Bochs/bochs/CHANGES

-------------------------------------------------------------------------
Changes in 1.3 (December 10, 2001):
- networking works on Windows and Linux platforms
- emulated cdrom can now read from ISO image files, on any platform.
- new PIT model by Greg Alexander which is much more complete than the
  old one.  The new PIT is used by default, but you can switch back to 
  the old one if you configure with --disable-new-pit.
  (PIT = 8254 programmable interrupt timer)
- new configuration menus by Bryce Denney, which allow you to change any
  bochsrc option using text menus, then save the configuration into
  a new bochsrc file for later use.  You can disable the new code using
  configure --disable-control-panel.  Also you can use the command
  line arguments -nocp or -nocontrolpanel.  Also, there is a new
  "Config" button on the GUI that allows limited changes to the 
  configuration at runtime, such as changing the floppy disk.
- add docbook documentation directory in the sources under doc/docbook.
  The transition from HTML to docbook documentation is still in progress.
- Add new log action "ask", as shown in these example bochsrc lines:
    panic: action=ask
    error: action=ask
  When an event occurs which is set to "ask", you get a beep and message
  on the text terminal that asks what you want to do.  Choices are: continue,
  continue and disable future messages from this device, quit immediately,
  or segfault (where abort() function is available).  If compiled with
  --enable-debugger, you can also choose to enter the debugger.
- Parallel port emulation cleaned up by Volker Ruppert.  See .bochsrc for
  syntax of new parport1 line in bochsrc.
- PCI support improved by Volker Ruppert, including BIOS changes.  Still
  not complete.
- floppy controller returns a proper error response if you try to write
  a read-only disk image.  For systems such as DOS that actually use the BIOS
  services, it was also necessary to add code in int13_diskette_function to
  recognize a write-protected error and return the correct error status code
  (AH=3, Carry Set).
- the ROM BIOS now prints panic messages to the console.  Thanks to Cliff
  Hones for his console display code.
- the ROM BIOS detects nonbootable disks (Barry Allard), and prints a message
  on the console.  Barry Allard's patch who helped with checking the boot
  signature.
- LBA support added for hard disks.  (Not tested very much.)
- add dependencies to makefiles
- logging code moved into a separate file, logio.cc
- new option --enable-slowdown-timer, by Greg Alexander, which kicks in if
  Bochs simulation time starts to run faster than real time.  This helps to
  keep the Bochs clock in sync with the real clock when the CPU is mostly
  idle.
- new option --enable-iodebug, by Dave Poirier, which creates an I/O
  interface to the debugger.  This lets you write software to be emulated
  in Bochs which can turn on instruction, register, or memory tracing
  using I/O accesses.
- improved detection of readline in configure script
- configure substitutes the version number into many files, instead of
  using sed in the makefile.  There are still a few uses of sed remaining.
- you can now use environment variables in bochsrc values.  For example,
  diskd: file="$BOCHS_IMG/diskd.img", cyl=615, heads=6, spt=17
- configure with --prefix=PATH works now
- running configure from a different directory works now, thanks to 
  a patch from Edouard G. Parmelan
- fix [ #433759 ] virtual address checks can overflow.
  > Bochs has been crashing in some cases when you try to access data which
  > overlaps the segment limit, when the segment limit is near the 32-bit
  > boundary.  The example that came up a few times is reading/writing 4 bytes
  > starting at 0xffffffff when the segment limit was 0xffffffff.  The
  > condition used to compare offset+length-1 with the limit, but
  > offset+length-1 was overflowing so the comparison went wrong.
- cmpxchg8b patch from Michael Hohmuth <hohmuth@innocent.com>
- apply patch from Thomas Fitzsimmons <fitzsim@cygnus.com> to fix compile
  problems when BX_SUPPORT_PAGING and BX_USE_TLB are turned off
- fix bug introduced in 1.2.1 which caused spurious exceptions.
  See patch #439314, Exception 1 (debug) on HALT, from
  thomas.petazzoni@meridon.com.
- add panic in ctrl_xfer32.cc where the IRET32 implementation is broken.
  This only happens if you are NOT in vm8086 mode or protected mode.
  The intent is to warn people when they are getting bad emulation, and
  encourage people to report how they got to that point.
- apply patch from Santiago Bazerque.  See this bug report:
  [ #463018 ] retf not removing parameters sometimes
- fix bug [ #461730 ] IRETD causes problems if NT-flag is set
  reported by Peter Lammich.
- apply patch [ #455014 ] CR0 bug in 80486, described as:
  > In the register CR0, when the bit PM is enabled, the bit 4 is 0
  > when should be 1.
- apply patch from Mike Rieker <mrieker@o3one.org> associated with this bug
  report: [ #480422 ] gdt 'accessed' bit
- in task_switch when it tried to ensure that the old TSS was paged in,
  it actually used the new TSS address, fixed.
- updated the instrumentation code, and added a working example.  To try
  it, configure --enable-instrumentation=instrument/example1.  Then when
  you run bochs, you will get one line for each instruction PC and for
  each I/O access in a new file called bxevent.txt.
- set a bit in the CMOS that says the processor has an FPU.  This is
  from patch [ #455006 ] Device byte is not initialized aptly.
  Author did not leave their name.
- add logging code to the "null ethernet" which does not require host OS
  support.  All this does is print the outgoing packets from the guest OS.
- cleanup of log functions (Todd Fries)
- add BX_ERROR for every command in ATAPI-6 that bochs does not support.
  I still need to do add some commands from older specs that are obsolete
  (and not listed) in ATAPI-6.  Commands that aren't in the spec will still
  panic.
- only put 0xf into the 2nd hard disk field when the cdrom is not present.
  This is a patch from Volker Ruppert <Volker.Ruppert@t-online.de>, who
  comments: "The fdisk command reports an unusable second harddisk if the cdrom
  is enabled. This patch helps, but I don't know if it is the right way."
- make hard disk code return error codes when data is not available instead
  of just panicing.  In particular, if the logical sector is out of bounds
  or the disk image cannot be read/written at the desired offset, we now
  abort the ATA command and return an error code.  Many of the old BX_PANIC
  messages are turned to BX_ERROR, so they will still appear in the
  log, but now the device model will try to communicate this fact to
  the OS instead of simply giving up.
- don't blindly reject odd length atapi commands.  There are cases when
  it's really ok according to ATA-4.
- for big endian machines, reversed the bit fields in interrupt_reason.
  This was pointed out by Nicholai Benalal.
- extended keyboard improvements by Dave Poirier
- major mouse patch from Dave Spring, that implements several missing 
  mouse modes.
- commit keyboard patch from David Haslam <dch@sirius.clara.co.uk>
  posted to mailing list, that addresses the problem of each key press
  printing ^@.  See cvs log for details.
- mouse performance fixes by Greg Alexander and Robb Main
- NE2000 fixes by Frode Vatvedt Fjeld, ecelca@yahoo.com, Greg Alexander,
  and angelos@openbsd.org.
- fix bug [ #468340 ] pic:slave: OCW3 not implemented.  Some event handling
  code appeared in the master pic but not the slave pic.
- fix compile problems in SB16 code, related to fpos_t being treated as 
  an integer.
- patch from Volker Ruppert <Volker.Ruppert@t-online.de> to fix
  midi output file so that winamp can play it.
- some cleanup of serial code by Todd Fries and Volker Ruppert, but it
  doesn't work yet.

