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   __MAIN_START__, __MAIN_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     #<(__MAIN_START__ + __MAIN_SIZE__  + __STACKSIZE__)
          ldx     #>(__MAIN_START__ + __MAIN_SIZE__  + __STACKSIZE__)
          sta     sp
          stx     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`
Renamed RAM to MAIN for all disk based targets. The name RAM doesn't make much sense in general for a memeory area because i.e. the zero page is for sure RAM but is not part of the memory area named RAM. For disk based targets it makes sense to put the disk file more into focus and here MAIN means the main part of the file - in contrast to some header. Only for ROM based targets the name RAM is kept as it makes sense to focus on the difference between RAM and ROM. 2016-03-07 00:28:55 +00:00			`.import __MAIN_START__, __MAIN_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`

Renamed RAM to MAIN for all disk based targets. The name RAM doesn't make much sense in general for a memeory area because i.e. the zero page is for sure RAM but is not part of the memory area named RAM. For disk based targets it makes sense to put the disk file more into focus and here MAIN means the main part of the file - in contrast to some header. Only for ROM based targets the name RAM is kept as it makes sense to focus on the difference between RAM and ROM. 2016-03-07 00:28:55 +00:00			`lda #<(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)`
			`ldx #>(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)`
Adapted to cc65 assembler coding conventions Assembler statements are written in lowercase. 2015-01-05 20:28:39 +00:00			`sta sp`
Renamed RAM to MAIN for all disk based targets. The name RAM doesn't make much sense in general for a memeory area because i.e. the zero page is for sure RAM but is not part of the memory area named RAM. For disk based targets it makes sense to put the disk file more into focus and here MAIN means the main part of the file - in contrast to some header. Only for ROM based targets the name RAM is kept as it makes sense to focus on the difference between RAM and ROM. 2016-03-07 00:28:55 +00:00			`stx 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`