2000-05-28 13:40:48 +00:00
|
|
|
;
|
|
|
|
; Startup code for cc65 (C128 version)
|
|
|
|
;
|
|
|
|
; This must be the *first* file on the linker command line
|
|
|
|
;
|
|
|
|
|
2001-09-13 15:27:19 +00:00
|
|
|
.export _exit
|
2004-04-04 14:28:57 +00:00
|
|
|
.import callirq, initlib, donelib
|
2002-12-19 22:53:13 +00:00
|
|
|
.import zerobss
|
2003-03-10 21:21:46 +00:00
|
|
|
.import push0, callmain
|
2002-11-19 23:02:47 +00:00
|
|
|
.import RESTOR, BSOUT, CLRCH
|
2004-04-04 14:28:57 +00:00
|
|
|
.import __IRQFUNC_COUNT__
|
2001-09-13 15:27:19 +00:00
|
|
|
.import __RAM_START__, __RAM_SIZE__
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2002-05-26 09:09:10 +00:00
|
|
|
.include "zeropage.inc"
|
2001-09-13 15:27:19 +00:00
|
|
|
.include "c128.inc"
|
2002-11-19 23:02:47 +00:00
|
|
|
|
2001-09-13 15:27:19 +00:00
|
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
|
|
; Constants
|
|
|
|
|
|
|
|
IRQInd = $2FD ; JMP $0000 - used as indirect IRQ vector
|
2000-05-28 13:40:48 +00:00
|
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
2001-10-25 19:13:36 +00:00
|
|
|
; Place the startup code in a special segment to cope with the quirks of
|
2002-11-22 00:52:49 +00:00
|
|
|
; c128 banking.
|
2001-10-25 19:13:36 +00:00
|
|
|
|
|
|
|
.segment "STARTUP"
|
2000-05-28 13:40:48 +00:00
|
|
|
|
|
|
|
; BASIC header with a SYS call
|
|
|
|
|
|
|
|
.org $1BFF
|
|
|
|
.word Head ; Load address
|
|
|
|
Head: .word @Next
|
2004-02-02 13:34:12 +00:00
|
|
|
.word .version ; Line number
|
2000-05-28 13:40:48 +00:00
|
|
|
.byte $9E,"7181" ; SYS 7181
|
|
|
|
.byte $00 ; End of BASIC line
|
|
|
|
@Next: .word 0 ; BASIC end marker
|
|
|
|
.reloc
|
|
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
|
|
; Actual code
|
|
|
|
|
|
|
|
; Close open files
|
|
|
|
|
|
|
|
jsr CLRCH
|
|
|
|
|
2001-10-26 13:48:49 +00:00
|
|
|
; Switch to the second charset
|
2000-05-28 13:40:48 +00:00
|
|
|
|
|
|
|
lda #14
|
|
|
|
jsr BSOUT
|
|
|
|
|
2001-10-26 13:48:49 +00:00
|
|
|
; Before doing anything else, we have to setup our banking configuration.
|
|
|
|
; Otherwise just the lowest 16K are actually RAM. Writing through the ROM
|
|
|
|
; to the underlying RAM works, but it is bad style.
|
2000-05-28 13:40:48 +00:00
|
|
|
|
|
|
|
lda MMU_CR ; Get current memory configuration...
|
|
|
|
pha ; ...and save it for later
|
2002-12-02 14:12:25 +00:00
|
|
|
lda #MMU_CFG_CC65 ; Bank0 with kernal ROM
|
2001-09-13 15:27:19 +00:00
|
|
|
sta MMU_CR
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2001-10-26 13:48:49 +00:00
|
|
|
; Save the zero page locations we need
|
|
|
|
|
|
|
|
ldx #zpspace-1
|
|
|
|
L1: lda sp,x
|
|
|
|
sta zpsave,x
|
|
|
|
dex
|
|
|
|
bpl L1
|
|
|
|
|
2000-05-28 13:40:48 +00:00
|
|
|
; Clear the BSS data
|
|
|
|
|
|
|
|
jsr zerobss
|
|
|
|
|
|
|
|
; Save system stuff and setup the stack
|
|
|
|
|
|
|
|
pla ; Get MMU setting
|
|
|
|
sta mmusave
|
|
|
|
|
|
|
|
tsx
|
2001-10-26 13:48:49 +00:00
|
|
|
stx spsave ; Save the system stack pointer
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2001-09-13 15:27:19 +00:00
|
|
|
lda #<(__RAM_START__ + __RAM_SIZE__)
|
|
|
|
sta sp
|
|
|
|
lda #>(__RAM_START__ + __RAM_SIZE__)
|
|
|
|
sta sp+1 ; Set argument stack ptr
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2000-11-22 22:19:09 +00:00
|
|
|
; Call module constructors
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2000-11-22 22:19:09 +00:00
|
|
|
jsr initlib
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2004-04-28 09:47:57 +00:00
|
|
|
; Set the bank for the file name to our execution bank. We must do this,
|
|
|
|
; *after* calling constructors, because some of them may depend on the
|
|
|
|
; original value of this register.
