Bochs/bochs/TODO

This is the "roadmap" posted in the mailing list, augmented by 
comments from the mailing list and the irc chat. 
Anybody is welcome to work on any of these issues. Some of
these items are rather simple and can be implemented by single 
individuals. Other items are quite complex and development needs 
to be coordonated. So, if you want to contribute, please drop 
us a note in the mailing list, so you can get help or exchange 
ideas.
Christophe Bothamy.

0. Donations
Source Forge recently set up a donation system for hosted projects.
Should we accept donations ? What could we do with the money ? 
- give to EFF, FSF or other 
- fund Kevin to continue the work on plex86 so we can use it
- bounties for somebody write optimized win9x/NT/XFree/linux/*BSD 
  drivers for our vga/net/ide cards
- other ?
Status in Bochs 2.3:
No decisions about this yet.

1. Speed
Speed (well lack of) is one of the biggest criticism made by users
who'd like to see Bochs run as fast as Virtual PC.
Paths we can explore to get more speed :
4.1 virtualization : plex86
4.2 dynamic translation : qemu, patch from h.johansson
4.3 optimizations of instructions path / host asm (Conn Clark has been
working on this, and an anonymous patch for win32 
http://sourceforge.net/tracker/index.php?func=detail&aid=867044&group_id=12580&atid=312580
)
Status:
Not done yet.

2. Plugin architecture
2.1 The plugin architecture can be reworked if we want to support
multiple similar devices like seral net or vga cards.
We currently have two "types" of plugins: "core" and "optional". 
Maybe we could add "classes" of plugins. The current version of 
Bochs supports the classes "display_library" and "io_device". 
New classes can be "config_interface", "net_lowlevel" and 
"sound_lowlevel"
2.2 Stanislav wrote :
Plugin architecture should be rewritten like real plugin architecture s.t.
Bochs VGA plugin for example will be real plugin. I mean that replacement 
of plugin dll in already compiled Bochs will replace Bochs VGA card and 
the new card will be detected automatically.
This will allow for example developing of plugins separately from Bochs.
2.3 Michael Brown wrote :
If the configuration interface is to be reworked, could we also make it so 
that plugins are self-contained, rather than needing to pollute config.cc 
with code for defining and parsing plugin-specific options
Status:
A little bit of the basic work is done now: The config parameter handling has
been rewritten to a parameter tree and user-defined bochsrc options are now
supported. The main plugin architecture rewrite is not done yet.

3. PCI host<->guest proxy
Being able to use a real pci device from inside Bochs would be a 
great feature of Bochs. It would ease reverse engineering of non
documented cards, or one could even use a real spare vga card.
Frank Cornellis has done a great job on this subject, and we began
integrating his changes. 
Status:
The pcidev device is present in CVS and it has been updated for the new PCI
infrastructure, but the new code is untested yet.

4. Subdirectories in iodev
The iodev directory contains the various implemented iodevice.
With the new pci devices, new harddrives and new net access methods, 
it could be interesting to add new subdirectories like :
iodev/video/... --> for standard vga and new card emulation
iodev/disks/... --> for the ata/atapi classes, hd/cd classes and host accesses
iodev/net/...   --> for ne2k and host net access
isa and pci devices would be mixed in the directories, but this should
be manageable.
Status:
Not done yet.

5 multithreading. Conn Clark wrote :
Threading might be nice too, for those of us who have SMP/SMT machines. 
I have a patch from Mathis (who hangs out on the IRC channel all the 
time) that puts the video card interface in its own thread. It has 
troubles though that I have not resolved. It may also be easier to debug 
a threaded peripheral.
I also think that it might be possible to thread a chunk of the CPU 
emulation to improve performance on a SMP/SMT machine. Specificaly 
write_virtual_dword, write_virtual_word, write_virtual_byte, etc... 
might just be able to be threaded. I think the threading overhead might 
be less than the protection and address translation code. We would have 
to try it to find out. I'm also sure there can be some nasty hurdles to 
overcome.
Status:
Third party proup started a para-Bochs project exacly to reach above goals,
some beta version is already released. 
The home page of the project: http://grid.hust.edu.cn/cluster/VirtualMachine/index.html

6. CPU
6.1 This was asked in the ml, and I believe it's a good idea to provide
a configure switch to set the cpu model, for example :
--with-cpu-386
--with-cpu-486dx
--with-cpu-pentium
--with-cpu-pentium-mmx
--with-cpu-k6-iii
--with-cpu-amd64
and so on. The main difficulty here is to set up the list of features
by cpu model. I started such a list, available at 
http://cbothamy.free.fr/projects/bochs/CPU_Features.sxc
The configure script will then set up constants on features to compile in,
ISA, FPU, MMX, 3DNOW, SSE, etc... Most of the feature flags already 
exists in config.h, so this should be easy. It would also be a good
idea to clean up the cpuid function beased on those flags.
We also have to keep in mind that some features are also enablable
by the guest os.
Please note the all features are still not supported/complete in Bochs.
6.2 Stanislav thinks that configure --with-cpu-pentium-mmx --enable-cpu-level-4 
would create lots of conflicts in the generated config.h. He suggests
that we should write an external GUI configure script that would propose 
standard or custom cpus and would detect conflicts.
Status:
Not done yet.

7. VGA
For SVGA emulation we have Bochs VBE and the Cirrus adapter. We should have
a look at the voodoo3 (specs http://v3tv.sourceforge.net/docs.php).
Status:
Not done yet.

