cc65/libsrc/osic1p/crt0.s

; ---------------------------------------------------------------------------
; crt0.s
; ---------------------------------------------------------------------------
;
; Startup code for Ohio Scientific Challenger 1P

.export   _init, _exit
.import   _main

.export   __STARTUP__ : absolute = 1    ; Mark as startup
.import   __RAM_START__, __RAM_SIZE__   ; Linker generated
.import   __STACKSIZE__

.import    zerobss, initlib, donelib

.include  "zeropage.inc"
.include  "extzp.inc"
.include  "osic1p.inc"

; ---------------------------------------------------------------------------
; Place the startup code in a special segment

.segment  "STARTUP"

; ---------------------------------------------------------------------------
; A little light 6502 housekeeping

_init:    ldx     #$FF          ; Initialize stack pointer to $01FF
          txs
          cld                   ; Clear decimal mode

; ---------------------------------------------------------------------------
; Set cc65 argument stack pointer

          lda     #<(__RAM_START__ + __RAM_SIZE__  + __STACKSIZE__)
          sta     sp
          lda     #>(__RAM_START__ + __RAM_SIZE__  + __STACKSIZE__)
          sta     sp+1

; ---------------------------------------------------------------------------
; Initialize memory storage

          jsr     zerobss       ; Clear BSS segment
          jsr     initlib       ; Run constructors

; ---------------------------------------------------------------------------
; Call main()

          jsr     _main

; ---------------------------------------------------------------------------
; Back from main (this is also the _exit entry):

_exit:    jsr     donelib       ; Run destructors
          jmp     RESET         ; Display boot menu after program exit
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00			`; ---------------------------------------------------------------------------`
			`; crt0.s`
			`; ---------------------------------------------------------------------------`
			`;`
			`; Startup code for Ohio Scientific Challenger 1P`

			`.export _init, _exit`
			`.import _main`

Incorporated another round of feedback for pull request. Adjusted comment formatting in several assembler files. Removed dummy kbhit() function, as it's better to get a linker error than an implementation that does the wrong thing. 2015-02-18 17:38:42 +00:00			`.export __STARTUP__ : absolute = 1 ; Mark as startup`
			`.import __RAM_START__, __RAM_SIZE__ ; Linker generated`
Fix wrong expression for top of C stack. Thanks to Greg King for this fix. 2015-02-25 22:48:57 +00:00			`.import __STACKSIZE__`
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00
Remove unneeded import 2013-07-24 20:35:58 +00:00			`.import zerobss, initlib, donelib`
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00
			`.include "zeropage.inc"`
Enhancements for cursor calculation Fix handling of newlines. Wrap around to top of screen when newline occurs in last line. Initialize screen width in crt0.s. 2014-11-23 14:32:48 +00:00			`.include "extzp.inc"`
Jump to boot prompt after main program exits. 2015-02-05 22:21:59 +00:00			`.include "osic1p.inc"`
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00
			`; ---------------------------------------------------------------------------`
			`; Place the startup code in a special segment`

			`.segment "STARTUP"`

			`; ---------------------------------------------------------------------------`
			`; A little light 6502 housekeeping`

Incorporated another round of feedback for pull request. Adjusted comment formatting in several assembler files. Removed dummy kbhit() function, as it's better to get a linker error than an implementation that does the wrong thing. 2015-02-18 17:38:42 +00:00			`_init: ldx #$FF ; Initialize stack pointer to $01FF`
Adapted to cc65 assembler coding conventions Assembler statements are written in lowercase. 2015-01-05 20:28:39 +00:00			`txs`
Incorporated another round of feedback for pull request. Adjusted comment formatting in several assembler files. Removed dummy kbhit() function, as it's better to get a linker error than an implementation that does the wrong thing. 2015-02-18 17:38:42 +00:00			`cld ; Clear decimal mode`
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00
			`; ---------------------------------------------------------------------------`
			`; Set cc65 argument stack pointer`

Fix wrong expression for top of C stack. Thanks to Greg King for this fix. 2015-02-25 22:48:57 +00:00			`lda #<(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)`
Adapted to cc65 assembler coding conventions Assembler statements are written in lowercase. 2015-01-05 20:28:39 +00:00			`sta sp`
Fix wrong expression for top of C stack. Thanks to Greg King for this fix. 2015-02-25 22:48:57 +00:00			`lda #>(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)`
Adapted to cc65 assembler coding conventions Assembler statements are written in lowercase. 2015-01-05 20:28:39 +00:00			`sta sp+1`
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00
			`; ---------------------------------------------------------------------------`
			`; Initialize memory storage`

Incorporated another round of feedback for pull request. Adjusted comment formatting in several assembler files. Removed dummy kbhit() function, as it's better to get a linker error than an implementation that does the wrong thing. 2015-02-18 17:38:42 +00:00			`jsr zerobss ; Clear BSS segment`
			`jsr initlib ; Run constructors`
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00
			`; ---------------------------------------------------------------------------`
			`; Call main()`

Adapted to cc65 assembler coding conventions Assembler statements are written in lowercase. 2015-01-05 20:28:39 +00:00			`jsr _main`
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00
			`; ---------------------------------------------------------------------------`
Incorporated another round of feedback for pull request. Adjusted comment formatting in several assembler files. Removed dummy kbhit() function, as it's better to get a linker error than an implementation that does the wrong thing. 2015-02-18 17:38:42 +00:00			`; Back from main (this is also the _exit entry):`
Nominal support for target Ohio Scientific Challenger 1P 2013-07-14 20:50:38 +00:00
Incorporated another round of feedback for pull request. Adjusted comment formatting in several assembler files. Removed dummy kbhit() function, as it's better to get a linker error than an implementation that does the wrong thing. 2015-02-18 17:38:42 +00:00			`_exit: jsr donelib ; Run destructors`
			`jmp RESET ; Display boot menu after program exit`