asiekierka
commented
5 months ago Works fine with -Os, and also appears to have worked fine in an earlier version of the compiler (though I'm not sure from when exactly...).
Closed bcampbell closed 5 months ago
asiekierka
commented
5 months ago Works fine with -Os, and also appears to have worked fine in an earlier version of the compiler (though I'm not sure from when exactly...).
mysterymath
commented
5 months ago I did some preliminary digging, and something somewhere is issuing a jump to 0x0000. There doesn't seem to be anything obviously amiss in the generated assembly, nor an indirect jump or anything that could get clobbered. I'd suspect some kind of hinky interaction between the SDK and the neo6502 libraries it calls, but I don't really know enough about the debugging features available on the neo6502 emulator (or the target) to do much very effective further digging.
If someone can trace down where in the assembly this example is going awry, I can probably take care of the compiler side of things.
bcampbell
commented
5 months ago Been tinkering. Hope there's something useful here. I hacked the emulator to add a "trace" mode to dump out every instruction executed. (I also added a printf to say when system calls are invoked, but that's not part of the PR)
Here's my revised test program:
// To compile and run on the neo6502 emulator:
// $ mos-neo6502-clang crashy.c -o crashy
// $ neo crashy@0x0800 exec trace
#include <neo/api.h>
int main(int argc, char* argv[])
{
neo_graphics_set_defaults(0xff, 0x00, 1, 0, 0);
neo_graphics_set_color(1);
/* but this crashes the 6502 :-( */
for (uint8_t i=0; i<4; ++i) {
neo_graphics_draw_line(0+i,0,300+i,190);
}
return 0;
}Here's the output I get.
I can see it perform the first two system calls, but it dies before the first neo_graphics_draw_line() call gets as far as invoking the system call.
$ neo crashy@0x0800 exec trace
Load crashy to 800
Warm boot $806
[Beeper] frequency: 44100
[Beeper] format: AUDIO_S16
[Beeper] channels: 1
[Beeper] samples: 512
[Beeper] padding: 0
[Beeper] size: 1024
0806 85 01 sta 01
0808 20 0f 08 jsr 080f
080f 48 pha
0810 18 clc
0811 a5 00 lda 00
0813 69 f9 adc #f9
0815 85 00 sta 00
0817 a5 01 lda 01
0819 69 ff adc #ff
081b 85 01 sta 01
081d 68 pla
081e 85 06 sta 06
0820 18 clc
0821 a5 00 lda 00
0823 69 05 adc #05
0825 85 04 sta 04
0827 a5 01 lda 01
0829 69 00 adc #00
082b 85 05 sta 05
082d a9 00 lda #00
082f 92 04 sta (04)
0831 a0 01 ldy #01
0833 91 04 sta (04),y
0835 18 clc
0836 a5 00 lda 00
0838 69 03 adc #03
083a 85 04 sta 04
083c a5 01 lda 01
083e 69 00 adc #00
0840 85 05 sta 05
0842 a5 06 lda 06
0844 92 04 sta (04)
0846 8a txa
0847 91 04 sta (04),y
0849 a5 02 lda 02
084b a6 03 ldx 03
084d 18 clc
084e 48 pha
084f a5 00 lda 00
0851 69 01 adc #01
0853 85 02 sta 02
0855 a5 01 lda 01
0857 69 00 adc #00
0859 85 03 sta 03
085b 68 pla
085c 92 02 sta (02)
085e 8a txa
085f 91 02 sta (02),y
0861 20 e0 08 jsr 08e0
08e0 a2 ff ldx #ff
08e2 8e 04 ff stx ff04
08e5 9c 05 ff stz ff05
08e8 a2 01 ldx #01
08ea 8e 06 ff stx ff06
08ed 9c 07 ff stz ff07
08f0 9c 08 ff stz ff08
08f3 20 f7 ff jsr fff7
fff7 4c 18 fc jmp fc18
