;
; Startup code for cc65 (PET version)
-;
-; This must be the *first* file on the linker command line
;
.export _exit
- .import __hinit, initconio, zerobss, push0, doatexit
- .import _main
-
+ .export __STARTUP__ : absolute = 1 ; Mark as startup
+ .import initlib, donelib, callirq
+ .import zerobss, push0
+ .import callmain
+ .import CLRCH, BSOUT
+ .import __INTERRUPTOR_COUNT__
+
+ .include "zeropage.inc"
.include "pet.inc"
.include "../cbm/cbm.inc"
; ------------------------------------------------------------------------
-; Define and export the ZP variables for the C64 runtime
-
- .exportzp sp, sreg, regsave
- .exportzp ptr1, ptr2, ptr3, ptr4
- .exportzp tmp1, tmp2, tmp3, tmp4
- .exportzp regbank, zpspace
-
-.zeropage
-
-zpstart = *
-sp: .res 2 ; Stack pointer
-sreg: .res 2 ; Secondary register/high 16 bit for longs
-regsave: .res 2 ; slot to save/restore (E)AX into
-ptr1: .res 2
-ptr2: .res 2
-ptr3: .res 2
-ptr4: .res 2
-tmp1: .res 1
-tmp2: .res 1
-tmp3: .res 1
-tmp4: .res 1
-regbank: .res 6 ; 6 byte register bank
-
-zpspace = * - zpstart ; Zero page space allocated
+; Place the startup code in a special segment.
-.code
+.segment "STARTUP"
-; ------------------------------------------------------------------------
; BASIC header with a SYS call
- .org $3FF
.word Head ; Load address
Head: .word @Next
- .word 1000 ; Line number
+ .word .version ; Line number
.byte $9E,"1037" ; SYS 1037
.byte $00 ; End of BASIC line
@Next: .word 0 ; BASIC end marker
- .reloc
; ------------------------------------------------------------------------
; Actual code
ldx #zpspace-1
L1: lda sp,x
- sta zpsave,x ; Save the zero page locations we need
+ sta zpsave,x ; Save the zero page locations we need
dex
bpl L1
jsr CLRCH
-; Switch to second charset
+; Switch to second charset. The routine that is called by BSOUT to switch the
+; character set will use FNLEN as temporary storage - YUCK! Since the
+; initmainargs routine, which parses the command line for arguments needs this
+; information, we need to save and restore it here.
+; Thanks to Stefan Haubenthal for this information!
+ lda FNLEN
+ pha ; Save FNLEN
lda #14
; sta $E84C ; See PET FAQ
jsr BSOUT
+ pla
+ sta FNLEN ; Restore FNLEN
; Clear the BSS data
lda MEMSIZE+1
sta sp+1 ; Set argument stack ptr
-; Initialize the heap
+; If we have IRQ functions, chain our stub into the IRQ vector
- jsr __hinit
+ 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
-; Initialize conio stuff
+; Call module constructors
- jsr initconio
+NoIRQ1: jsr initlib
-; Pass an empty command line
+; Push arguments and call main()
- jsr push0 ; argc
- jsr push0 ; argv
+ jsr callmain
- ldy #4 ; Argument size
- jsr _main ; call the users code
+; Call module destructors. This is also the _exit entry.
-; fall thru to exit...
+_exit: pha ; Save the return code on stack
+ jsr donelib
-_exit: jsr doatexit ; call exit functions
+; Reset the IRQ vector if we chained it.
- ldx spsave
- txs ; Restore stack pointer
+ lda #<__INTERRUPTOR_COUNT__
+ beq NoIRQ2
+ lda IRQInd+1
+ ldx IRQInd+2
+ sei
+ sta IRQVec
+ stx IRQVec+1
+ cli
; Copy back the zero page stuff
- ldx #zpspace-1
+NoIRQ2: ldx #zpspace-1
L2: lda zpsave,x
sta sp,x
dex
bpl L2
+; Store the program return code into ST
+
+ pla
+ sta ST
+
+; Restore the stack pointer
+
+ ldx spsave
+ txs ; Restore stack pointer
+
; Back to basic
rts
+; ------------------------------------------------------------------------
+; 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
projects / cc65 / blobdiff