1
0
mirror of https://github.com/cc65/cc65.git synced 2024-12-30 05:30:41 +00:00
cc65/libsrc/atmos/crt0.s
cuz 3b3e1bec17 Removed the empty LOWCODE segments from the startup files. This is now
handled by the OPTIONAL segment attribute in the linker config.


git-svn-id: svn://svn.cc65.org/cc65/trunk@2164 b7a2c559-68d2-44c3-8de9-860c34a00d81
2003-05-22 22:32:04 +00:00

112 lines
2.3 KiB
ArmAsm

;
; Startup code for cc65 (Oric version)
;
; By Debrune Jérôme <jede@oric.org> and Ullrich von Bassewitz <uz@cc65.org>
;
; This must be the *first* file on the linker command line
;
.export _exit
.import initlib, donelib
.import callmain, zerobss
.import __RAM_START__, __RAM_SIZE__, __RAM_LAST__
.include "zeropage.inc"
.include "atmos.inc"
; ------------------------------------------------------------------------
; Oric tape header
.segment "TAPEHDR"
.byte $16, $16, $16 ; Sync bytes
.byte $24 ; End of header marker
.byte $00 ; $2B0
.byte $00 ; $2AF
.byte $80 ; $2AE Machine code flag
.byte $C7 ; $2AD Autoload flag
.dbyt __RAM_START__ + __RAM_LAST__ ; $2AB
.dbyt __RAM_START__ ; $2A9
.byte $00 ; $2A8
.byte $00 ; Zero terminated name
; ------------------------------------------------------------------------
; Place the startup code in a special segment.
.segment "STARTUP"
; Save the zero page area we're about to use
ldx #zpspace-1
L1: lda sp,x
sta zpsave,x ; Save the zero page locations we need
dex
bpl L1
; Clear the BSS data
jsr zerobss
; Unprotect columns 0 and 1
lda STATUS
sta stsave
and #%11011111
sta STATUS
; Save system stuff and setup the stack
tsx
stx spsave ; save system stk ptr
lda #<(__RAM_START__ + __RAM_SIZE__)
sta sp
lda #>(__RAM_START__ + __RAM_SIZE__)
sta sp+1 ; Set argument stack ptr
; Call module constructors
jsr initlib
; Push arguments and call main()
jsr callmain
; Call module destructors. This is also the _exit entry.
_exit: jsr donelib ; Run module destructors
; Restore system stuff
ldx spsave
txs
lda stsave
sta STATUS
; Copy back the zero page stuff
ldx #zpspace-1
L2: lda zpsave,x
sta sp,x
dex
bpl L2
; Back to BASIC
rts
; ------------------------------------------------------------------------
; Data
.data
zpsave: .res zpspace
.bss
spsave: .res 1
stsave: .res 1