2 ; Startup code for cc65 (PCEngine version)
4 ; by Groepaz/Hitmen <groepaz@gmx.net>,
5 ; based on code by Ullrich von Bassewitz <uz@cc65.org>.
7 ; 2018-02-11, Greg King
11 .export __STARTUP__ : absolute = 1 ; Mark as startup
13 .import initlib, donelib
19 .import __DATA_LOAD__, __DATA_RUN__, __DATA_SIZE__
20 .import __BSS_RUN__, __BSS_SIZE__
21 .import __MAIN_START__, __MAIN_SIZE__, __STACKSIZE__
28 ; ------------------------------------------------------------------------
29 ; Place the startup code in a special segment.
36 csh ; Set high-speed CPU mode
39 ; Set up stack and memory mapping.
40 ldx #$FF ; Stack top ($21FF)
43 ; At power-on, most MPRs have random values; so, initiate them.
45 tam #%00000001 ; $0000-$1FFF = Hardware bank
47 tam #%00000010 ; $2000-$3FFF = Work RAM
49 ;tam #%00000100 ; $4000-$47FF = 2K Battery-backed RAM
51 ;tam #%00001000 ; $6000-$7FFF
57 tam #%00010000 ; $8000-$9FFF = ROM bank 1 (32K block of ROM)
59 tam #%00100000 ; $A000-$BFFF = ROM bank 2
61 @L1: tam #%01000000 ; $C000-$DFFF = ROM bank 3 (32K) or 1 (16K)
62 ;lda #$00 ; (The reset default)
63 ;tam #%10000000 ; $E000-$FFFF Hucard/Syscard bank 0
66 stz TIMER_CTRL ; Timer off
68 sta IRQ_MASK ; Interrupts off
69 stz IRQ_STATUS ; Acknowledge timer
71 ; FIXME; I don't know why the heck this one doesn't work when called from a constructor. :/
75 ; Turn on background and VD interrupt/IRQ1
77 sta IRQ_MASK ; IRQ1 = on
79 ; Copy the .data segment to RAM
80 tii __DATA_LOAD__, __DATA_RUN__, __DATA_SIZE__
82 ; Clear the .bss segment
84 tii __BSS_RUN__, __BSS_RUN__ + 1, __BSS_SIZE__ - 1
87 lda #<(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)
88 ldx #>(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)
92 ; Call module constructors
95 cli ; allow IRQ only after constructors have run
97 ; Pass an empty command line
101 ldy #4 ; Argument size
102 jsr _main ; Call the user's code
104 ; Call module destructors. This is also the _exit entry.
105 _exit: jsr donelib ; Run module destructors
107 ; reset the PCEngine (start over)
116 ; ------------------------------------------------------------------------
118 ; ------------------------------------------------------------------------
121 .word IRQStub ; $FFF6 IRQ2 (External IRQ, BRK)
122 .word IRQStub ; $FFF8 IRQ1 (VDC)
123 .word IRQStub ; $FFFA Timer
124 .word _nmi ; $FFFC NMI
125 .word start ; $FFFE reset