--- /dev/null
+;
+; Karri Kaksonen, 2011
+;
+; This bootloader creates a signed binary so that the Lynx will accept it.
+;
+ .include "lynx.inc"
+ .include "extzp.inc"
+ .import __BLOCKSIZE__
+ .export __BOOTLDR__: absolute = 1
+
+
+; ------------------------------------------------------------------------
+; Bootloader
+
+ .segment "BOOTLDR"
+;**********************************
+; 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 size (171 bytes)
+;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.
+;**********************************
+ .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
+;**********************************
+ .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
+
+ ; 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
+
--- /dev/null
+;
+; Karri Kaksonen, 2011
+;
+; A default directory with just the main executable.
+;
+ .include "lynx.inc"
+ .import __STARTOFDIRECTORY__
+ .import __RAM_START__
+ .import __CODE_SIZE__,__DATA_SIZE__,__RODATA_SIZE__
+ .import __STARTUP_SIZE__,__INIT_SIZE__
+ .import __BLOCKSIZE__
+ .export __DEFDIR__: absolute = 1
+
+
+; ------------------------------------------------------------------------
+; Lynx directory
+ .segment "DIRECTORY"
+
+__DIRECTORY_START__:
+off0=__STARTOFDIRECTORY__+(__DIRECTORY_END__-__DIRECTORY_START__)
+blocka=off0/__BLOCKSIZE__
+; 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 $88
+ .word __RAM_START__
+ .word len0
+__DIRECTORY_END__:
+
;
; Karri Kaksonen, 2011
;
-; This header is required for cart builds.
+; This header contains data for emulators like Handy and Mednafen
;
- .include "lynx.inc"
- .include "extzp.inc"
- .import __RAM_START__
- .import __CODE_SIZE__,__DATA_SIZE__,__RODATA_SIZE__
- .import __STARTUP_SIZE__,__INIT_SIZE__
.import __BLOCKSIZE__
.export __EXEHDR__: absolute = 1
; rotation 2=right
.byte 0,0,0,0,0 ; spare
-;**********************************
-; 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
-
- ; 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
-
-__DIRECTORY_START__:
-; Entry 0 - title sprite (mandatory)
-off0=__LOADER_SIZE__+__LOADER2_SIZE__+(__DIRECTORY_END__-__DIRECTORY_START__)
-blocka=off0/__BLOCKSIZE__
-; 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 $88
- .word __RAM_START__
- .word len0
-__DIRECTORY_END__:
-
;----------------------------------------------------------------------------
; Global variables
;
-; The ring buffers will be at the fixed place
-; Tx buffer $200 - $2ff. Rx buffer $300 - $3ff.
-; This memory area can usually not be used for anything as the encryption
-; stuff needs it. But for this purpose it fits perfectly.
.bss
-TxBuffer = $0200
-RxBuffer = $0300
+TxBuffer: .res 256
+RxBuffer: .res 256
RxPtrIn: .res 1
RxPtrOut: .res 1
TxPtrIn: .res 1
__STARTOFDIRECTORY__: type = weak, value = $00DF; # start just after loader
__BLOCKSIZE__: type = weak, value = 1024; # cart block size
__EXEHDR__: type = import;
+ __BOOTLDR__: type = import;
+ __DEFDIR__: type = import;
}
MEMORY {
ZP: file = "", define = yes, start = $0000, size = $0100;
- HEADER: file = %O, start = $0000, size = $021e;
- RAM: file = %O, define = yes, start = $0400, size = $9C58 - __STACKSIZE__;
+ HEADER: file = %O, start = $0000, size = $0040;
+ BOOT: file = %O, start = $0200, size = __STARTOFDIRECTORY__;
+ DIR: file = %O, start = $0000, size = 8;
+ RAM: file = %O, define = yes, start = $0200, size = $9E58 - __STACKSIZE__;
}
SEGMENTS {
EXEHDR: load = HEADER, type = ro;
+ BOOTLDR: load = BOOT, type = ro;
+ DIRECTORY:load = DIR, type = ro;
STARTUP: load = RAM, type = ro, define = yes;
LOWCODE: load = RAM, type = ro, optional = yes;
INIT: load = RAM, type = ro, define = yes, optional = yes;
__STARTOFDIRECTORY__: type = weak, value = $00DF; # start just after loader
__BLOCKSIZE__: type = weak, value = 1024; # cart block size
__EXEHDR__: type = import;
+ __BOOTLDR__: type = import;
+ __DEFDIR__: type = import;
}
MEMORY {
ZP: file = "", define = yes, start = $0000, size = $0100;
- HEADER: file = %O, start = $0000, size = $021e;
- RAM: file = %O, define = yes, start = $0400, size = $BC38 - __STACKSIZE__;
+ HEADER: file = %O, start = $0000, size = $0040;
+ BOOT: file = %O, start = $0200, size = __STARTOFDIRECTORY__;
+ DIR: file = %O, start = $0000, size = 8;
+ RAM: file = %O, define = yes, start = $0200, size = $BE38 - __STACKSIZE__;
}
SEGMENTS {
EXEHDR: load = HEADER, type = ro;
+ BOOTLDR: load = BOOT, type = ro;
+ DIRECTORY:load = DIR, type = ro;
STARTUP: load = RAM, type = ro, define = yes;
LOWCODE: load = RAM, type = ro, optional = yes;
INIT: load = RAM, type = ro, define = yes, optional = yes;
projects / cc65 / commitdiff