60bc009991
named EXEHDR. * Renamed BASICHDR to EXEHDR for the PET-II machines. * Moved the call to CHRCH in front of the code that saves the zero page, since open files are sometimes remembered in the zero page, so we need to close them before we grab a copy. git-svn-id: svn://svn.cc65.org/cc65/trunk@4507 b7a2c559-68d2-44c3-8de9-860c34a00d81
165 lines
3.3 KiB
ArmAsm
165 lines
3.3 KiB
ArmAsm
;
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; Startup code for cc65 (PET version)
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;
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.export _exit
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.export __STARTUP__ : absolute = 1 ; Mark as startup
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.import initlib, donelib, callirq
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.import zerobss, push0
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.import callmain
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.import CLRCH, BSOUT
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.import __INTERRUPTOR_COUNT__
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.include "zeropage.inc"
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.include "pet.inc"
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.include "../cbm/cbm.inc"
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; ------------------------------------------------------------------------
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; BASIC header with a SYS call
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.segment "EXEHDR"
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.word Head ; Load address
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Head: .word @Next
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.word .version ; Line number
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.byte $9E ; SYS token
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.byte <(((Start / 1000) .mod 10) + $30)
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.byte <(((Start / 100) .mod 10) + $30)
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.byte <(((Start / 10) .mod 10) + $30)
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.byte <(((Start / 1) .mod 10) + $30)
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.byte $00 ; End of BASIC line
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@Next: .word 0 ; BASIC end marker
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; ------------------------------------------------------------------------
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; Startup code
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.segment "STARTUP"
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Start:
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; Close open files
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jsr CLRCH
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; Save the zero page locations we need
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ldx #zpspace-1
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L1: lda sp,x
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sta zpsave,x
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dex
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bpl L1
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; Switch to second charset. The routine that is called by BSOUT to switch the
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; character set will use FNLEN as temporary storage - YUCK! Since the
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; initmainargs routine, which parses the command line for arguments needs this
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; information, we need to save and restore it here.
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; Thanks to Stefan Haubenthal for this information!
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lda FNLEN
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pha ; Save FNLEN
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lda #14
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; sta $E84C ; See PET FAQ
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jsr BSOUT
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pla
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sta FNLEN ; Restore FNLEN
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; Clear the BSS data
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jsr zerobss
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; Save system stuff and setup the stack
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tsx
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stx spsave ; Save the system stack ptr
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lda MEMSIZE
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sta sp
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lda MEMSIZE+1
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sta sp+1 ; Set argument stack ptr
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; If we have IRQ functions, chain our stub into the IRQ vector
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lda #<__INTERRUPTOR_COUNT__
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beq NoIRQ1
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lda IRQVec
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ldx IRQVec+1
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sta IRQInd+1
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stx IRQInd+2
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lda #<IRQStub
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ldx #>IRQStub
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sei
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sta IRQVec
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stx IRQVec+1
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cli
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; Call module constructors
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NoIRQ1: jsr initlib
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; Push arguments and call main()
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jsr callmain
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; Call module destructors. This is also the _exit entry.
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_exit: pha ; Save the return code on stack
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jsr donelib
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; Reset the IRQ vector if we chained it.
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lda #<__INTERRUPTOR_COUNT__
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beq NoIRQ2
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lda IRQInd+1
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ldx IRQInd+2
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sei
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sta IRQVec
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stx IRQVec+1
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cli
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; Copy back the zero page stuff
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NoIRQ2: ldx #zpspace-1
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L2: lda zpsave,x
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sta sp,x
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dex
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bpl L2
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; Store the program return code into ST
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pla
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sta ST
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; Restore the stack pointer
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ldx spsave
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txs ; Restore stack pointer
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; Back to basic
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rts
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; ------------------------------------------------------------------------
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; The IRQ vector jumps here, if condes routines are defined with type 2.
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IRQStub:
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cld ; Just to be sure
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jsr callirq ; Call the functions
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jmp IRQInd ; Jump to the saved IRQ vector
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; ------------------------------------------------------------------------
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; Data
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.data
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IRQInd: jmp $0000
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.segment "ZPSAVE"
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zpsave: .res zpspace
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.bss
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spsave: .res 1
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mmusave:.res 1
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