X Windows specific:
- commit patch from David Haslam <dch@sirius.clara.co.uk>
  [ #455763 ] Cursor trail with DOS Edit/Minix vi
- error for missing fonts now points to the documentation
- new option --enable-idle-hack, by Roland Mainz, which makes Bochs more
  friendly toward other processes when its CPU is idle.  Presently, 
  this option is specific to X windows.

Win32 specific:
- now Windows 95/98/ME can read the physical cdrom (Don Becker)
- The default configuration for Win32 VC++, given in .conf.win32-vcpp,
  now enables the NE2000 and renames all .cc files to .cpp.  This keeps VC++
  happy but may make it hard to use CVS.
- The default configuration for Cygwin, given in .conf.win32-cygwin, now
  enables cdrom and SB16.
- See "new docs" on the web site for compile instructions for VC++ and Cygwin.
- The sources include a VC++ workspace, in addition to the old "nmake"
  makefile.
- ethernet support (emulated NE2000 card), coded by Don Becker.  This
  implementation requires a library called WinPCap, which you can 
  download from http://netgroup-serv.polito.it/winpcap.
- new utility called niclist.exe which lists the ID number of all your network
  cards (well probably you just have one).  The ID be used when setting up your
  .bochsrc.
- patch [ #466403 ] make text colors more accurate.  The author did not leave
  his/her name.
- fix GUI bug [ #452159 ] win32: mouse stuck if bochs win partly off screen
  Now we center the mouse periodically, whether or not the mouse has
  wandered outside of the window or not.
- event handler recognizes the extended keycode flag
- fixes for raw floppy and floppy disk images (Don Becker)

