Apple2-IO-RPi/Apple2/MenuFirmware.asm
2024-04-18 14:23:22 -04:00

219 lines
3.8 KiB
NASM

; Copyright Terence J. Boldt (c)2020-2024
; Use of this source code is governed by an MIT
; license that can be found in the LICENSE file.
; This file contains the source for the firmware
; that displays the copyright message on boot
; and checks for the RPi status to be ready before
; attempting to boot
;ProDOS Zero Page
Command = $42 ;ProDOS Command
Unit = $43 ;ProDOS unit (SDDD0000)
BufferLo = $44
BufferHi = $45
BlockLo = $46
BlockHi = $47
; ProDOS Error Codes
IOError = $27
NoDevice = $28
WriteProtect = $2B
InputByte = $c08e+SLOT*$10
OutputByte = $c08d+SLOT*$10
InputFlags = $c08b+SLOT*$10
OutputFlags = $c087+SLOT*$10
ResetCommand = $00
ReadBlockCommand = $01
WriteBlockCommand = $02
GetTimeCommand = $03
ChangeDriveCommand = $04
ExecCommand = $05
LoadFileCommand = $06
SaveFileCommand = $07
MenuCommand = $08
Wait = $fca8
PrintChar = $fded
Home = $fc58
ReadChar = $fd0c
BasCalc = $fbc1
htab = $24
vtab = $25
BasL = $28
htab80 = $057b
.org SLOT*$100 + $C000
;ID bytes for booting and drive detection
cpx #$20 ;ID bytes for ProDOS
cpx #$00 ;
cpx #$03 ;
cpx #$3C ;ID byte for Autostart ROM
lda #$3f ;set all flags high and page 3 of EPROM for menu
jmp PageJump
;The following bytes must exist in this location for Pascal communications
;as they are standard pointers for entry points
.byte CommInit&$00FF ;low byte of rts for init of Pascal comms
.byte $43 ; low byte of read for Pascal comms
.byte $49 ; low byte of write for Pascal comms
.byte $4F ; low byte of rts for status of Pascal comms
CommInit:
lda #$0f ; set all flags high and page 0 for comm driver
sta OutputFlags
ldx #$00 ; set error code to 0 for success
rts
PageJump:
sta OutputFlags
jmp Start ;this jump is only called if coming in from PageJump with A=$0f
;entry points for ProDOS
DriverEntry:
lda #$0f ;set all flags high and page 0 of EPROM
sta OutputFlags
;since the firmware page changes to 0, this falls through to the driver
Start:
lda #$f0 ;restore COUT after PR# called
sta $36
lda #$fd
sta $37
;jsr Home ;clear screen and show menu options
lda #$02
sta vtab
jsr BasCalc
ldy #$00
sty htab
PrintString:
lda Text,y
beq WaitForRPi
ora #$80
jsr PrintChar
iny
bne PrintString
.if HW_TYPE = 0
WaitForRPi:
bit InputFlags
bmi Reset
lda #$ff
jsr Wait
lda #'.'+$80
jsr PrintChar
jmp WaitForRPi
Reset:
lda #'_'|$80
jsr PrintChar
lda #ResetCommand
jsr SendByte
lda #$88
jsr PrintChar
lda #'.'|$80
jsr PrintChar
jsr GetByte
beq Ok
jmp Reset
.else
WaitForRPi:
@1:
bit InputFlags
bmi @2
lda InputByte
jmp @1
@2:
bit InputFlags
bpl @4
bvs @3
lda #ResetCommand
sta OutputByte
@3:
lda #$ff
jsr Wait
lda #'.'+$80
jsr PrintChar
jmp @2
@4:
lda #$ff
jsr Wait
@5:
bit InputFlags
bmi Ok
lda InputByte
jmp @5
.endif
Ok:
lda #$8D
jsr PrintChar
lda #'O'|$80
jsr PrintChar
lda #'K'|$80
jsr PrintChar
Boot:
lda #$0f
jmp PageJump
SendByte:
bit InputFlags
bvs SendByte
sta OutputByte
.if HW_TYPE = 0
lda #$3e ; set bit 0 low to indicate write started
sta OutputFlags
finishWrite:
bit InputFlags
bvc finishWrite
lda #$3f
sta OutputFlags
.endif
rts
GetByte:
.if HW_TYPE = 0
ldx #$3d ;set read flag low
stx OutputFlags
.endif
waitRead:
bit InputFlags
bmi waitRead
lda InputByte
.if HW_TYPE = 0
ldx #$3f ;set all flags high
stx OutputFlags
finishRead:
bit InputFlags
bpl finishRead
.endif
rts
Text:
.byte "Apple2-IO-RPi",$8d
.byte "(c)2020-2024 Terence J. Boldt",$8d
.byte $8d
.if HW_TYPE = 0
.byte "Waiting for RPi FW:0011"
.else
.byte "Waiting for RPi FW:8011"
.endif
end:
.byte $00
.repeat 251-<end
.byte 0
.endrepeat
.byte 0,0 ;0000 blocks = check status
.byte 7 ;bit set(0=status 1=read 2=write) unset(3=format, 4/5=number of volumes, 6=interruptable, 7=removable)
.byte DriverEntry&$00FF ;low byte of entry