mirror of
https://github.com/cc65/cc65.git
synced 2024-12-26 08:32:00 +00:00
312 lines
8.5 KiB
ArmAsm
312 lines
8.5 KiB
ArmAsm
;
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; Startup code for cc65 (Apple2 version)
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;
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.export _exit, done, return
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.export __STARTUP__ : absolute = 1 ; Mark as startup
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.import zerobss
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.import initlib, donelib
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.import callmain, callirq
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.import __RAM_START__ , __RAM_LAST__ ; Linker generated
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.import __MOVE_START__, __MOVE_LAST__ ; Linker generated
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.import __LC_START__ , __LC_LAST__ ; Linker generated
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.import __ZPSAVE_RUN__, __INIT_SIZE__ ; Linker generated
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.import __INTERRUPTOR_COUNT__ ; Linker generated
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.include "zeropage.inc"
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.include "apple2.inc"
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.linecont +
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; ------------------------------------------------------------------------
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.segment "EXEHDR"
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.addr __RAM_START__ ; Start address
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.word __ZPSAVE_RUN__ - __RAM_START__ + \
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__MOVE_LAST__ - __MOVE_START__ ; Size
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; ------------------------------------------------------------------------
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.segment "STARTUP"
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; ProDOS TechRefMan, chapter 5.2.1:
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; "For maximum interrupt efficiency, a system program should not
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; use more than the upper 3/4 of the stack."
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ldx #$FF
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txs ; Init stack pointer
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; Switch in LC bank 2 for W/O
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bit $C081
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bit $C081
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; Set source start address
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lda #<(__ZPSAVE_RUN__ + __INIT_SIZE__)
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ldy #>(__ZPSAVE_RUN__ + __INIT_SIZE__)
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sta $9B
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sty $9C
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; Set source last address
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lda #<(__ZPSAVE_RUN__ + __INIT_SIZE__ + __LC_LAST__ - __LC_START__)
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ldy #>(__ZPSAVE_RUN__ + __INIT_SIZE__ + __LC_LAST__ - __LC_START__)
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sta $96
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sty $97
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; Set destination last address
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lda #<__LC_LAST__
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ldy #>__LC_LAST__
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sta $94
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sty $95
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; Call into Applesoft Block Transfer Utility - which handles zero
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; sized blocks well - to move content of the LC memory area
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jsr $D396 ; BLTU + 3
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; Set source start address
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lda #<__ZPSAVE_RUN__
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ldy #>__ZPSAVE_RUN__
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sta $9B
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sty $9C
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; Set source last address
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lda #<(__ZPSAVE_RUN__ + __INIT_SIZE__)
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ldy #>(__ZPSAVE_RUN__ + __INIT_SIZE__)
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sta $96
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sty $97
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; Set destination last address
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lda #<__RAM_LAST__
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ldy #>__RAM_LAST__
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sta $94
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sty $95
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; Call into Applesoft Block Transfer Utility - which handles moving
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; overlapping blocks upwards well - to move the INIT segment
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jsr $D396 ; BLTU + 3
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; Delegate all further processing to keep the STARTUP segment small
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jsr init
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; Avoid re-entrance of donelib. This is also the _exit entry
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_exit: ldx #<exit
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lda #>exit
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jsr reset ; Setup RESET vector
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; Switch in ROM in case it wasn't already switched in by a RESET
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bit $C082
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; Call module destructors
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jsr donelib
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; Check for valid interrupt vector table entry number
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lda int_num
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beq exit
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; Deallocate interrupt vector table entry
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dec i_param ; Adjust parameter count
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jsr $BF00 ; MLI call entry point
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.byte $41 ; Dealloc interrupt
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.addr i_param
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; Restore the original RESET vector
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exit: ldx #$02
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: lda rvsave,x
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sta SOFTEV,x
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dex
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bpl :-
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; Copy back the zero page stuff
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ldx #zpspace-1
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: lda zpsave,x
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sta sp,x
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dex
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bpl :-
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; ProDOS TechRefMan, chapter 5.2.1:
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; "System programs should set the stack pointer to $FF at the
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; warm-start entry point."
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ldx #$FF
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txs ; Re-init stack pointer
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; We're done
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jmp (done)
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; ------------------------------------------------------------------------
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.segment "INIT"
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; Save the zero page locations we need
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init: ldx #zpspace-1
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: lda sp,x
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sta zpsave,x
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dex
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bpl :-
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; Clear the BSS data
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jsr zerobss
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; Save the original RESET vector
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ldx #$02
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: lda SOFTEV,x
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sta rvsave,x
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dex
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bpl :-
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; ProDOS TechRefMan, chapter 5.3.5:
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; "Your system program should place in the RESET vector the
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; address of a routine that ... closes the files."