Linux specific:
- Ethernet (emulated NE2000 card) now works in Linux!  Contributed by
  splite@purdue.edu.  This has been tested using host OS kernel 2.2.14, and
  works with telnet, ftp, irc, lynx, etc.  Because it is a packet filter
  solution, you aren't able to talk to the host machine, only to other 
  machines on the network.  
- The default configuration for Linux, given in .conf.linux, now enables
  the NE2000 model.
- RPM build process configures with --prefix=/usr so that everything is
  installed in /usr/bochs instead of /usr/local/bochs.
- DLX Linux disk image is now installed so that only root can write it, to
  avoid security problems.  When you run the bochs-dlx script, it creates a
  local copy in your home directory and then runs it.
- code that determines the capacity of a cdrom now works for both ATAPI
  and SCSI drives (splite@purdue.edu)
- applied patch from bochs@sigint.cs.purdue.edu.  The comments are:
  > The Linux 2.4.5 CD-ROM driver sends a READ_DISC_INFO command which caused
  > an "unrecognized ATAPI command" panic.  Looks like READ_DISC_INFO is only
  > recognized by CD-R and CD-RW drives, so I ignore it for now.

Amiga MorphOS specific:
- Bochs now compiles and works on Amiga MorphOS.  Configure with
  --with-amigaos.  For AmigaOS only, see .bochsrc for use of fullscreeen and
  screenmode options.  The Amiga MorphsOS is written and maintained by
  Nicholai Benalal <nicholai@chello.se>.
- raw cdrom supported if you configure with --enable-cdrom

BeOS specific:
- Bochs compiles and works on BeOS.  Configure with --with-beos.
  Bernd Thorsten Korz <bernd.korz@insidebeos.de> maintains the BeOS port.
- raw cdrom supported if you configure with --enable-cdrom

MacOS X specific:
- Bochs now compiles and works on MacOS X.  Configure with --with-carbon.
  Emmanuel Mailliard <e.rsz@libertysurf.fr> ported the Macintosh code to the
  Carbon API.
- The MacOS X application is built using (gasp) mkdir, copy, and rez.
  Surely this is not the right way, but it works.
- raw cdrom supported if you configure with --enable-cdrom

RFB mode:
- apply patch.rfb-mouse by MURANAKA Masaki (monaka@users.sf.net)
  see this source forge bug [ #457968 ] Strange mouse motion on RFB
- add a retry loop in RFB code, so that if port 5900 is not available
  it can try 5901, etc.

Bochs Debugger:
- do a vga update whenever you print a debugger prompt.
- added debugger command "info fpu" that prints the FPU registers.  If you
  do "info all" you get cpu and fpu registers.
- added debugger command "info ne2k" which prints all the registers
  of the NE2000 model
- add ability to do register tracing and flag tracing (Dave Poirier).
  Try the trace-reg-on and trace-reg-off commands.
- instruction trace now includes time ticks
- fixed problems in which bochs compiled with debugger measured time 
  differently from bochs compiled without debugger.  Also when instruction
  trace was enabled, breakpoints and control-C did not work.  Also,
  breakpoints at the beginning of an interrupt handler did not work.

-------------------------------------------------------------------------
Changes in 1.2.1 (June 12, 2001):
- more work on makefile for building RPMs
- [ #432382 ] build debian packages patch
  add build/debian directory from Rob Lemley <rjlemley@calypsoblue.org>
  which allows us to make Debian packages!
- optimize for speed when simulating one processor.  Now 1-processor
  performance should be equivalent to 1.1.2.
- [ #425640 ] sb16 assumes fpos_t is long int
  This fixes compiles of iodev/sb16.cc on linux systems with newer libraries
  in which fpos_t is not an integer.
- [ #432488 ] SMP:assert "n_logfn < MAX_LOGFNS" fails
  increase MAX_LOGFNS since we ran out of them on an SMP simulation with
  4 processors
- changes to compile clean on cygwin:
  - don't use the WIN32 snprintf define for cygwin
  - add ssize_t definition for cygwin
  - only compile "struct timeval tval" if select is available
    on that platform.
- [ #432491 ] SMP: CPUID says no APIC feature
  clean up inconsistent use of BX_SUPPORT_APIC and BX_APIC_SUPPORT, which
  caused the CPUID to report no APIC was present
- [ #431025 ] --enable-external-device-models broken
  removed configure options for external-device-models and 
  external-cpu-memory.  These don't work and aren't going to be fixed.
- [ #429448 ] configure: -lreadline when not there
  Now configure allows you to choose not to use readline, even if it's found
  on your system.
- [ #428915 ] apply extended keyboard patch
  extended keyboard patch by Dave Poirier <eks@void-core.2y.net>
- [ #428626 ] if no X11 found, configure&make fails
  Now configure halts if X windows is selected but no X libraries are found.
- updated rombios to version 1.13.  This fixes several problems:
  - [ #430472 ] DOS HIMEM "A20 line" error
    This problem was apparantly caused when Bryce added a function that prints
    the BIOS version, and he called it too early in the boot process.  Now the
    same function is called later, and it doesn't break the A20.
  - [ #431010 ] SMP structure overwritten in v1.2
    SMP structures were getting overwritten by BCC-generated data, 
    preventing SMP operating systems from detecting that other processors
    were available.
  - [ #431016 ] bios: SMP struct has wrong entry count
    SMP structure had the wrong entry counts
- very minor doc updates (typos, replace broken link to mtools info)
- quit when the user clicks the power button, even if they have disabled
  panics.
- win32 now defaults to having mouse capture mode turned off.  For new users,
  it would be distressing for their mouse cursor to disappear until they
  pressed F12.
- [ #428222 ] vga font not installed
  added script called "install-x11-fonts" which should help people install
  the VGA font on X windows systems, if it isn't already there.

