;
; This header is required for cart builds.
;
+ .include "lynx.inc"
+ .include "extzp.inc"
.import __RAM_START__
.import __CODE_SIZE__,__DATA_SIZE__,__RODATA_SIZE__
.import __STARTUP_SIZE__,__INIT_SIZE__
; rotation 2=right
.byte 0,0,0,0,0 ; spare
-.if (.match (__BLOCKSIZE__, 2048))
-__LOADER_SIZE__=0
-.elseif (.match (__BLOCKSIZE__, 512))
-__LOADER_SIZE__=0
-.else
-__LOADER_SIZE__=410
+;**********************************
+; Here is the bootloader in plaintext
+; The idea is to make the smalles possible encrypted loader as decryption
+; is very slow. The minimum size is 49 bytes plus a zero byte.
+;**********************************
+; EXE = $f000
+;
+; .org $0200
+;
+; ; 1. force Mikey to be in memory
+; stz MAPCTL
+;
+; ; 3. set ComLynx to open collector
+; lda #4 ; a = 00000100
+; sta SERCTL ; set the ComLynx to open collector
+;
+; ; 4. make sure the ROM is powered on
+; lda #8 ; a = 00001000
+; sta IODAT ; set the ROM power to on
+;
+; ; 5. read in secondary exe + 8 bytes from the cart and store it in $f000
+; ldx #0 ; x = 0
+; ldy #$AB ; y = secondary loader
+;rloop1: lda RCART0 ; read a byte from the cart
+; sta EXE,X ; EXE[X] = a
+; inx ; x++
+; dey ; y--
+; bne rloop1 ; loops until y wraps
+;
+; ; 6. jump to secondary loader
+; jmp EXE ; run the secondary loader
+;
+; .reloc
+;**********************************
+; After compilation, encryption and obfuscation it turns into this.
+;**********************************
+__LOADER_SIZE__=52
+ .byte $ff, $dc, $e3, $bd, $bc, $7f, $f8, $94
+ .byte $b7, $dd, $68, $bb, $da, $5b, $50, $5c
+ .byte $ea, $9f, $2b, $df, $96, $80, $3f, $7e
+ .byte $ef, $15, $81, $ae, $ad, $e4, $6e, $b3
+ .byte $46, $d7, $72, $58, $f7, $76, $8a, $4a
+ .byte $c7, $99, $bd, $ff, $02, $3e, $5b, $3f
+ .byte $0c, $49, $1b, $22
+
+;**********************************
+; Now we have the secondary loader
+;**********************************
+__LOADER2_SIZE__=171
+ .org $f000
+ ; 1. Read in the 1st File-entry (main exe) in FileEntry
+ ldx #$00
+ ldy #8
+rloop: lda RCART0 ; read a byte from the cart
+ sta _FileEntry,X ; EXE[X] = a
+ inx
+ dey
+ bne rloop
+
+ ; 2. Set the block hardware to the main exe start
+ lda _FileStartBlock
+ sta _FileCurrBlock
+ jsr seclynxblock
+
+ ; 3. Skip over the block offset
+ lda _FileBlockOffset
+ ldx _FileBlockOffset+1
+ phx ; The BLL kit uses negative offsets
+ plx ; while the basic Lynx uses positive
+ bmi @1 ; Make all offsets negative
+ eor #$FF
+ pha
+ txa
+ eor #$FF
+ bra @2
+@1: pha
+ txa
+@2: tay
+ plx
+ jsr seclynxskip0
+
+ ; 4. Read in the main exe to RAM
+ lda _FileDestAddr
+ ldx _FileDestAddr+1
+ sta _FileDestPtr
+ stx _FileDestPtr+1
+ lda _FileFileLen
+ ldx _FileFileLen+1
+ phx ; The BLL kit uses negative counts
+ plx ; while the basic Lynx uses positive
+ bmi @3 ; make all counts negative
+ eor #$FF
+ pha
+ txa
+ eor #$FF
+ bra @4
+@3: pha
+ txa
+@4: tay
+ plx
+ jsr seclynxread0
- ; The cart starts with an encrypted loader for 1024 bytes/block
- ; images. The size of the loader is 410 bytes followed by two
- ; mandatory directory entries.