fc18 20 81 fc jsr fc81
fc81 48 pha
fc82 ad 00 ff lda ff00
fc85 d0 fb bne fc82
fc87 68 pla
fc88 60 rts
fc1b 8d 38 fc sta fc38
fc1e 68 pla
fc1f 8d 45 fc sta fc45
fc22 68 pla
fc23 8d 46 fc sta fc46
fc26 20 3c fc jsr fc3c
fc3c ee 45 fc inc fc45
fc3f d0 03 bne fc44
fc44 ad f6 08 lda 08f6
fc47 60 rts
fc29 48 pha
fc2a 20 3c fc jsr fc3c
fc3c ee 45 fc inc fc45
fc3f d0 03 bne fc44
fc44 ad f7 08 lda 08f7
fc47 60 rts
fc2d 8d 01 ff sta ff01
fc30 68 pla
fc31 8d 00 ff sta ff00
***** DSPHander cmd=5 fn=1 // syscall invoked to the rp2040 mcu: "graphics / set defaults"
fc34 20 3c fc jsr fc3c
fc3c ee 45 fc inc fc45
fc3f d0 03 bne fc44
fc44 ad f8 08 lda 08f8
fc47 60 rts
fc37 a9 00 lda #00
fc39 6c 45 fc jmp (fc45)
08f8 60 rts
0864 20 1d 09 jsr 091d
091d a2 01 ldx #01
091f 8e 04 ff stx ff04
0922 20 f7 ff jsr fff7
fff7 4c 18 fc jmp fc18
fc18 20 81 fc jsr fc81
fc81 48 pha
fc82 ad 00 ff lda ff00
fc85 d0 fb bne fc82
fc87 68 pla
fc88 60 rts
fc1b 8d 38 fc sta fc38
fc1e 68 pla
fc1f 8d 45 fc sta fc45
fc22 68 pla
fc23 8d 46 fc sta fc46
fc26 20 3c fc jsr fc3c
fc3c ee 45 fc inc fc45
fc3f d0 03 bne fc44
fc44 ad 25 09 lda 0925
fc47 60 rts
fc29 48 pha
fc2a 20 3c fc jsr fc3c
fc3c ee 45 fc inc fc45
fc3f d0 03 bne fc44
fc44 ad 26 09 lda 0926
fc47 60 rts
fc2d 8d 01 ff sta ff01
fc30 68 pla
fc31 8d 00 ff sta ff00
***** DSPHander cmd=5 fn=64 // syscall invoked to the rp2040 mcu: "graphics / set color"
fc34 20 3c fc jsr fc3c
fc3c ee 45 fc inc fc45
fc3f d0 03 bne fc44
fc44 ad 27 09 lda 0927
fc47 60 rts
fc37 a9 00 lda #00
fc39 6c 45 fc jmp (fc45)
0927 60 rts
0867 18 clc
0868 a6 00 ldx 00
086a 86 02 stx 02
086c a6 01 ldx 01
086e 86 03 stx 03
0870 a9 00 lda #00
0872 92 02 sta (02)
0874 18 clc
0875 a6 00 ldx 00
0877 86 02 stx 02
0879 a6 01 ldx 01
087b 86 03 stx 03
087d b2 02 lda (02)
087f 85 02 sta 02
0881 a9 00 lda #00
0883 a6 02 ldx 02
0885 e0 04 cpx #04
0887 e9 00 sbc #00
0889 70 02 bvs 088d
088b 80 04 bra 0891
0891 80 00 bra 0893
0893 aa tax
0894 10 32 bpl 08c8
0896 80 00 bra 0898
0898 18 clc
0899 a6 00 ldx 00
089b 86 02 stx 02
089d a6 01 ldx 01
089f 86 03 stx 03
08a1 b2 02 lda (02)
08a3 a8 tay
08a4 b2 02 lda (02)
08a6 18 clc
08a7 69 2c adc #2c
08a9 85 02 sta 02
08ab a9 00 lda #00
08ad 69 01 adc #01
08af 85 03 sta 03
08b1 a2 00 ldx #00
08b3 98 tya
08b4 20 f9 08 jsr 08f9
08f9 a4 02 ldy 02
08fb 8d 04 ff sta ff04
08fe 8e 05 ff stx ff05
0901 9c 06 ff stz ff06
0904 9c 07 ff stz ff07
0907 8c 08 ff sty ff08
090a a6 03 ldx 03
090c 8e 09 ff stx ff09
090f a2 be ldx #be
0911 8e 0a ff stx ff0a
0914 9c 0b ff stz ff0b
0917 20 f7 ff jsr fff7
fff7 4c 18 00 jmp 0018
0018 00 brkfff7 4c 18 00 jmp 0018That smells like a bug in the Neo6502 kernel, not in LLVM-MOS.
bcampbell
commented
5 months ago fff7 4c 18 00 jmp 0018That smells like a bug in the Neo6502 kernel, not in LLVM-MOS.
Oh yes! I didn't even notice that!
fff7 is KSendMessage(), and earlier calls have it down as:
fff7 4c 18 fc jmp fc18Hmm. I wonder if the real hardware allows writes to the kernal code? The emulator does. I added some extra printfs to dump out memory locations 2, 3 and $fff7-$fff9 and reran the same program, and I can see it blatting over $fff9.
