;
-; Startup code for cc65 (Apple2 version)
+; Oliver Schmidt, 15.09.2009
;
-; This must be the *first* file on the linker command line
+; Startup code for cc65 (Apple2 version)
;
- .export _exit
- .import initlib, donelib
- .import zerobss, push0
- .import _main
+ .export _exit, done, return
+ .export __STARTUP__ : absolute = 1 ; Mark as startup
+ .import zerobss
+ .import initlib, donelib
+ .import callmain, callirq
+ .import __RAM_START__ , __RAM_LAST__ ; Linker generated
+ .import __MOVE_START__, __MOVE_LAST__ ; Linker generated
+ .import __LC_START__ , __LC_LAST__ ; Linker generated
+ .import __ZPSAVE_RUN__, __INIT_SIZE__ ; Linker generated
+ .import __INTERRUPTOR_COUNT__ ; Linker generated
.include "zeropage.inc"
- .include "apple2.inc"
-
-; ------------------------------------------------------------------------
-; Actual code
+ .include "apple2.inc"
-.code
+ .linecont +
- ldx #zpspace-1
-L1: lda sp,x
- sta zpsave,x ; Save the zero page locations we need
- dex
- bpl L1
-
-; Clear the BSS data
-
- jsr zerobss
+; ------------------------------------------------------------------------
-; Save system stuff and setup the stack
+ .segment "EXEHDR"
- tsx
- stx spsave ; Save the system stack ptr
+ .addr __RAM_START__ ; Start address
+ .word __ZPSAVE_RUN__ - __RAM_START__ + \
+ __MOVE_LAST__ - __MOVE_START__ ; Size
- lda #<TOPMEM
- sta sp
- lda #>TOPMEM
- sta sp+1 ; Set argument stack ptr
+; ------------------------------------------------------------------------
-; Call module constructors
+ .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."
+ ldx #$FF
+ txs ; Init stack pointer
+
+ ; Switch in LC bank 2 for W/O
+ bit $C081
+ bit $C081
+
+ ; Set source start address
+ lda #<(__ZPSAVE_RUN__ + __INIT_SIZE__)
+ ldy #>(__ZPSAVE_RUN__ + __INIT_SIZE__)
+ sta $9B
+ sty $9C
+
+ ; Set source last address
+ lda #<(__ZPSAVE_RUN__ + __INIT_SIZE__ + __LC_LAST__ - __LC_START__)
+ ldy #>(__ZPSAVE_RUN__ + __INIT_SIZE__ + __LC_LAST__ - __LC_START__)
+ sta $96
+ sty $97
+
+ ; Set destination last address
+ lda #<__LC_LAST__
+ ldy #>__LC_LAST__
+ sta $94
+ sty $95
+
+ ; Call into Applesoft Block Transfer Utility - which handles zero
+ ; sized blocks well - to move content of the LC memory area
+ jsr $D396 ; BLTU + 3
+
+ ; Set source start address
+ lda #<__ZPSAVE_RUN__
+ ldy #>__ZPSAVE_RUN__
+ sta $9B
+ sty $9C
+
+ ; Set source last address
+ lda #<(__ZPSAVE_RUN__ + __INIT_SIZE__)
+ ldy #>(__ZPSAVE_RUN__ + __INIT_SIZE__)
+ sta $96
+ sty $97
+
+ ; Set destination last address
+ lda #<__RAM_LAST__
+ ldy #>__RAM_LAST__
+ sta $94
+ sty $95
+
+ ; Call into Applesoft Block Transfer Utility - which handles moving
+ ; overlapping blocks upwards well - to move the INIT segment
+ jsr $D396 ; BLTU + 3
+
+ ; Delegate all further processing to keep the STARTUP segment small
+ jsr init
+
+ ; Avoid re-entrance of donelib. This is also the _exit entry
+_exit: ldx #<exit
+ lda #>exit
+ jsr reset ; Setup RESET vector
+
+ ; Switch in ROM in case it wasn't already switched in by a RESET
+ bit $C082
+
+ ; Call module destructors
+ jsr donelib
+
+ ; Check for valid interrupt vector table entry number
+ lda int_num
+ beq exit
+
+ ; Deallocate interrupt vector table entry
+ dec i_param ; Adjust parameter count
+ jsr $BF00 ; MLI call entry point
+ .byte $41 ; Dealloc interrupt
+ .addr i_param
+
+ ; Restore the original RESET vector
+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
+
+ ; We're done
+ jmp (done)
- jsr initlib
+; ------------------------------------------------------------------------
-; Initialize conio stuff
+ .segment "INIT"
+
+ ; Save the zero page locations we need
+init: ldx #zpspace-1
+: lda sp,x
+ sta zpsave,x
+ dex
+ bpl :-
+
+ ; Clear the BSS data
+ jsr zerobss
+
+ ; 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
+
+ ; Check for ProDOS
+ ldy $BF00 ; MLI call entry point
+ cpy #$4C ; Is MLI present? (JMP opcode)