- .byte $FD,$C1,$0D,$8E,$E9,$EE,$09,$13,$E5,$96
- .byte $0C,$34,$64,$DA,$D4,$BB,$99,$EC,$CE,$4F
- .byte $AA,$8C,$ED,$65,$F0,$32,$70,$A3,$84,$C4
- .byte $FC,$A2,$6D,$3A,$F8,$77,$4B,$AC,$9B,$54
- .byte $7D,$82,$6F,$F8,$A5,$06,$4D,$7B,$77,$55
- .byte $E4,$31,$C4,$2C,$2F,$2F,$B6,$4D,$15,$A9
- .byte $C7,$99,$5D,$6E,$B3,$97,$92,$44,$7B,$2B
- .byte $85,$18,$E6,$F1,$96,$F4,$C4,$DE,$A4,$CF
- .byte $79,$E2,$C1,$1A,$E0,$0C,$93,$C5,$26,$BD
- .byte $A3,$16,$8A,$C3,$59,$A0,$39,$38,$A0,$3B
- .byte $EF,$BB,$1D,$5C,$0D,$1D,$CC,$48,$1D,$DD
- .byte $98,$9A,$7A,$F7,$96,$F9,$61,$03,$50,$DA
- .byte $47,$69,$94,$C3,$80,$DA,$A9,$99,$A1,$21
- .byte $2B,$2E,$7D,$F5,$E4,$F7,$B3,$5C,$A8,$14
- .byte $FA,$E9,$06,$AC,$1E,$9F,$B5,$31,$BE,$42
- .byte $14,$08,$0E,$05,$FB,$25,$BB,$5C,$5C,$66
- .byte $76,$8E,$36,$E8,$EB,$39,$F2,$26,$BD,$17
- .byte $29,$F4,$B8,$1D,$7E,$EE,$47,$61,$BB,$9E
- .byte $F5,$72,$C9,$BC,$26,$37,$D5,$78,$8F,$D0
- .byte $CE,$95,$21,$EB,$4A,$07,$8D,$3A,$3A,$01
- .byte $82,$CF,$01,$C5,$1E,$1D,$A8,$41,$4F,$BD
- .byte $C1,$76,$22,$A3,$88,$D9,$57,$C9,$51,$3A
- .byte $26,$BE,$4A,$1A,$7F,$42,$61,$CF,$FC,$FC
- .byte $5B,$06,$94,$D2,$2C,$78,$45,$BA,$93,$C4
- .byte $7D,$7C,$81,$73,$07,$4F,$E2,$6C,$E9,$81
- .byte $1A,$DE,$77,$74,$87,$DE,$26,$9E,$7A,$A8
- .byte $19,$A7,$34,$32,$70,$ED,$59,$A8,$4A,$D8
- .byte $FE,$CB,$DD,$02,$2F,$CE,$92,$E9,$13,$A6
- .byte $FF,$B4,$4B,$18,$9D,$63,$48,$E0,$3B,$3B
- .byte $0D,$2B,$FC,$04,$A4,$E3,$5E,$4C,$3C,$94
- .byte $70,$C4,$F0,$64,$15,$48,$68,$17,$DE,$14
- .byte $72,$F0,$59,$33,$4C,$49,$47,$8D,$B6,$F4
- .byte $82,$4E,$B7,$4E,$01,$C9,$C2,$82,$0B,$7A
- .byte $AC,$67,$9B,$0F,$04,$E1,$B6,$78,$34,$C8
- .byte $4F,$2A,$11,$ED,$D0,$1C,$6D,$CD,$3D,$47
- .byte $09,$8B,$E5,$38,$19,$7A,$31,$6E,$30,$71
- .byte $1C,$90,$34,$E5,$44,$CC,$00,$C7,$41,$D0
- .byte $27,$8A,$06,$29,$5C,$2B,$E4,$26,$63,$09
- .byte $52,$D3,$97,$33,$D7,$59,$1C,$36,$2F,$C9
- .byte $A9,$A2,$B5,$BB,$A9,$1D,$E6,$36,$7E,$56
- .byte $05,$A4,$9C,$E0,$45,$59,$21,$E1,$E6,$21
-.endif
+ ; 5. Jump to start of the main exe code
+ jmp (_FileDestAddr)
+
+;**********************************
+; Skip bytes on bank 0
+; X:Y count (EOR $FFFF)
+;**********************************
+seclynxskip0:
+ inx
+ bne @0
+ iny
+ beq exit
+@0: jsr secreadbyte0
+ bra seclynxskip0
+
+;**********************************
+; Read bytes from bank 0
