[Freedos-devel] Kernel bug fixes need backport from dosemu2 fdpp

[Eric A. <e....@jp...>]

Hi kernel readers :-)

Looking at the development of dosemu2, I find that the
many changes there have moved away from freedos SO far
that backporting became hard, without me ever noticing.

There was the announcement of fdpp in 9/2018, one year
after development started, which morphs the kernel into
a Linux lib for dosemu2: https://github.com/stsp/fdpp
(excuse the extreme simplification of my description)

But there apparently never was a discussion about the
improvements in fdpp here, very few people at dosemu2
were in the mood to backport things, possibly inspired
by the lack of bugzilla readers here and the very few
original FreeDOS kernel people who took the effort to
cherry pick patches apparently have not shared their
capacity bottlenecks here. E.g. Andrew Bird has sent

https://github.com/PerditionC/fdkernel and
https://github.com/FDOS/kernel some patches and
Jeremy has started some cherry picking himself?

So what have we missed during all that time, 2.5 years?

- fdpp solves obscure MCB / UMB related problems which
  made FreeDOS unable to use UMB at a000:0 including
  stack overflows and reboot troubles?

- dosemu2 needs some FreeDOS-only "boot work-around" if
  hdiskboot -1, hdisks >0 and hdisk 0 is not bootable...?
  (probably to help us to boot from D: drive or similar)

- some boot changes (not sure whether dosemu2 specific) on
https://github.com/dosemu2/fdpp/commit/10507295bdea1dee3109ed115dc0dc38f98d2565#commitcomment-35887845

- FreedOS 1.2 and older has no int 2f.121f, just 2f.1217,
  but that might have been fixed back in FreeDOS recently?

- many games work better with fdpp than with FreeDOS, says
  https://github.com/dosemu2/fdpp/releases/tag/beta-9
  (Test Drive 2, Tetris Classic, Elite Frontier, Empire
  Soccer, Virtual Chess, Alone in the Dark, Alpha Waves)

- however, for example int 21.71a6 in fdpp may only be used
  in conjunction with dosemu2, according to the same site??

- fdpp fixes something related to Volkov Commander:
  https://github.com/dosemu2/fdpp/releases/tag/rc-1
  This also mentions 2 of the above games "resize PSP to 0
  and then terminate it" which apparently MS DOS accepts

- probably a lot more

Note that fdpp development seems much faster than freedos
kernel devel in part because dosemu2 disciples love their
toolchain, but dispise the tools available for real DOS?

Please, it is nice to have a few very active experts in a
few DOS related projects, but why do I have to feel like
an eavesdropper when figuring out which bugs get fixed and
which features get added? It looks a lot like many of those
probable improvements never made it to FreeDOS kernel sys
because people fail to talk about them across projects.

So please talk about those things on freedos-kernel!

If you know about a bug in FreeDOS, talk about it.

If you know about a fix in fdpp and lack the time to
backport it to FreeDOS, at least mention it here.

If you know about compatibility issues, do not just drop
from this list and install fdpp or MS DOS. Talk about it!

For those who have not experienced dosemu2 yet: Note that
it has less magic guest drivers, so you WILL have to LOAD
them in your config sys. Read their pre-installed config.

Dosemu2 is a QUICKLY moving target and following their
github feels like spying on a private chat, but most of
the time the improvements outnumber the regressions and
it work much better than the stalled classic dosemu :-)

I hope there are still some people HERE who are keen on
kernel improvements. Maybe we can wake up and at least
find out how FreeDOS 1.3 (and up) kernels COULD improve.

Thank you! Regards, Eric

PS: Excuse the cross-post CC to freedos-devel. It is for
the case that there are not enough kernel readers left.