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cc65/libsrc/kim1/crt0.s
Jeff Tranter 806ffe5675 Fixes and improvements to KIM-1 i/o routines.
Tested on real KIM-1 hardware.

read.s:
- Remove commented out line.
- Remove unused check for bell character.
- Remove echo of newline (hardware always echoes entered characters).
- This fixes gets() and fgets() so they return when CR is entered.

write.s:
- Fix check for adding return after linefeed (failed to work because OUTCHR changes A)
- Remove unused check for bell character.

kim1.inc:
- Add symbol for monitor entry

crt0.s:
- Jump to KIM-1 monitor by address rather than using BRK (which relies on vector being set in RAM)
2023-03-27 17:56:25 -04:00

46 lines
1.1 KiB
ArmAsm

;
; Startup code for cc65 (KIM-1 version)
;
.export _init, _exit
.export __STARTUP__ : absolute = 1 ; Mark as startup
.import _main
.import initlib, donelib, copydata, zerobss
.import __RAM_START__, __RAM_SIZE__ ; Linker generated
.import __STACKSIZE__ ; Linker generated
.include "zeropage.inc"
.include "kim1.inc"
; Place the startup code in a special segment
.segment "STARTUP"
; A little light housekeeping
_init: cld ; Clear decimal mode
; Set cc65 argument stack pointer
lda #<(__RAM_START__ + __RAM_SIZE__)
sta sp
lda #>(__RAM_START__ + __RAM_SIZE__)
sta sp+1
; Initialize memory storage
jsr zerobss ; Clear BSS segment
jsr copydata ; Initialize DATA segment
jsr initlib ; Run constructors
; Call main()
jsr _main
; Back from main (this is also the _exit entry). Jumps to the KIM-1 monitor.
_exit: jmp START