Bochs x86 Emulator
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.