;
; ***
;
-; Startup code for cc65 (Lynx version). Based on Atari 8-bit startup
+; Startup code for cc65 (Lynx version). Based on the Atari 8-bit startup
; code structure. The C stack is located at the end of the RAM memory
-; segment and grows downward. Bastian Schick's executable header is put
+; segment, and grows downward. Bastian Schick's executable header is put
; on the front of the fully linked binary (see EXEHDR segment.)
;
- .include "lynx.inc"
- .export _exit
+ .export _exit
.export __STARTUP__ : absolute = 1 ; Mark as startup
- .import callirq, initlib, donelib
- .import zerobss
- .import callmain
- .import _main
- .import __BSS_LOAD__
- .import __INTERRUPTOR_COUNT__
- .import __RAM_START__, __RAM_SIZE__
+ .import initlib, donelib
+ .import zerobss
+ .import callmain
+ .import _main
+ .import __MAIN_START__, __MAIN_SIZE__, __STACKSIZE__
- .include "zeropage.inc"
+ .include "zeropage.inc"
.include "extzp.inc"
-
-
-; ------------------------------------------------------------------------
-; EXE header (BLL header)
-
- .segment "EXEHDR"
- .word $0880
- .dbyt __RAM_START__
- .dbyt __BSS_LOAD__ - __RAM_START__ + 10
- .byte $42,$53
- .byte $39,$33
-
+ .include "lynx.inc"
; ------------------------------------------------------------------------
; Mikey and Suzy init data, reg offsets and data
- .rodata
+ .rodata
SuzyInitReg: .byte $28,$2a,$04,$06,$92,$83,$90
SuzyInitData: .byte $7f,$7f,$00,$00,$24,$f3,$01
MikeyInitReg: .byte $00,$01,$08,$09,$20,$28,$30,$38,$44,$50,$8a,$8b,$8c,$92,$93
MikeyInitData: .byte $9e,$18,$68,$1f,$00,$00,$00,$00,$00,$ff,$1a,$1b,$04,$0d,$29
-
; ------------------------------------------------------------------------
; Actual code
- .segment "STARTUP"
+ .segment "STARTUP"
-; set up system
+; Set up the system.
- sei
- cld
- ldx #$FF
- txs
+ sei
+ ldx #$FF
+ txs
-; init bank switching
+; Init the bank switching.
- lda #$C
- sta MAPCTL ; $FFF9
+ lda #$C
+ sta MAPCTL ; $FFF9
-; disable all timer interrupts
+; Disable all timer interrupts.
- lda #$80
- trb TIM0CTLA
- trb TIM1CTLA
- trb TIM2CTLA
- trb TIM3CTLA
- trb TIM5CTLA
- trb TIM6CTLA
- trb TIM7CTLA
+ lda #$80
+ trb TIM0CTLA
+ trb TIM1CTLA
+ trb TIM2CTLA
+ trb TIM3CTLA
+ trb TIM5CTLA
+ trb TIM6CTLA
+ trb TIM7CTLA
-; disable TX/RX IRQ, set to 8E1
+; Disable the TX/RX IRQ; set to 8E1.
- lda #%11101
- sta SERCTL
+ lda #%11101
+ sta SERCTL
-; clear all pending interrupts
+; Clear all pending interrupts.
- lda INTSET
- sta INTRST
+ lda INTSET
+ sta INTRST
-; setup the stack
+; Set up the stack.
- lda #<(__RAM_START__ + __RAM_SIZE__)
- sta sp
- lda #>(__RAM_START__ + __RAM_SIZE__)
- sta sp+1
+ lda #<(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)
+ ldx #>(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)
+ sta sp
+ stx sp+1
-; Init Mickey
+; Init Mickey.
- ldx #.sizeof(MikeyInitReg)-1
+ ldx #.sizeof(MikeyInitReg)-1
mloop: ldy MikeyInitReg,x
- lda MikeyInitData,x
- sta $fd00,y
- dex
- bpl mloop
+ lda MikeyInitData,x
+ sta $fd00,y
+ dex
+ bpl mloop
-; these are RAM-shadows of read only regs
+; These are RAM-shadows of read-only regs.
- ldx #$1b
- stx __iodat
- dex ; $1A
- stx __iodir
- ldx #$d
- stx __viddma
+ ldx #$1b
+ stx __iodat
+ dex ; $1A
+ stx __iodir
+ ldx #$d
+ stx __viddma
-; Init Suzy
+; Init Suzy.
- ldx #.sizeof(SuzyInitReg)-1
+ ldx #.sizeof(SuzyInitReg)-1
sloop: ldy SuzyInitReg,x
- lda SuzyInitData,x
- sta $fc00,y
- dex
- bpl sloop
+ lda SuzyInitData,x
+ sta $fc00,y
+ dex
+ bpl sloop
- lda #$24
- sta __sprsys
+ lda #$24
+ sta __sprsys
+ cli
-; Clear the BSS data
+; Clear the BSS data.
- jsr zerobss
+ jsr zerobss
-; If we have IRQ functions, set the IRQ vector
-; as Lynx is a console there is not much point in releasing the IRQ
+; Call the module constructors.
- lda #<__INTERRUPTOR_COUNT__
- beq NoIRQ1
- lda #<IRQStub
- ldx #>IRQStub
- sei
- sta INTVECTL
- stx INTVECTH
- cli
+ jsr initlib
-; Call module constructors
-
-NoIRQ1: jsr initlib
-
-; Push arguments and call main
+; Push the command-line arguments; and, call main().
jsr callmain
-; Call module destructors. This is also the _exit entry.
+; Call the module destructors. This is also the exit() entry.
_exit: jsr donelib ; Run module destructors
; Endless loop
noret: bra noret
-
-
- .segment "CODE"
-IRQStub:
- phy
- phx
- pha
- cld
- jsr callirq
- lda INTSET
- sta INTRST
- pla
- plx
- ply
- rti
-
projects / cc65 / blobdiff