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 ; This must be the *first* file on the linker command line
11 .export __STARTUP__ : absolute = 1 ; Mark as startup
13 .import initlib, donelib
14 .import push0, _main, zerobss
16 .import tmp1,tmp2,tmp3
19 .import __RAM_START__, __RAM_SIZE__
20 .import __ROM0_START__, __ROM0_SIZE__
21 .import __ROM_START__, __ROM_SIZE__
22 .import __STARTUP_LOAD__,__STARTUP_RUN__, __STARTUP_SIZE__
23 .import __CODE_LOAD__,__CODE_RUN__, __CODE_SIZE__
24 .import __RODATA_LOAD__,__RODATA_RUN__, __RODATA_SIZE__
25 .import __DATA_LOAD__,__DATA_RUN__, __DATA_SIZE__
33 ; ------------------------------------------------------------------------
34 ; Place the startup code in a special segment.
40 ; setup the CPU and System-IRQ
46 csh ; set high speed CPU mode
51 ; Setup stack and memory mapping
52 ldx #$FF ; Stack top ($21FF)
55 ; at startup all MPRs are set to 0, so init them
57 tam #%00000001 ; 0000-1FFF = Hardware page
59 tam #%00000010 ; 2000-3FFF = Work RAM
61 ;tam #%00000100 ; 4000-5FFF = Save RAM
63 ;tam #%00001000 ; 6000-7FFF Page 2
65 ;tam #%00010000 ; 8000-9FFF Page 3
67 ;tam #%00100000 ; A000-BFFF Page 4
69 ;tam #%01000000 ; C000-DFFF Page 5
71 ;tam #%10000000 ; e000-fFFF hucard/syscard bank 0
73 ; Clear work RAM (2000-3FFF)
75 tii $2000, $2001, $1FFF
78 stz TIMER_COUNT ; Timer off
80 sta IRQ_MASK ; Interrupts off
81 stz IRQ_STATUS ; Acknowledge timer
83 ;; FIXME; i dont know why the heck this one doesnt work when called from a constructor :/
87 ; Turn on background and VD interrupt/IRQ1
89 sta IRQ_MASK ; IRQ1=on
94 ; Copy the .data segment to RAM
104 ldx #>(__DATA_SIZE__)
106 beq @s1 ; no more full pages
122 ; copy remaining bytes
130 cpy #<(__DATA_SIZE__)
134 lda #<(__RAM_START__+__RAM_SIZE__)
136 lda #>(__RAM_START__+__RAM_SIZE__)
139 ; Call module constructors
142 cli ; allow IRQ only after constructors have run
144 ; Pass an empty command line
148 ldy #4 ; Argument size
149 jsr _main ; call the users code
151 ; Call module destructors. This is also the _exit entry.
153 jsr donelib ; Run module destructors
155 ; reset the PCEngine (start over)
158 ; ------------------------------------------------------------------------
159 ; System V-Blank Interupt
160 ; FIXME: hooks should be provided so the user can abuse the IRQ
161 ; ------------------------------------------------------------------------
177 ; Acknowlege interrupt
196 ; ------------------------------------------------------------------------
198 ; ------------------------------------------------------------------------
201 .word _irq2 ; $fff6 IRQ2 (External IRQ, BRK)
202 .word _irq1 ; $fff8 IRQ1 (VDC)
203 .word _timer ; $fffa Timer
204 .word _nmi ; $fffc NMI
205 .word start ; $fffe reset