mirror of
https://github.com/cc65/cc65.git
synced 2024-11-19 06:31:31 +00:00
133 lines
2.5 KiB
ArmAsm
133 lines
2.5 KiB
ArmAsm
|
;
|
||
|
|
; Startup code for cc65 (C64 version)
|
||
|
|
;
|
||
|
|
; This must be the *first* file on the linker command line
|
||
|
|
;
|
||
|
|
|
||
|
|
.export _exit
|
||
|
|
.import __hinit, initconio, zerobss, push0, doatexit
|
||
|
|
.import _main
|
||
|
|
|
||
|
|
.include "c64.inc"
|
||
|
|
.include "../cbm/cbm.inc"
|
||
|
|
|
||
|
|
; ------------------------------------------------------------------------
|
||
|
|
; Define and export the ZP variables for the C64 runtime
|
||
|
|
|
||
|
|
.exportzp sp, sreg, regsave
|
||
|
|
.exportzp ptr1, ptr2, ptr3, ptr4
|
||
|
|
.exportzp tmp1, tmp2, tmp3, tmp4
|
||
|
|
.exportzp regbank, zpspace
|
||
|
|
|
||
|
|
sp = $02 ; stack pointer
|
||
|
|
sreg = $04 ; secondary register/high 16 bit for longs
|
||
|
|
regsave = $06 ; slot to save/restore (E)AX into
|
||
|
|
ptr1 = $0A ;
|
||
|
|
ptr2 = $0C
|
||
|
|
ptr3 = $0E
|
||
|
|
ptr4 = $10
|
||
|
|
tmp1 = $12
|
||
|
|
tmp2 = $13
|
||
|
|
tmp3 = $14
|
||
|
|
tmp4 = $15
|
||
|
|
regbank = $16 ; 6 byte register bank
|
||
|
|
zpspace = $1A ; Zero page space allocated
|
||
|
|
|
||
|
|
; ------------------------------------------------------------------------
|
||
|
|
; BASIC header with a SYS call
|
||
|
|
|
||
|
|
.org $7FF
|
||
|
|
.word Head ; Load address
|
||
|
|
Head: .word @Next
|
||
|
|
.word 1000 ; Line number
|
||
|
|
.byte $9E,"2061" ; SYS 2061
|
||
|
|
.byte $00 ; End of BASIC line
|
||
|
|
@Next: .word 0 ; BASIC end marker
|
||
|
|
.reloc
|
||
|
|
|
||
|
|
; ------------------------------------------------------------------------
|
||
|
|
; Actual code
|
||
|
|
|
||
|
|
ldy #zpspace-1
|
||
|
|
L1: lda sp,y
|
||
|
|
sta zpsave,y ; Save the zero page locations we need
|
||
|
|
dey
|
||
|
|
bpl L1
|
||
|
|
|
||
|
|
; Close open files
|
||
|
|
|
||
|
|
jsr CLRCH
|
||
|
|
|
||
|
|
; Switch to second charset
|
||
|
|
|
||
|
|
lda #14
|
||
|
|
jsr BSOUT
|
||
|
|
|
||
|
|
; Clear the BSS data
|
||
|
|
|
||
|
|
jsr zerobss
|
||
|
|
|
||
|
|
; Save system stuff and setup the stack
|
||
|
|
|
||
|
|
tsx
|
||
|
|
stx spsave ; Save the system stack ptr
|
||
|
|
|
||
|
|
lda $01
|
||
|
|
sta mmusave ; Save the memory configuration
|
||
|
|
lda $01
|
||
|
|
and #$F8
|
||
|
|
ora #$06 ; Enable kernal+I/O, disable basic
|
||
|
|
sta $01
|
||
|
|
|
||
|
|
lda #<$D000
|
||
|
|
sta sp
|
||
|
|
lda #>$D000
|
||
|
|
sta sp+1 ; Set argument stack ptr
|
||
|
|
|
||
|
|
; Initialize the heap
|
||
|
|
|
||
|
|
jsr __hinit
|
||
|
|
|
||
|
|
; Initialize conio stuff
|
||
|
|
|
||
|
|
jsr initconio
|
||
|
|
|
||
|
|
; Pass an empty command line
|
||
|
|
|
||
|
|
jsr push0 ; argc
|
||
|
|
jsr push0 ; argv
|
||
|
|
|
||
|
|
ldy #4 ; Argument size
|
||
|
|
jsr _main ; call the users code
|
||
|
|
|
||
|
|
; fall thru to exit...
|
||
|
|
|
||
|
|
_exit: jsr doatexit ; call exit functions
|
||
|
|
|
||
|
|
ldx spsave
|
||
|
|
txs ; Restore stack pointer
|
||
|
|
lda mmusave
|
||
|
|
sta $01 ; Restore memory configuration
|
||
|
|
|
||
|
|
; Copy back the zero page stuff
|
||
|
|
|
||
|
|
ldy #zpspace-1
|
||
|
|
L2: lda zpsave,y
|
||
|
|
sta sp,y
|
||
|
|
dey
|
||
|
|
bpl L2
|
||
|
|
|
||
|
|
; Reset changed vectors, back to basic
|
||
|
|
|
||
|
|
jmp RESTOR
|
||
|
|
|
||
|
|
|
||
|
|
.data
|
||
|
|
|
||
|
|
zpsave: .res zpspace
|
||
|
|
|
||
|
|
.bss
|
||
|
|
|
||
|
|
spsave: .res 1
|
||
|
|
mmusave:.res 1
|