+; X:Y count (EOR $ffff)
+;**********************************
+seclynxread0:
+ inx
+ bne @1
+ iny
+ beq exit
+@1: jsr secreadbyte0
+ sta (_FileDestPtr)
+ inc _FileDestPtr
+ bne seclynxread0
+ inc _FileDestPtr+1
+ bra seclynxread0
+
+;**********************************
+; Read one byte from cartridge
+;**********************************
+secreadbyte0:
+ lda RCART0
+ inc _FileBlockByte
+ bne exit
+ inc _FileBlockByte+1
+ bne exit
+
+;**********************************
+; Select a block
+;**********************************
+seclynxblock:
+ pha
+ phx
+ phy
+ lda __iodat
+ and #$fc
+ tay
+ ora #2
+ tax
+ lda _FileCurrBlock
+ inc _FileCurrBlock
+ sec
+ bra @2
+@0: bcc @1
+ stx IODAT
+ clc
+@1: inx
+ stx SYSCTL1
+ dex
+@2: stx SYSCTL1
+ rol
+ sty IODAT
+ bne @0
+ lda __iodat
+ sta IODAT
+ stz _FileBlockByte
+ lda #<($100-(>__BLOCKSIZE__))
+ sta _FileBlockByte+1
+ ply
+ plx
+ pla
+
+exit: rts
+ .reloc
- ; The directory structure required by the 410 byte bootloader
__DIRECTORY_START__:
; Entry 0 - title sprite (mandatory)
-off0=__LOADER_SIZE__+(__DIRECTORY_END__-__DIRECTORY_START__)
+off0=__LOADER_SIZE__+__LOADER2_SIZE__+(__DIRECTORY_END__-__DIRECTORY_START__)
blocka=off0/__BLOCKSIZE__
-len0=(__TITLE_END__-__TITLE_START__)
- .byte <blocka
+; Entry 0 - first executable
+block0=off0/__BLOCKSIZE__
+len0=__STARTUP_SIZE__+__INIT_SIZE__+__CODE_SIZE__+__DATA_SIZE__+__RODATA_SIZE__
+ .byte <block0
.word off0 & (__BLOCKSIZE__ - 1)
- .byte $00
- .word __TITLE_START__
- .word len0
-
-; Entry 1 - first executable (mandatory)
-off1=off0+len0
-block1=off1/__BLOCKSIZE__
-len1=__STARTUP_SIZE__+__INIT_SIZE__+__CODE_SIZE__+__DATA_SIZE__+__RODATA_SIZE__
- .byte <block1
- .word off1 & (__BLOCKSIZE__ - 1)
.byte $88
.word __RAM_START__
- .word len1
+ .word len0
__DIRECTORY_END__:
- .org $2400
-__TITLE_START__:
- ; The palette for the title sprite. Complete black.
- .byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
- .byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
- ; The title sprite
-cls_sprite:
- .byte %00000001 ; A pixel sprite
- .byte %00010000
- .byte %00100000
- .addr 0,pixel_bitmap
- .word 0
- .word 0
- .word $a000 ; 160
- .word $6600 ; 102
- .byte $00
-pixel_bitmap:
- .byte 3,%10000100,%00000000, $0 ; A pixel bitmap
-__TITLE_END__:
- .reloc
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