|
|
|
|
|
|
|
|
lda #0
|
|
|
|
sta FNAM_BANK
|
|
|
|
|
2001-09-13 15:27:19 +00:00
|
|
|
; If we have IRQ functions, chain our stub into the IRQ vector
|
|
|
|
|
|
|
|
lda #<__IRQFUNC_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
|
|
|
|
|
2003-03-10 21:21:46 +00:00
|
|
|
; Push arguments and call main()
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2003-03-10 21:21:46 +00:00
|
|
|
NoIRQ1: jsr callmain
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2004-03-08 20:38:58 +00:00
|
|
|
; Back from main (this is also the _exit entry). Reset the IRQ vector if we
|
2004-03-02 17:08:07 +00:00
|
|
|
; chained it.
|
2001-09-13 15:27:19 +00:00
|
|
|
|
2004-03-02 17:08:07 +00:00
|
|
|
_exit: pha ; Save the return code on stack
|
2004-03-02 16:59:52 +00:00
|
|
|
lda #<__IRQFUNC_COUNT__
|
2001-09-13 15:27:19 +00:00
|
|
|
beq NoIRQ2
|
|
|
|
lda IRQInd+1
|
|
|
|
ldx IRQInd+2
|
|
|
|
sei
|
|
|
|
sta IRQVec
|
|
|
|
stx IRQVec+1
|
|
|
|
cli
|
|
|
|
|
|
|
|
; Run module destructors
|
2000-05-28 13:40:48 +00:00
|
|
|
|
2001-09-13 15:27:19 +00:00
|
|
|
NoIRQ2: jsr donelib
|
2000-05-28 13:40:48 +00:00
|
|
|
|
|
|
|
; Copy back the zero page stuff
|
|
|
|
|
2000-10-30 21:02:49 +00:00
|
|
|
ldx #zpspace-1
|
|
|
|
L2: lda zpsave,x
|
|
|
|
sta sp,x
|
|
|
|
dex
|
2000-05-28 13:40:48 +00:00
|
|
|
bpl L2
|
|
|
|
|
2004-03-02 17:08:07 +00:00
|
|
|
; Place the program return code into ST
|
|
|
|
|
|
|
|
pla
|
|
|
|
sta ST
|
|
|
|
|
2004-03-08 20:38:58 +00:00
|
|
|
; Reset the stack and the memory configuration
|
|
|
|
|
|
|
|
ldx spsave
|
|
|
|
txs
|
|
|
|
ldx mmusave
|
|
|
|
stx MMU_CR
|
|
|
|
|
2001-10-26 13:48:49 +00:00
|
|
|
; Done, restore kernal vectors in an attempt to cleanup
|
2000-05-28 13:40:48 +00:00
|
|
|
|
|
|
|
jmp RESTOR
|
|
|
|
|
2001-09-13 15:27:19 +00:00
|
|
|
; ------------------------------------------------------------------------
|
|
|
|
; The C128 has ROM parallel to the RAM starting from $4000. The startup code
|
|
|
|
; above will change this setting so that we have RAM from $0000-$BFFF. This
|
|
|
|
; works quite well with the exception of interrupts: The interrupt handler
|
|
|
|
; is in ROM, and the ROM switches back to the ROM configuration, which means
|
2002-11-22 00:52:49 +00:00
|
|
|
; that parts of our program may not be accessible. To solve this, we place
|
|
|
|
; the following code into a special segment called "LOWCODE" which will be
|
|
|
|
; placed just above the startup code, so it goes into a RAM area that is
|
|
|
|
; not banked.
|
|
|
|
|
|
|
|
.segment "LOWCODE"
|
2001-09-13 15:27:19 +00:00
|
|
|
|
|
|
|
IRQStub:
|
2001-10-26 13:48:49 +00:00
|
|
|
cld ; Just to be sure
|
|
|
|
lda MMU_CR ; Get old register value
|
|
|
|
pha ; And save on stack
|
2002-12-02 14:12:25 +00:00
|
|
|
lda #MMU_CFG_CC65 ; Bank 0 with kernal ROM
|
2001-09-13 15:27:19 +00:00
|
|
|
sta MMU_CR
|
2004-04-04 14:28:57 +00:00
|
|
|
jsr callirq ; Call the functions
|
2001-09-13 15:27:19 +00:00
|
|
|
pla ; Get old register value
|
|
|
|
sta MMU_CR
|
2002-11-22 00:52:49 +00:00
|
|
|
jmp IRQInd ; Jump to the saved IRQ vector
|
2001-09-13 15:27:19 +00:00
|
|
|
|
|
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
|
|
; Data
|
|
|
|
|
2000-05-28 13:40:48 +00:00
|
|
|
.data
|
|
|
|
zpsave: .res zpspace
|
|
|
|
|
|
|
|
.bss
|
|
|
|
spsave: .res 1
|
|
|
|
mmusave:.res 1
|
|
|
|
|
|
|
|
|
|
|
|
|