mirror of
https://github.com/cc65/cc65.git
synced 2024-11-11 01:05:25 +00:00
da59130820
loadaddr and exehdr modules. git-svn-id: svn://svn.cc65.org/cc65/trunk@4871 b7a2c559-68d2-44c3-8de9-860c34a00d81
143 lines
2.6 KiB
ArmAsm
143 lines
2.6 KiB
ArmAsm
;
|
|
; Startup code for cc65 (C16 version)
|
|
;
|
|
; Note: The C16 is actually the Plus/4 with just 16KB of memory. So many
|
|
; things are similar here, and we even use the plus4.inc include file.
|
|
;
|
|
|
|
.export _exit
|
|
.export __STARTUP__ : absolute = 1 ; Mark as startup
|
|
.import initlib, donelib, callirq
|
|
.import callmain, zerobss
|
|
.import MEMTOP, RESTOR, BSOUT, CLRCH
|
|
.import __INTERRUPTOR_COUNT__
|
|
|
|
.include "zeropage.inc"
|
|
.include "plus4.inc"
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Startup code
|
|
|
|
.segment "STARTUP"
|
|
|
|
Start:
|
|
|
|
; Save the zero page locations we need
|
|
|
|
ldx #zpspace-1
|
|
L1: lda sp,x
|
|
sta zpsave,x
|
|
dex
|
|
bpl L1
|
|
|
|
; 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 system stk ptr
|
|
|
|
sec
|
|
jsr MEMTOP ; Get top memory
|
|
cpy #$80 ; We can only use the low 32K :-(
|
|
bcc MemOk
|
|
ldy #$80
|
|
ldx #$00
|
|
MemOk: stx sp
|
|
sty sp+1 ; set argument stack ptr
|
|
|
|
; If we have IRQ functions, chain our stub into the IRQ vector
|
|
|
|
lda #<__INTERRUPTOR_COUNT__
|
|
beq NoIRQ1
|
|
lda IRQVec
|
|
ldx IRQVec+1
|
|
sta IRQInd+1
|
|
stx IRQInd+2
|
|
lda #<IRQStub
|
|
ldx #>IRQStub
|
|
sei
|
|
sta IRQVec
|
|
stx IRQVec+1
|
|
cli
|
|
|
|
; Call module constructors
|
|
|
|
NoIRQ1: jsr initlib
|
|
|
|
; Push arguments and call main()
|
|
|
|
jsr callmain
|
|
|
|
; Call module destructors. This is also the _exit entry.
|
|
|
|
_exit: pha ; Save the return code on stack
|
|
jsr donelib ; Run module destructors
|
|
|
|
; Reset the IRQ vector if we chained it.
|
|
|
|
pha ; Save the return code on stack
|
|
lda #<__INTERRUPTOR_COUNT__
|
|
beq NoIRQ2
|
|
lda IRQInd+1
|
|
ldx IRQInd+2
|
|
sei
|
|
sta IRQVec
|
|
stx IRQVec+1
|
|
cli
|
|
|
|
; Copy back the zero page stuff
|
|
|
|
NoIRQ2: ldx #zpspace-1
|
|
L2: lda zpsave,x
|
|
sta sp,x
|
|
dex
|
|
bpl L2
|
|
|
|
; Store the return code into ST
|
|
|
|
pla
|
|
sta ST
|
|
|
|
; Restore the stack pointer
|
|
|
|
ldx spsave
|
|
txs
|
|
|
|
; Reset changed vectors
|
|
|
|
jmp RESTOR
|
|
|
|
; ------------------------------------------------------------------------
|
|
; The IRQ vector jumps here, if condes routines are defined with type 2.
|
|
|
|
IRQStub:
|
|
cld ; Just to be sure
|
|
jsr callirq ; Call the functions
|
|
jmp IRQInd ; Jump to the saved IRQ vector
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Data
|
|
|
|
.data
|
|
|
|
IRQInd: jmp $0000
|
|
|
|
.segment "ZPSAVE"
|
|
|
|
zpsave: .res zpspace
|
|
|
|
.bss
|
|
|
|
spsave: .res 1
|
|
|
|
|