Re: [Qemu-ppc] [OpenBIOS] MorphOS 4.x on QEMU

[BALATON Zoltan]

On Sun, 2 Mar 2014, Mark Cave-Ayland wrote:
> Now the fact that nextprop returns -1 indicates that the following check has 
> failed:
>
>  \ verify that prev exists (overkill...)
>  dup if
>    2dup r@ get-package-property if
>      r> 2drop 2drop -1 exit
>    else
>      2drop
>    then
>  then
>
> This means that the client requested the next property after "name" but 
> OpenBIOS's get-package-property couldn't find "name" and so returns -1 back 
> to the caller as shown in your trace.

If I remove this check it returns 0 and an empty string. With debug 
nextprop (and the above check removed + Olivier's patch) I get the 
following:

> > finddevice("/cpus") = 0xfff4bba8
> > child(0xfff4bba8) = 0xfff51908
> > nextprop(0xfff51908, "", 0x07de7e30) =
: nextprop  ( 7de7e30 7de7e30 fff51908 )
fff4a06c: >r
R: ( fff49af0 fff49bec fff383a4 fff4aa8c fff3dba4 0 fff3db54 fffb4214 fff4cb08 0
 3 0 fff35164 fffb4214 fff38584 7c58522 100 0 15 16 fff38500 fff37dfc fffb4214 f
ff49224 fff448c0 fffb4214 fffb4214 fff4a8b0 fff4a7ac 0 4 c fff35164 fffb4214 )
 ( 7de7e30 7de7e30 )
fff4a070: dup  ( 7de7e30 7de7e30 7de7e30 )
fff4a074: 0=  ( 7de7e30 7de7e30 0 )
fff4a078: do?branch  ( 7de7e30 7de7e30 )
fff4a08c: dup  ( 7de7e30 7de7e30 7de7e30 )
fff4a090: cstrlen  ( 7de7e30 7de7e30 0 )
fff4a094: 0  ( 7de7e30 7de7e30 0 0 )
fff4a098: 3  ( 7de7e30 7de7e30 0 0 3 )
fff4a09c: pick  ( 7de7e30 7de7e30 0 0 7de7e30 )
fff4a0a0: c!  ( 7de7e30 7de7e30 0 )
fff4a0a4: r>  ( 7de7e30 7de7e30 0 fff51908 )
fff4a0a8: next-property-std  ( 7de7e30 fff5197c 4 ffffffff )
fff4a0ac: do?branch  ( 7de7e30 fff5197c 4 )
fff4a0b4: dup  ( 7de7e30 fff5197c 4 4 )
fff4a0b8: 1+  ( 7de7e30 fff5197c 4 5 )
fff4a0bc: -rot  ( 7de7e30 5 fff5197c 4 )
fff4a0c0: ci-strcpy  ( 4 )
fff4a0c4: drop  ( Empty )
fff4a0c8: 1  ( 1 )
fff4a0cc: dobranch  ( 1 )
fff4a0dc: (semis)
[ Finished nextprop ] 1
> > 0x07de7e30  6e 61 6d 65 00 00 00 00 00 00 00 00 00 00 00 00  name............
> > 0x07de7e40  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
> > getprop(0xfff51908, "name", 0x07de7df0, 64) = 11
> > 0x07de7df0  50 6f 77 65 72 50 43 2c 47 34 00 __ __ __ __ __  PowerPC,G4.
> > nextprop(0xfff51908, "name", 0x07de7e30) =
: nextprop  ( 7de7e30 7de7e30 fff51908 )
fff4a06c: >r
R: ( fff49af0 fff49bec fff383a4 fff4aa8c fff3dba4 0 fff3db54 fffb4214 fff4cb08 0
 3 0 fff35164 fffb4214 fff38584 7c58522 100 0 15 16 fff38500 fff37dfc fffb4214 f
ff49224 fff448c0 fffb4214 fffb4214 fff4a8b0 fff4a7ac 0 4 c fff35164 fffb4214 )
 ( 7de7e30 7de7e30 )
fff4a070: dup  ( 7de7e30 7de7e30 7de7e30 )
fff4a074: 0=  ( 7de7e30 7de7e30 0 )
fff4a078: do?branch  ( 7de7e30 7de7e30 )
fff4a08c: dup  ( 7de7e30 7de7e30 7de7e30 )
fff4a090: cstrlen  ( 7de7e30 7de7e30 4 )
fff4a094: 0  ( 7de7e30 7de7e30 4 0 )
fff4a098: 3  ( 7de7e30 7de7e30 4 0 3 )
fff4a09c: pick  ( 7de7e30 7de7e30 4 0 7de7e30 )
fff4a0a0: c!  ( 7de7e30 7de7e30 4 )
fff4a0a4: r>  ( 7de7e30 7de7e30 4 fff51908 )
fff4a0a8: next-property-std  ( 7de7e30 0 )
fff4a0ac: do?branch  ( 7de7e30 )
fff4a0d4: drop  ( Empty )
fff4a0d8: 0  ( 0 )
fff4a0dc: (semis)
[ Finished nextprop ] 0
> > 0x07de7e30  00 61 6d 65 00 00 00 00 00 00 00 00 00 00 00 00  .ame............
> > 0x07de7e40  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
> > child(0xfff51908) = 0x00000000

> You should find that OpenBIOS boots your image and then breaks on nextprop, 
> allowing you to step through the function examining the stack (and input 
> string) to see what is going wrong.

I hope the above make sense to you and helps finding why it does not work.

Regards,
BALATON Zoltan