8. Random thoughts on disk emulation improvements :
8.1 lba48 support
8.2 autodetection of disk size / geometry
8.3 uml cow disk image support
8.4 compressed disk image support
8.5 extend redolog-disk specification to add coherency check of the flat 
image file, by storing its fstat-mtime field in the redolog.
Status:
Autodetection now works for all image types created with bximage and vmware3
images. LBA48 and vmware4 disk images support was added in Bochs 2.3.5 release.
The other items are not done yet.

9. net
9.1 bootable ethernet rom ? 
see etherboot, Micheal Brown wrote :
This already works; you can build an Etherboot rom image with the pnic 
driver, specify it as an option ROM in bochsrc and it will boot.  I'm 
using this extensively at the moment in Etherboot development.
In the Etherboot project's CVS, in the contrib/bochs directory, you can
find a working bochsrc file and an up-to-date README with step-by-step 
instructions on getting this working.
Status:
The pnic device is present in CVS, but the status is unknown.

10. Bios
10.1 our bios is quite heavy on stack space (notably during int13 functions).
Some parts can be rewritten in assembler, to save stack space and 
make code smaller.
Status:
New BIOS supporting ACPI was introduced in Bochs 2.3.5 release.

10.2 add "jump table placeholder" and log missing function calls in the bios. 
Check completness with Ralf Brown interrupt list.
Status:
Not done yet.

11. LGPL VGABios
11.1 Video parameters table
There is a very nice parameter table in 3dfx banshee document 
http://www2.lm-sensors.nu/~lm78/pdfs/Banshee_2d_spec.PDF
see also http://www.xyzzy.claranet.de/dos/vgacrt.c
Status:
The new version 0.6a of the LGPL'd VGABIOS has minimal support for the video
parameter table.

12. Optimized Guest drivers still needed : VGA, IDE, NET
We have a specific VGA driver for winNT/2K, but still
lack drivers for other OSes.
Status:
Not done yet.

13. USB support
Ben Lunt has been working on USB support. The USB mouse and keypad code
is present in Bochs and almost stable. USB flash disk support has been
started and the runtime device change support should be completed.
Status:
Under construction.

14. Config file and dynamic menu
14.1 Benjamen R. Meyer wrote :
I think we should rework the .bochsrc file to be more standard across all
devices. I like how the USB configuration is done in it, and think we should
put something similar together for everything else. In otherwords, create
something that can be easily used for everything, and make it easier to
configure in the process.
From what I can tell right now, most of the configuration lines are randomly
thrown together as each gets implemented or added, instead of having
something that is based on a standard approach to the configuration.
The result should be something that would be able to easily auto-configured
by another program (a configuration editor?) with minimal changes necessary
when new devices/features are added.
14.2  Franck Cornelis wrote : the config system needs some work... 
e.g. the main menu is static while it could be generated at run-time...
the main menu text lives somewhere in a file... while it should be generated 
at run-time by iterating the main menu objects
Status:
The config options handling has been rewritten to a parameter tree.

15. Save/Restore
We already have a specific branch in the cvs with a save/restore
framework. The work still needs to be completed.
I guess it would be useful to be able to stop and
restart the emulation, or create "checkpoints"  to restart the
emulation from a known state. We can also give a look on how
integrate commitable harddisks with the save/restore strategy.
Status:
Save/restore of config and log options and the hardware state is supported now.
Harddisk images are not handled yet.

16. add to the roadmap that we should find some ideas to check 
correctness of instructions emulation, especially system instructions.  
arithmetic instructions could be validated with simply random testing
Status:
Not done yet.

17. lowlevel serial support for Windows.
Volker is currently working on this.
Status:
Not yet complete (transmit works, receive is losing data).

18. Parallel port
Conn Clark wrote :
I would like to see better parallel port support so I can use a dongle. 
This is something I would find very useful as it would mean I wouldn't 
have to boot back into windows ever again. I also recognize that this 
may require a kernel module be written, which is beyond my current 
skills.  I know others will find this useful as I have had to tell a 
few people that their parallel port driven peripherals that require a 
bidirectional parallel port won't work.
Status:
Not done yet.

19. Patches / Bug reports
There are dozens of patches floating around. Some are outdated,
don't apply cleanly, are obsolete/unneeded. We could try to do 
some clean-up, and keep only relevent ones.
We should also clean up the SF bug tracker. Some bugreports are 
very old and we asked for more information with no response.
Status:
There is some progress, but still a lot of work to do.

20. Positions
If you want to help without coding, here are available positions :
20.1 Webmaster : update website (Jan Bruun Andersen offered to help)
22.2 patch coordonator : look at incoming patches (sourceforge and 
mailing list) and upload / update in the cvs patches directory.
20.3 platform maintainers for macos / win32 
20.4 disk image maintainer : create and maintain our collection
of disk images. Usually, only the configuration file needs to be
updated, and old bios files have to be removed.  Some packages 
still contain very old bios files, they should definitely have
to be removed.
Status:
More active developers are needed to do the things described above.

21. Bochs demo cd/dvd
With version 2.1, it is now technically possible to use disk images 
on a read-only media, with a journal files on a read/write media. 
It would be great to create a demo cd/dvd with executables for 
supported platforms, configuration files and read-only disk 
images, the journal files would be written in a temporary 
directory on the harddisk.
Status:
Not done yet.

22. Other CPU architectures : arm, ppc 
This has been asked in the mailing list. I'm not really
interested, but other people might be. Should we propose to 
host the new CPUs code in our source tree, or should we let 
people fork ?
Status:
Not done yet.