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Startup code with interruptor support by Oliver Schmidt

git-svn-id: svn://svn.cc65.org/cc65/trunk@3479 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz 2005-04-21 01:41:50 +00:00
parent 9bd3aba923
commit c0f6dea213

View File

@ -4,129 +4,168 @@
; This must be the *first* file on the linker command line
;
.export _exit, __Exit
.import initlib, donelib
.import zerobss
.import __STARTUP_LOAD__, __BSS_LOAD__ ; Linker generated
.import callmain
.export _exit, __Exit
.import zerobss
.import initlib, donelib
.import callmain, callirq
.import __STARTUP_LOAD__, __BSS_LOAD__ ; Linker generated
.import __INTERRUPTOR_COUNT__ ; Linker generated
.include "zeropage.inc"
.include "apple2.inc"
.include "apple2.inc"
.include "mli.inc"
; ------------------------------------------------------------------------
; The executable header
.segment "EXEHDR"
.segment "EXEHDR"
.word __STARTUP_LOAD__ ; Start address
.word __BSS_LOAD__ - __STARTUP_LOAD__ ; Size
.addr __STARTUP_LOAD__ ; Start address
.word __BSS_LOAD__ - __STARTUP_LOAD__ ; Size
; ------------------------------------------------------------------------
; Place the startup code in a special segment.
.segment "STARTUP"
.segment "STARTUP"
; ProDOS TechRefMan, chapter 5.2.1:
; "For maximum interrupt efficiency, a system program should not use more
; than the upper 3/4 of the stack."
; ProDOS TechRefMan, chapter 5.2.1:
; "For maximum interrupt efficiency, a system program should not
; use more than the upper 3/4 of the stack."
ldx #$FF
txs ; Init stack pointer
ldx #$FF
txs ; Init stack pointer
; Delegate all further processing to keep STARTUP small
jsr init
; Save the zero page locations we need
; Avoid re-entrance of donelib. This is also the _exit entry
_exit: ldx #<__Exit
lda #>__Exit
jsr reset ; Setup RESET vector
ldx #zpspace-1
: lda sp,x
sta zpsave,x
dex
bpl :-
; Check for valid interrrupt vector table entry number
lda intnum
beq :+
; Save the original RESET vector
; Deallocate interrupt vector table entry
dec params ; Adjust parameter count
jsr ENTRY
.byte $41 ; Dealloc interrupt
.addr params
ldx #$02
: lda SOFTEV,x
sta rvsave,x
dex
bpl :-
; Call module destructors
: jsr donelib
; ProDOS TechRefMan, chapter 5.3.5:
; "Your system program should place in the RESET vector the address of a
; routine that ... closes the files."
; Restore the original RESET vector. This is also the __Exit entry
__Exit: ldx #$02
: lda rvsave,x
sta SOFTEV,x
dex
bpl :-
ldx #<_exit
lda #>_exit
jsr reset ; Setup RESET vector
; Clear the BSS data
; Copy back the zero page stuff
ldx #zpspace-1
: lda zpsave,x
sta sp,x
dex
bpl :-
jsr zerobss
; ProDOS TechRefMan, chapter 5.2.1:
; "System programs should set the stack pointer to $FF at the
; warm-start entry point."
ldx #$FF
txs ; Re-init stack pointer
; Setup the stack
lda HIMEM
sta sp
lda HIMEM+1
sta sp+1 ; Set argument stack ptr
; Call module constructors
jsr initlib
; Push arguments and call main()
jsr callmain
; Avoid re-entrance of donelib. This is also the _exit entry
_exit: ldx #<__Exit
lda #>__Exit
jsr reset ; Setup RESET vector
; Call module destructors
jsr donelib
; Restore the original RESET vector. This is also the __Exit entry
__Exit: ldx #$02
: lda rvsave,x
sta SOFTEV,x
dex
bpl :-
; Copy back the zero page stuff
ldx #zpspace-1
: lda zpsave,x
sta sp,x
dex
bpl :-
; ProDOS TechRefMan, chapter 5.2.1:
; "System programs should set the stack pointer to $FF at the warm-start
; entry point."
ldx #$FF
txs ; Re-init stack pointer
; Back to DOS
jmp DOSWARM
; Back to DOS
jmp DOSWARM
; ------------------------------------------------------------------------
; Setup RESET vector
reset: stx SOFTEV
sta SOFTEV+1
eor #$A5
sta PWREDUP
rts
.segment "INIT"
; Save the zero page locations we need
init: ldx #zpspace-1
: lda sp,x
sta zpsave,x
dex
bpl :-
; Save the original RESET vector
ldx #$02
: lda SOFTEV,x
sta rvsave,x
dex
bpl :-
; ProDOS TechRefMan, chapter 5.3.5:
; "Your system program should place in the RESET vector the
; address of a routine that ... closes the files."
ldx #<_exit
lda #>_exit
jsr reset ; Setup RESET vector
; Clear the BSS data
jsr zerobss
; Setup the stack
lda HIMEM
sta sp
lda HIMEM+1
sta sp+1 ; Set argument stack ptr
; Call module constructors
jsr initlib
; Check for interruptors
lda #<__INTERRUPTOR_COUNT__
beq :+
; Check for ProDOS
lda ENTRY
cmp #$4C ; Is MLI present? (JMP opcode)
bne :+
; Allocate interrupt vector table entry
jsr ENTRY
.byte $40 ; Alloc interrupt
.addr params
; Push arguments and call main()
: jmp callmain
; ------------------------------------------------------------------------
; Data
.data
.segment "LOWCODE"
zpsave: .res zpspace
; ProDOS TechRefMan, chapter 6.2:
; "Each installed routine must begin with a CLD instruction"
intrpt: cld
rvsave: .res 3
; Call interruptors
jsr callirq
; ProDOS TechRefMan, chapter 6.2:
; "When the routine that can process the interrupt is called, it
; should ... return (via an RTS) with the carry flag clear."
clc
rts
; ------------------------------------------------------------------------
.code
; Setup RESET vector
reset: stx SOFTEV
sta SOFTEV+1
eor #$A5
sta PWREDUP
rts
; ------------------------------------------------------------------------
.data
zpsave: .res zpspace
rvsave: .res 3
params: .byte $02 ; Parameter count
intnum: .byte $00 ; Interrupt number
.addr intrpt ; Interrupt handler