OS/pintos-env/share/doc/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 coordinated. 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 2.5:
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 :
1.1 virtualization : plex86
1.2 dynamic translation : qemu
Status:
Some work has been done for Bochs 2.5 but still long way is ahead.

2 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. Specifically
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 group started a para-Bochs project exactly to reach above goals,
some beta version is already released.
The home page of the project: http://grid.hust.edu.cn/cluster/VirtualMachine/main.html

3. Plugin architecture
3.1 The plugin architecture can be reworked if we want to support
multiple similar devices like serial, 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"
3.2 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.
3.3 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:
Some 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. For most of the optional plugins the config parameter creation and
bochsrc parsing has been moved to the plugin code. Unknown bochsrc options are
now treated as plugin names and Bochs tries to load them.

4. 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 SVN and it has been updated for the new PCI
infrastructure, but the new code is untested yet.

5. 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:
Subfolders for disk imaging, sound, network and usb devices were created
under the iodev folder.

6. 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.

7. Random thoughts on disk emulation improvements :
7.1 autodetection of disk size / geometry
7.2 uml cow disk image support
7.3 compressed disk image support
7.4 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. Vmware4 disk images support was added in Bochs 2.3.5 release.
Coherency check for 'undoable' mode images added for Bochs 2.6.

8. net
8.1 bootable ethernet rom ?
8.2 user mode networking ?
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 SVN, but the status is unknown. PCI boot ROM support
has been added for Bochs 2.6. User mode networking currently requires the 'slirp'
program and it is not possible on all platforms. The slirp core should be added
to the Bochs sources.

9. Bios
9.1 add "jump table placeholder" and log missing function calls in the bios.
Check completness with Ralf Brown interrupt list.
Status:
Not done yet.
9.2 use Coreboot or SeaBios as possible alternatives/extensions to
Bochs Bios ROM we have.
Status:
Starting from Bochs 2.5 SeaBIOS is usable.

10. 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:
Version 0.7a of the LGPL'd VGABIOS has minimal support for the video
parameter table.

11. 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.

12. 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:
OHCI and UHCI host controller and 7 devices are known to work in Bochs.
USB xHCI support is present, but needs more testing.

13. Config file and dynamic menu
13.1 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 other words, 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.
13.2  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. Dynamic
menus are now implemented on win32.

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

15. 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.

16. Guest-To-Host Communication
Try to adapt VirtualBox guest-to-host communication methods into Bochs.
Having VirtualBox Shared Folders or VNAT support in Bochs could very 
simplify its usage.

17. 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 relevant 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.

18. Positions
If you want to help without coding, here are available positions :
19.1 Webmaster : update website (Jan Bruun Andersen offered to help)
19.2 patch coordinator : look at incoming patches (sourceforge and
mailing list) and upload / update in the SVN patches directory.
19.3 platform maintainers for macos / win32
19.4 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.

19. 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.

20. 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.