mirror of
https://github.com/cc65/cc65.git
synced 2024-12-23 19:29:37 +00:00
a3d8829be9
This change includes some cleanups, removal of mainargs.s (game console programs never have arguments), and a workaround for a problem I'm seeing. The problem is that sometimes (in fact, more often than not) the clrscr() call in testcode/lib/joy-test.c writes some garbage chars on the screen (most often a "P"). Could be my hardware (I haven't seen it on MAME), but to me the root cause is still unknown.
110 lines
3.3 KiB
ArmAsm
110 lines
3.3 KiB
ArmAsm
;
|
|
; Startup code for cc65 (CreatiVision version)
|
|
;
|
|
|
|
.export _exit
|
|
.export __STARTUP__ : absolute = 1 ; Mark as startup
|
|
.export irq2
|
|
.import zerobss, copydata
|
|
.import initlib, donelib, callmain
|
|
.import __VECTORS_LOAD__, __VECTORS_RUN__, __VECTORS_SIZE__
|
|
.import __ZP_LAST__, __STACKSIZE__, __RAM_START__
|
|
|
|
.include "creativision.inc"
|
|
.include "zeropage.inc"
|
|
|
|
; ------------------------------------------------------------------------
|
|
|
|
entry:
|
|
; Init the CPU
|
|
sei
|
|
cld
|
|
|
|
; Copy the IRQ vectors
|
|
ldx #<__VECTORS_SIZE__ - 1
|
|
: lda __VECTORS_LOAD__,x
|
|
sta __VECTORS_RUN__,x
|
|
dex
|
|
bpl :-
|
|
|
|
; Setup the CPU stack ptr
|
|
ldx #<__RAM_START__ - 1
|
|
txs
|
|
|
|
; Clear the BSS data
|
|
jsr zerobss
|
|
|
|
; Copy data from ROM to RAM
|
|
jsr copydata
|
|
|
|
; Setup the argument stack ptr
|
|
lda #<(__ZP_LAST__ + __STACKSIZE__)
|
|
ldx #>(__ZP_LAST__ + __STACKSIZE__)
|
|
sta sp
|
|
stx sp+1
|
|
|
|
; Call module constructors
|
|
jsr initlib
|
|
|
|
; enable vertical blank interrupts in the display controller
|
|
lda #$E0 ; 16K RAM, Active Display, Mode 1, VBI enabled
|
|
ldx #$01 ; Register 1
|
|
jsr BIOS_WRITE_VDP_REG
|
|
|
|
; Start interrupts
|
|
cli
|
|
|
|
; Call main()
|
|
jsr callmain
|
|
|
|
; Call module destructors. This is also the _exit entry.
|
|
_exit: jsr donelib
|
|
|
|
; A Creativision program isn't supposed to exit.
|
|
loop: jmp loop
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Define the IRQ vectors.
|
|
|
|
.segment "VECTORS"
|
|
|
|
irq1: jmp BIOS_IRQ1_ADDR
|
|
irq2: jmp BIOS_IRQ2_ADDR
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Define CART setup values for BIOS.
|
|
|
|
.segment "SETUP"
|
|
|
|
; BIOS Jump Start
|
|
; This is where the entry point of the program needs to be
|
|
.addr entry
|
|
.addr irq2
|
|
|
|
.res 4
|
|
|
|
; VDP Setup
|
|
; This sets to Graphics Mode 1
|
|
.byte $00 ; Register 0
|
|
.byte $C0 ; Register 1 16K RAM, Active Display, Mode 1, VBI disabled
|
|
.byte $04 ; Register 2 Name Table at $1000 - $12FF
|
|
.byte $60 ; Register 3 Colour Table at $1800 - $181F
|
|
.byte $00 ; Register 4 Pattern Table at $0000 - $07FF
|
|
.byte $10 ; Register 5 Sprite Attribute at $0800 - $087F
|
|
.byte $01 ; Register 6 Sprite Pattern
|
|
.byte $F1 ; Register 7 Text colour Foreground / background
|
|
|
|
.res 4
|
|
|
|
; BIOS Vector after NMI or RESET
|
|
; Keeping with retail cartridges, we jump back to BIOS ROM and have it
|
|
; setup zeropage etc, and show the Creativision logo and copyright.
|
|
.addr BIOS_NMI_RESET_ADDR
|
|
|
|
; BIOS Short Interrupt Handler
|
|
; Vectored from BIOS ROM:FE2C. This should contain a pointer to the user's
|
|
; BIOS interrupt handler.
|
|
.addr irq1
|
|
|
|
; ------------------------------------------------------------------------
|