Applecorn/mainmem.ldr.s
2022-12-04 15:10:17 -05:00

205 lines
6.1 KiB
ArmAsm

* MAINMEM.LDR.S
* (c) Bobbi 2021 GPLv3
*
* Applecorn loader code. Runs in main memory.
* 01-Oct-2021 Copies MOS code to whole $D000-$FFFF.
* 13-Nov-2021 LOADCODE uses absolute path to Applecorn directory.
* Loads Acorn ROM file (16KB) from disk and writes it
* to aux memory starting at $08000. Copies Applecorn MOS
* to aux memory starting at AUXMOS1 and jumps to it.
* (Note that the MOS code will copy itself to $D000.)
SYSTEM LDX #$FF ; Init stack pointer
TXS
LDA #$00
STA IBAKVER ; Minimum compatible P8 version
LDA #$01
STA IVERSION ; Version of .SYSTEM program
SED ; Check for 65C02
LDA #$99
CLC
ADC #$01
CLD
BPL GOODCPU
JMP UNSUPPORTED
GOODCPU LDA MACHID
AND #$F2 ; Clear bits 0,2,3
CMP #$B2 ; Are we on a //e or //c w/ 80col and 128K or a IIgs?
BEQ SUPPORTED ; Supported machine
JMP UNSUPPORTED ; Unsupported machine
SUPPORTED LDA #$DF ; Protect pages $0,$1,and $3-$7
STA P8BMAP0007
LDA #$F0 ; Protect pages $8-$B
STA P8BMAP080F
LDA #$FF ; Protect HGR1
STA P8BMAP2027
STA P8BMAP282F
STA P8BMAP3037
STA P8BMAP383F
* Set prefix if not already set
SETPRFX LDA #GPFXCMD
STA :OPC7 ; Initialize cmd byte to $C7
:L1 JSR MLI
:OPC7 DB $00
DW GSPFXPL
LDX DRVBUF1 ; was $0300
BNE :CMDPATH
LDA DEVNUM
STA ONLNPL+1 ; Device number
JSR MLI
DB ONLNCMD
DW ONLNPL
LDA DRVBUF2 ; was $0301
AND #$0F
TAX
INX
STX DRVBUF1 ; was $0300
LDA #'/'
STA DRVBUF2 ; was $0301
DEC :OPC7
BNE :L1
:CMDPATH LDA CMDPATH
BEQ :GETPFX ; CMDPATH empty
LDA CMDPATH+1
CMP #'/'
BEQ DISCONN ; CMDPATH already absolute path
:GETPFX JSR MLI
DB GPFXCMD ; Get Prefix
DW GETPFXPARM
* Disconnect /RAM ramdrive to avoid aux corruption
* Stolen from Beagle Bros Extra K
DISCONN LDA MACHID
AND #$30
CMP #$30
BNE :S1
LDA DEVADR32
CMP DEVADR01
BNE :S2
LDA DEVADR32+1
CMP DEVADR01+1
BEQ :S1
:S2 LDY DEVCNT
:L1 LDA DEVLST,Y
AND #$F3
CMP #$B3
BEQ :S3
DEY
BPL :L1
BMI :S1
:S3 LDA DEVLST,Y
STA DRVBUF2+1 ; was $0302
:L2 LDA DEVLST+1,Y
STA DEVLST,Y
BEQ :S4
INY
BNE :L2
:S4 LDA DEVADR32
STA DRVBUF1 ; was $0300
LDA DEVADR32+1
STA DRVBUF2 ; was $0301
LDA DEVADR01
STA DEVADR32
LDA DEVADR01+1
STA DEVADR32+1
DEC DEVCNT
:S1 JSR ROMMENU ; This really needs to happen elsewhere
JSR RESETHW ; Reset any hardware required
LDA #<:FDFILE
STA OPENPL+1
LDA #>:FDFILE
STA OPENPL+2
LDA #>FDRAWADDR ; Address in main
LDX #<FDRAWADDR
CLC ; Load into main
JSR LOADCODE
LDA #<:FNTFILE
STA OPENPL+1
LDA #>:FNTFILE
STA OPENPL+2
LDA #>FONTADDR ; Address in main
LDX #<FONTADDR
CLC ; Load into main
JSR LOADCODE
LDA #<MOSSHIM ; Start address of MOS shim
STA A1L
LDA #>MOSSHIM
STA A1H
LDA #<MOSSHIM+$3000 ; End address of MOS shim
STA A2L
LDA #>MOSSHIM+$3000
STA A2H
LDA #<AUXMOS1 ; To AUXMOS1 in aux memory
STA A4L
LDA #>AUXMOS1
STA A4H
SEC ; Copy MOS from Main->Aux
JSR AUXMOVE
LDA #<RESET ; Set reset vector->RESET
STA RSTV
LDA #>RESET
STA RSTV+1
EOR #$A5 ; Checksum
STA PWRDUP
LDA #<GSBRK ; Set BREAK vector in main mem
STA BREAKV
LDA #>GSBRK
STA BREAKV+1
JSR GFXINIT ; Initialize FDraw graphics
TSX ; Save SP at $0100 in aux
>>> ALTZP
STX $0100
>>> MAINZP
>>> XF2AUX,AUXMOS1
* Filenames for loaded binaries - we're gonna address these later
:FDFILE STR "FDRAW.FAST" ; Filename for FDraw lib
:FNTFILE STR "FONT.DAT" ; Filename for bitmap font
GETPFXPARM HEX 01 ; One parameter
DW CMDPATH ; Get prefix to CMDPATH
UNSUPPORTED JSR HOME
LDX #$00
UNSUPLP LDA UNSUPMSG,X
BEQ UNSUPWAIT
JSR COUT1
INX
BNE UNSUPLP
UNSUPWAIT STA KBDSTRB
UNSUPKEY LDA KEYBOARD
BPL UNSUPKEY
STA KBDSTRB
JSR MLI
DB QUITCMD
DW UNSUPQPARM
UNSUPQPARM DB $04,$00,$00,$00,$00,$00,$00
UNSUPMSG ASC "APPLECORN REQUIRES AN APPLE IIGS, APPLE", 8D
ASC "//C, OR ENHANCED APPLE //E WITH AN", 8D
ASC "80-COLUMN CARD AND AT LEAST 128K", 8D, 8D
ASC "PRESS ANY KEY TO QUIT TO PRODOS", 00
ENDSYSTEM