$ neo crashy@0x0800 exec trace
Load crashy to 800
Warm boot $806
[Beeper] frequency: 44100
[Beeper] format: AUDIO_S16
[Beeper] channels: 1
[Beeper] samples: 512
[Beeper] padding: 0
[Beeper] size: 1024
0806 85 01 sta 01 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0808 20 0f 08 jsr 080f (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
080f 48 pha (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0810 18 clc (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0811 a5 00 lda 00 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0813 69 f9 adc #f9 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0815 85 00 sta 00 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0817 a5 01 lda 01 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0819 69 ff adc #ff (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
081b 85 01 sta 01 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
081d 68 pla (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
081e 85 06 sta 06 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0820 18 clc (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0821 a5 00 lda 00 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0823 69 05 adc #05 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0825 85 04 sta 04 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0827 a5 01 lda 01 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0829 69 00 adc #00 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
082b 85 05 sta 05 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
082d a9 00 lda #00 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
082f 92 04 sta (04) (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0831 a0 01 ldy #01 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0833 91 04 sta (04),y (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0835 18 clc (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0836 a5 00 lda 00 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0838 69 03 adc #03 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
083a 85 04 sta 04 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
083c a5 01 lda 01 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
083e 69 00 adc #00 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0840 85 05 sta 05 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0842 a5 06 lda 06 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0844 92 04 sta (04) (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0846 8a txa (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0847 91 04 sta (04),y (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0849 a5 02 lda 02 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
084b a6 03 ldx 03 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
084d 18 clc (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
084e 48 pha (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
084f a5 00 lda 00 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0851 69 01 adc #01 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0853 85 02 sta 02 (2=00 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0855 a5 01 lda 01 (2=fa 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0857 69 00 adc #00 (2=fa 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
0859 85 03 sta 03 (2=fa 3=00 $FFF7=4c $FFF8=18 $FFF9=fc)
085b 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
085c 92 02 sta (02) (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
085e 8a txa (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
085f 91 02 sta (02),y (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
0861 20 e0 08 jsr 08e0 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08e0 a2 ff ldx #ff (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08e2 8e 04 ff stx ff04 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08e5 9c 05 ff stz ff05 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08e8 a2 01 ldx #01 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08ea 8e 06 ff stx ff06 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08ed 9c 07 ff stz ff07 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08f0 9c 08 ff stz ff08 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08f3 20 f7 ff jsr fff7 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fff7 4c 18 fc jmp fc18 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc18 20 81 fc jsr fc81 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc81 48 pha (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc82 ad 00 ff lda ff00 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc85 d0 fb bne fc82 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc87 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc88 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc1b 8d 38 fc sta fc38 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc1e 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc1f 8d 45 fc sta fc45 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc22 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc23 8d 46 fc sta fc46 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc26 20 3c fc jsr fc3c (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3c ee 45 fc inc fc45 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3f d0 03 bne fc44 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc44 ad f6 08 lda 08f6 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc47 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc29 48 pha (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc2a 20 3c fc jsr fc3c (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3c ee 45 fc inc fc45 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3f d0 03 bne fc44 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc44 ad f7 08 lda 08f7 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc47 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc2d 8d 01 ff sta ff01 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc30 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc31 8d 00 ff sta ff00 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
***** DSPHander cmd=5 fn=1
fc34 20 3c fc jsr fc3c (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3c ee 45 fc inc fc45 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3f d0 03 bne fc44 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc44 ad f8 08 lda 08f8 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc47 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc37 a9 00 lda #00 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc39 6c 45 fc jmp (fc45) (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
08f8 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
0864 20 1d 09 jsr 091d (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
091d a2 01 ldx #01 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
091f 8e 04 ff stx ff04 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
0922 20 f7 ff jsr fff7 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fff7 4c 18 fc jmp fc18 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc18 20 81 fc jsr fc81 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc81 48 pha (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc82 ad 00 ff lda ff00 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc85 d0 fb bne fc82 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc87 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc88 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc1b 8d 38 fc sta fc38 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc1e 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc1f 8d 45 fc sta fc45 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc22 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc23 8d 46 fc sta fc46 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc26 20 3c fc jsr fc3c (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3c ee 45 fc inc fc45 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3f d0 03 bne fc44 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc44 ad 25 09 lda 0925 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc47 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc29 48 pha (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc2a 20 3c fc jsr fc3c (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3c ee 45 fc inc fc45 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3f d0 03 bne fc44 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc44 ad 26 09 lda 0926 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc47 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc2d 8d 01 ff sta ff01 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc30 68 pla (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc31 8d 00 ff sta ff00 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
***** DSPHander cmd=5 fn=64
fc34 20 3c fc jsr fc3c (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3c ee 45 fc inc fc45 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc3f d0 03 bne fc44 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc44 ad 27 09 lda 0927 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc47 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc37 a9 00 lda #00 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
fc39 6c 45 fc jmp (fc45) (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
0927 60 rts (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
0867 18 clc (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
0868 a6 00 ldx 00 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
086a 86 02 stx 02 (2=fa 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
086c a6 01 ldx 01 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
086e 86 03 stx 03 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
0870 a9 00 lda #00 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=fc)
0872 92 02 sta (02) (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=fc) // BLATBLATBLATBLATBLAT!!!!!
