIVE
addProgress LOADSTEP
EMULATION
; Close the file
jsr PRODOS
.byte $cc
.addr fileClose
NATIVE
addProgress LOADSTEP
; Copy sprites into bank 3
ldx fileReadLen
lda #3
ldy #0
jsr copyBytes
addProgress LOADSTEP
EMULATION
; Open the sound file
jsr PRODOS
.byte $c8
.addr fileOpenSound
bne ioErrorJmp2
NATIVE
addProgress LOADSTEP
EMULATION
; Load the sound data into bank 0
jsr PRODOS
.byte $ca
.addr fileRead
bne ioErrorJmp2
NATIVE
addProgress LOADSTEP
; Copy sound data into bank 4
ldx fileReadLen
txa
sta soundBankSize ; Note size of sound bank for later copying to Ensoniq RAM
lda #4
ldy #0
jsr copyBytes
addProgress LOADSTEP
EMULATION
; Load rest of sound data into bank 4 (needed if sound size exceeds BUFFERSIZE)
jsr PRODOS
.byte $ca
.addr fileRead
bne ioErrorJmp2
NATIVE
addProgress LOADSTEP
EMULATION
; Close the file
jsr PRODOS
.byte $cc
.addr fileClose
NATIVE
bra mainContinue2
ioErrorJmp2:
jmp ioError
mainContinue2:
addProgress LOADSTEP
; Copy rest of sound data into bank 4 (needed if sound size exceeds BUFFERSIZE)
ldx fileReadLen
txa
clc
adc soundBankSize ; Accumulate size of sound bank for later copying to Ensoniq RAM
sta soundBankSize
lda #4
ldy #BUFFERSIZE
jsr copyBytes
addProgress LOADSTEP
EMULATION
; Open the font file
jsr PRODOS
.byte $c8
.addr fileOpenFonts
bne ioErrorJmp
NATIVE
addProgress LOADSTEP
EMULATION
; Load the font data into bank 0
jsr PRODOS
.byte $ca
.addr fileRead
bne ioErrorJmp
NATIVE
addProgress LOADSTEP
; Copy font data into bank 5
ldx fileReadLen
lda #5
ldy #0
jsr copyBytes
addProgress LOADSTEP
EMULATION
; Load rest of font data into bank 0 (needed if font size exceeds BUFFERSIZE)
jsr PRODOS
.byte $ca
.addr fileRead
bne ioErrorJmp
; Close the file
jsr PRODOS
.byte $cc
.addr fileClose
NATIVE
; Copy rest of font data into bank 5 (needed if font size exceeds BUFFERSIZE)
ldx fileReadLen
lda #5
ldy #BUFFERSIZE
jsr copyBytes
bra mainContinue3
ioErrorJmp:
jmp ioError
mainContinue3:
EMULATION
; Open the title screen file
jsr PRODOS
.byte $c8
.addr fileOpenTitle
bne ioErrorJmp
NATIVE
addProgress LOADSTEP
EMULATION
; Load the title screen data into bank 0
jsr PRODOS
.byte $ca
.addr fileRead
bne ioErrorJmp
NATIVE
addProgress LOADSTEP
; Copy title screen data into bank 6
ldx fileReadLen
lda #6
ldy #0
jsr copyBytes
EMULATION
; Close the file
jsr PRODOS
.byte $cc
.addr fileClose
NATIVE
addProgress LOADSTEP
; Set up a long jump into bank 2, and
; a way for game code to get back here to exit
; properly to ProDOS 8
lda #returnToProDOS
sta PRODOSRETURN
lda #skyPalette
sta PARAML2
jsr paletteFade
jml MAINENTRY
returnToProDOS:
SYNCDBR
EMULATION
; Restore system colors
lda BORDERCOLOR
and #$f0
ora BORDERCOLORCACHE
sta BORDERCOLOR
lda TEXTCOLORCACHE
sta TEXTCOLOR
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; copyBytes
; Copy data from read buffer in bank 0 to
; offset any other bank. Must be in native mode.
;
; X = Length of data in bytes
; Y = Origin within bank
; A = Bank number of destination
; loadOffet : offset to start of copy destination
;
copyBytes:
sty copyBytesDest+1
sty copyBytesDest2+1
phx
BITS8
sta copyBytesDest+3
sta copyBytesDest2+3
BITS16
plx
txa
and #1
bne copyBytesOdd
copyBytesEven:
dex
dex
copyBytesLoop:
lda LOADBUFFER,x
copyBytesDest:
sta $010000,x
dex
dex
cpx #$fffe ; X will wrap when we're done
bne copyBytesLoop
rts
copyBytesOdd:
dex
BITS8A
lda LOADBUFFER,x
copyBytesDest2:
sta $010000,x
BITS16
bra copyBytesEven
loadOffet:
.word 0
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
fileOpenCode:
.byte 3
.addr codePath
.addr $9200 ; 1k below BASIC.SYSTEM
.byte 0 ; Result (file handle)
.byte 0 ; Padding
fileRead:
.byte 4
.byte 1 ; File handle (we know it's gonna be 1)
.addr LOADBUFFER
.word BUFFERSIZE
fileReadLen:
.word 0 ; Result (bytes read)
fileClose:
.byte 1
.byte 1 ; File handle (we know it's gonna be 1)
fileOpenSprites:
.byte 3
.addr spritePath
.addr $9200 ; 1k below BASIC.SYSTEM
.byte 0 ; Result (file handle)
.byte 0 ; Padding
fileOpenSound:
.byte 3
.addr soundPath
.addr $9200 ; 1k below BASIC.SYSTEM
.byte 0 ; Result (file handle)
.byte 0 ; Padding
fileOpenFonts:
.byte 3
.addr fontPath
.addr $9200 ; 1k below BASIC.SYSTEM
.byte 0 ; Result (file handle)
.byte 0 ; Padding
fileOpenTitle:
.byte 3
.addr titlePath
.addr $9200 ; 1k below BASIC.SYSTEM
.byte 0 ; Result (file handle)
.byte 0 ; Padding
codePath:
pstring "/GSAPP/CODEBANK"
spritePath:
pstring "/GSAPP/SPRITEBANK"
soundPath:
pstring "/GSAPP/SOUNDBANK"
fontPath:
pstring "/GSAPP/FONTBANK"
titlePath:
pstring "/GSAPP/TITLE"
.include "sharedGraphics.s"
.include "loaderGraphics.s"
.include "loadingBar.s"