Trying to hack up a change to fdpp kernel, but getting a crash.

[andrewbird]

Firstly I'm still without broadband here, so I'm having to retype everything on mobile. I have a structure that I'd like to be able to set es:Di to. Simplified the code looks something like this:

Struct xgetxxx s;
Struct xgetxxx FAR *p;

p=MK_FAR(s);

regs.es = FP_SEG(p);
regs.di = FP_OFF(p);

But I get a crash, fdpp logging in dosemu mentions something about rtti symbol not found for class. What am I doing wrong?

Thanks.

[stsp]

Never seen any rtti-mentioning errors,
so no idea really. This may be a bad build.
But make sure regs has the same
life-range as s and use MK_xxx_OBJ()
macros:
https://github.com/dosemu2/fdpp/blob/master/kernel/initdisk.c#L728-L733

[andrewbird]

Unfortunately switching to the obj macros didnt help. I may have messed up the parameter passing to the function, perhaps this is corrupting something. But thanks anyway!

[andrewbird]

Actually using the MK_xxx_OBJ() did fix this problem, only I had something else wrong afterwards that also caused a crash and I didn't notice the difference.

[andrewbird]

Can you remind me what I need to do to debug FDPP with gdb, please? I know you've told me in the past, but I've just tried searching old PRs and issues and can't find it. That's a lesson learnt for me, and so this time I'll add it to dosemu's wiki!

[andrewbird]

Thanks, I now see your commit fae984d. I see it looks for string 'debug' in the buildtype, so I presume I use 'debug' instead of 'release' in the line above?

[stsp]

No, as it seems to be a default anyway.
Only release changes settings (in a way
you don't need).

[andrewbird]

So I should omit the --buildtype=release altogether?

[stsp]

Seems so.

[andrewbird]

Cool, thanks!