0874 18 clc (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0875 a6 00 ldx 00 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0877 86 02 stx 02 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0879 a6 01 ldx 01 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
087b 86 03 stx 03 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
087d b2 02 lda (02) (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
087f 85 02 sta 02 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0881 a9 00 lda #00 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0883 a6 02 ldx 02 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0885 e0 04 cpx #04 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0887 e9 00 sbc #00 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0889 70 02 bvs 088d (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
088b 80 04 bra 0891 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0891 80 00 bra 0893 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0893 aa tax (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0894 10 32 bpl 08c8 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0896 80 00 bra 0898 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0898 18 clc (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
0899 a6 00 ldx 00 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
089b 86 02 stx 02 (2=00 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
089d a6 01 ldx 01 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
089f 86 03 stx 03 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08a1 b2 02 lda (02) (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08a3 a8 tay (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08a4 b2 02 lda (02) (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08a6 18 clc (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08a7 69 2c adc #2c (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08a9 85 02 sta 02 (2=f9 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08ab a9 00 lda #00 (2=2c 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08ad 69 01 adc #01 (2=2c 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08af 85 03 sta 03 (2=2c 3=ff $FFF7=4c $FFF8=18 $FFF9=00)
08b1 a2 00 ldx #00 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
08b3 98 tya (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
08b4 20 f9 08 jsr 08f9 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
08f9 a4 02 ldy 02 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
08fb 8d 04 ff sta ff04 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
08fe 8e 05 ff stx ff05 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
0901 9c 06 ff stz ff06 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
0904 9c 07 ff stz ff07 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
0907 8c 08 ff sty ff08 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
090a a6 03 ldx 03 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
090c 8e 09 ff stx ff09 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
090f a2 be ldx #be (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
0911 8e 0a ff stx ff0a (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
0914 9c 0b ff stz ff0b (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
0917 20 f7 ff jsr fff7 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
fff7 4c 18 00 jmp 0018 (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)
0018 00 brk (2=2c 3=01 $FFF7=4c $FFF8=18 $FFF9=00)Interesting, the "BLAT" is a write to the current top of the C stack (the stack pointer is stored in zero page locations 0 and 1). Somehow the stack pointer ended up pointing at 0xfff9, which isn't correct. It does look like it's being initialized to 0xf600 at program start, which seems fine.
mysterymath
commented
5 months ago Actually, not it's not, it says it's warm booting to 0x806, not 0x800. That would cut off the start of the stack pointer initialization, which would lead to it pointing somewhere invalid. I think that's the root cause here.
mysterymath
commented
5 months ago From the emulator docs, it looks like it does default to 0x806 as the start address. We'd need to make that the case in our linker scripts if that's a hard constrain.
@asiekierka , do you know anything about how programs are expected to be loaded on the neo6502? Is this an emulator-only thing?
asiekierka
commented
5 months ago I followed their cc65 example, which uses test -f hello.neo && ../../bin/neo hello.neo@800 cold to launch the generated executable and doesn't make any concessions for warm boots.
mysterymath
commented
5 months ago Alright, in that case I'm going to close this one as Working As Intended; the crasher example does work under that command line.
bcampbell
commented
5 months ago Oops, sorry for the false alarm! Thanks so much for tracking down the issue!
I can get a simple helloworld going OK on the neo6502 target, but I hit problems as soon as I start using any variables. Here's program to demonstrate the issue:
It works fine until I try using the loop, and then the emulated 6502 just chokes and dies on it.
I feel like I've had this problem on other targets. I'm pretty sure I hit something similar on the PCEngine target, but at the time I just assumed I'd screwed up memory banking macros... And when I was playing around with Fenix256k support, I think I saw something like this too. In that case it was just missing out one of the crt init routines in the CMakefile or linker scripts (e.g. the one that clears bss memory? Or zeropage data?). Sorry, that's a bit woolly and non-specific. But I do think it might be a wider problem, and my gut feeling is that it'll turn out to be something quite simple...
(For comparison, I've found the c64 and cx16 targets to be rock-solid - I've given them both a good workout with projects well over 1000 LoC).