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ldx #<_exit
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lda #>_exit
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jsr reset ; Setup RESET vector
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; Check for ProDOS
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ldy $BF00 ; MLI call entry point
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cpy #$4C ; Is MLI present? (JMP opcode)
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bne basic
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; Check ProDOS system bit map
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lda $BF6F ; protection for pages $B8 - $BF
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cmp #%00000001 ; exactly system global page is protected
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bne basic
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; No BASIC.SYSTEM so quit to ProDOS dispatcher instead
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lda #<quit
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ldx #>quit
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sta done
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stx done+1
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; No BASIC.SYSTEM so use addr of ProDOS system global page
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lda #<$BF00
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ldx #>$BF00
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bne :+ ; Branch always
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; Get highest available mem addr from BASIC interpreter
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basic: lda HIMEM
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ldx HIMEM+1
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; Setup the C stack
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: sta sp
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stx sp+1
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; Check for interruptors
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lda #<__INTERRUPTOR_COUNT__
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beq :+
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; Check for ProDOS
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cpy #$4C ; Is MLI present? (JMP opcode)
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bne prterr
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; Allocate interrupt vector table entry
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jsr $BF00 ; MLI call entry point
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.byte $40 ; Alloc interrupt
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.addr i_param
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bcs prterr
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; Enable interrupts as old ProDOS versions (i.e. 1.1.1)
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; jump to SYS and BIN programs with interrupts disabled
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cli
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; Call module constructors
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: jsr initlib
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; Switch in LC bank 2 for R/O
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bit $C080
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; Push arguments and call main()
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jmp callmain
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; Print error message and return
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prterr: ldx #msglen-1
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: lda errmsg,x
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jsr $FDED ; COUT
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dex
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bpl :-
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rts
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errmsg: .ifdef __APPLE2ENH__
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.byte $8D, 't'|$80, 'p'|$80, 'u'|$80, 'r'|$80, 'r'|$80
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.byte 'e'|$80, 't'|$80, 'n'|$80, 'i'|$80, ' '|$80, 'c'|$80
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.byte 'o'|$80, 'l'|$80, 'l'|$80, 'a'|$80, ' '|$80, 'o'|$80
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.byte 't'|$80, ' '|$80, 'd'|$80, 'e'|$80, 'l'|$80, 'i'|$80
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.byte 'a'|$80, 'F'|$80, $8D
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.else
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.byte $8D, 'T'|$80, 'P'|$80, 'U'|$80, 'R'|$80, 'R'|$80
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.byte 'E'|$80, 'T'|$80, 'N'|$80, 'I'|$80, ' '|$80, 'C'|$80
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.byte 'O'|$80, 'L'|$80, 'L'|$80, 'A'|$80, ' '|$80, 'O'|$80
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.byte 'T'|$80, ' '|$80, 'D'|$80, 'E'|$80, 'L'|$80, 'I'|$80
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.byte 'A'|$80, 'F'|$80, $8D
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.endif
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msglen = * - errmsg
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; ------------------------------------------------------------------------
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.segment "LOWCODE"
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; ProDOS TechRefMan, chapter 6.2:
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; "Each installed routine must begin with a CLD instruction."
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intptr: cld
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; Call interruptors and check for success
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jsr callirq
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bcc :+
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; ProDOS TechRefMan, chapter 6.2:
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; "When the routine that can process the interrupt is called, it
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; should ... return (via an RTS) with the carry flag clear."
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clc
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rts
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; ProDOS TechRefMan, chapter 6.2:
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; "When a routine that cannot process the interrupt is called,
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; it should return (via an RTS) with the cary flag set ..."
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: sec
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rts
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; Setup RESET vector
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reset: stx SOFTEV
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sta SOFTEV+1
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eor #$A5
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sta PWREDUP
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return: rts
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; Quit to ProDOS dispatcher
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quit: jsr $BF00 ; MLI call entry point
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.byte $65 ; Quit
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.word q_param
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; ------------------------------------------------------------------------
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.rodata
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; MLI parameter list for quit
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q_param:.byte $04 ; param_count
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.byte $00 ; quit_type
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.word $0000 ; reserved
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.byte $00 ; reserved
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.word $0000 ; reserved
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; ------------------------------------------------------------------------
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.data
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; MLI parameter list for (de)alloc interrupt
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i_param:.byte $02 ; param_count
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int_num:.byte $00 ; int_num
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.addr intptr ; int_code
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; Location to jump to when we're done
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done: .addr DOSWARM
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; ------------------------------------------------------------------------
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.segment "ZPSAVE"
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zpsave: .res zpspace
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; ------------------------------------------------------------------------
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.bss
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rvsave: .res 3
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