+ bne basic
+
+ ; Check ProDOS system bit map
+ lda $BF6F ; protection for pages $B8 - $BF
+ cmp #%00000001 ; exactly system global page is protected
+ bne basic
+
+ ; No BASIC.SYSTEM so quit to ProDOS dispatcher instead
+ lda #<quit
+ ldx #>quit
+ sta done
+ stx done+1
+
+ ; No BASIC.SYSTEM so use addr of ProDOS system global page
+ lda #<$BF00
+ ldx #>$BF00
+ bne :+ ; Branch always
+
+ ; Get highest available mem addr from BASIC interpreter
+basic: lda HIMEM
+ ldx HIMEM+1
+
+ ; Setup the C stack
+: sta sp
+ stx sp+1
+
+ ; Check for interruptors
+ lda #<__INTERRUPTOR_COUNT__
+ beq :+
+
+ ; Check for ProDOS
+ cpy #$4C ; Is MLI present? (JMP opcode)
+ bne prterr
+
+ ; Allocate interrupt vector table entry
+ jsr $BF00 ; MLI call entry point
+ .byte $40 ; Alloc interrupt
+ .addr i_param
+ bcs prterr
+
+ ; Enable interrupts as old ProDOS versions (i.e. 1.1.1)
+ ; jump to SYS and BIN programs with interrupts disabled
+ cli
+
+ ; Call module constructors
+: jsr initlib
+
+ ; Switch in LC bank 2 for R/O
+ bit $C080
+
+ ; Push arguments and call main()
+ jmp callmain
+
+ ; Print error message and return
+prterr: ldx #msglen-1
+: lda errmsg,x
+ jsr $FDED ; COUT
+ dex
+ bpl :-
+ rts
+
+errmsg: .ifdef __APPLE2ENH__
+ .byte $8D, 't'|$80, 'p'|$80, 'u'|$80, 'r'|$80, 'r'|$80
+ .byte 'e'|$80, 't'|$80, 'n'|$80, 'i'|$80, ' '|$80, 'c'|$80
+ .byte 'o'|$80, 'l'|$80, 'l'|$80, 'a'|$80, ' '|$80, 'o'|$80
+ .byte 't'|$80, ' '|$80, 'd'|$80, 'e'|$80, 'l'|$80, 'i'|$80
+ .byte 'a'|$80, 'F'|$80, $8D
+ .else
+ .byte $8D, 'T'|$80, 'P'|$80, 'U'|$80, 'R'|$80, 'R'|$80
+ .byte 'E'|$80, 'T'|$80, 'N'|$80, 'I'|$80, ' '|$80, 'C'|$80
+ .byte 'O'|$80, 'L'|$80, 'L'|$80, 'A'|$80, ' '|$80, 'O'|$80
+ .byte 'T'|$80, ' '|$80, 'D'|$80, 'E'|$80, 'L'|$80, 'I'|$80
+ .byte 'A'|$80, 'F'|$80, $8D
+ .endif
+
+msglen = * - errmsg
- lda #$ff
- sta TEXTTYP
+; ------------------------------------------------------------------------
-; Set up to use Apple ROM $C000-$CFFF
+ .segment "LOWCODE"
- ;; sta USEROM
+ ; ProDOS TechRefMan, chapter 6.2:
+ ; "Each installed routine must begin with a CLD instruction."
+intptr: cld
-; Pass an empty command line
+ ; Call interruptors and check for success
+ jsr callirq
+ bcc :+
- jsr push0 ; argc
- jsr push0 ; argv
+ ; 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
- ldy #4 ; Argument size
- jsr _main ; call the users code
+ ; ProDOS TechRefMan, chapter 6.2:
+ ; "When a routine that cannot process the interrupt is called,
+ ; it should return (via an RTS) with the cary flag set ..."
+: sec
+ rts
-; Call module destructors. This is also the _exit entry.
+ ; Setup RESET vector
+reset: stx SOFTEV
+ sta SOFTEV+1
+ eor #$A5
+ sta PWREDUP
+return: rts
-_exit: jsr donelib
+ ; Quit to ProDOS dispatcher
+quit: jsr $BF00 ; MLI call entry point
+ .byte $65 ; Quit
+ .word q_param
-; Restore system stuff
+; ------------------------------------------------------------------------
- lda #$ff ; Reset text mode
- sta TEXTTYP
+ .rodata
- ldx spsave
- txs ; Restore stack pointer
+ ; MLI parameter list for quit
+q_param:.byte $04 ; param_count
+ .byte $00 ; quit_type
+ .word $0000 ; reserved
+ .byte $00 ; reserved
+ .word $0000 ; reserved
+
+; ------------------------------------------------------------------------
-; Copy back the zero page stuff
+ .data
- ldx #zpspace-1
-L2: lda zpsave,x
- sta sp,x
- dex
- bpl L2
+ ; MLI parameter list for (de)alloc interrupt
+i_param:.byte $02 ; param_count
+int_num:.byte $00 ; int_num
+ .addr intptr ; int_code
-; Reset changed vectors, back to basic
+ ; Location to jump to when we're done
+done: .addr DOSWARM
- jmp RESTOR
+; ------------------------------------------------------------------------
+ .segment "ZPSAVE"
-.data
+zpsave: .res zpspace
-zpsave: .res zpspace
+; ------------------------------------------------------------------------
-.bss
+ .bss
-spsave: .res 1
+rvsave: .res 3
projects / cc65 / blobdiff