Changes in 1.2 (June 3, 2001):
- [ #427259 ] rombios HALT calls don't print
  Fixed bios/rombios.c HALT macro so that it writes the line number of the
  panic to the PANIC_PORT (port 0x400) and then does NOT do a halt 
  instruction.  Also changed iodev/unmapped.cc so that the line number written
  to PANIC_PORT is displayed as a BX_PANIC message.  Because the HALT
  macro now triggers the normal panic behavior, it can be controlled by
  the bochsrc.
- [ #429016 ] crash if no hard drive
  rombios used to call HALT macro if no hard drive was found. Now it only
  calls HALT if a hard drive has an illegal geometry.
- [ #425388 ] include source for simple disk img tool
  [ #428478 ] mkimg tool creates image 1 byte too big
  Added bximage tool, which makes empty floppy and hard disk images.
  It is now included in the top level Makefile, so it will get built
  by default on all platforms.
- [ #426036 ] eth_fbsd.cc compile problem on solaris26
  added configure test so that "configure --enable-ne2000" only
  includes the Berkeley Packet Filter code (eth_fbsd) if the header
  file <net/bpf.h> can be found.  If you don't have BPF the ne2000
  will not actually move packets, but at least it will compile clean now.
- [ #428214 ] 1.2.pre1 need documentation for binaries
  Write windows and linux specific documentation to be installed in
  binary releases.
- [ #429258 ] disable RESET for version 1.2
  Since soft reset was not completely working, I reverted the reset patch.
  Now it does panics on reset instead of trying to reboot, as the old
  bochs versions did.
- [ #428222 ] Should the linux RPM install vga font?
  now font/vga.pcf will be installed in the RPM package
- [ #429020 ] stop renaming the BIOS!!!
  new BIOS changes are now in BIOS-bochs-latest, instead of a BIOS 
  whose name changes every time we change anything!  To help distinguish
  different BIOS versions, the BIOS now prints its RCS Id into the
  log file.
- [ #428625 ] compile problem if SHOW_IPS is on
  removed extra paren that broke SHOW_IPS
- [ #428219 ] PCI doesn't compile with SMF=1
- [ #429375 ] pthreads detection broken
- [ #429073 ] configure: if no X11, makes bad config
- [ #429229 ] install current .bochsrc in binary rels
- install Tim's man pages on linux RPM
- BIOS prints messages in log in case of boot failure
- rewrote instructions for compiling in win32 (win32.txt)
- fixed link in HTML changelog.html to point to the real sources on SF.
- added missing LOG_THIS definition to gui/nogui.cc and gui/rfb.cc
- added additional check for null pointer in debugger exit routine
- added diskd to .bochsrc

Changes in version 1.2-pre1 (May 25, 2001):
- major cleanup of .bochsrc
- major cleanup of stderr output: prints bochs version information when
  starting, and at the end it tries to print the message that caused 
  bochs to quit.
- two hard disk support (diskd).  At present, you cannot have two 
  hard drives and a cdrom at the same time, because there is only
  one IDE controller with two channels.
- split hard disk support allows different partitions to be stored in
  different image files
- two new GUI choices: term mode and RFB mode.  Term is a text-only
  interface, and RFB creates a server that can be accessed using
  the AT&T VNC viewer.
- now Bochs can simulate an SMP machine, if you configure with
  --enable-processors=N.  Configuring more than one processor has
  a major performance impact, so the default is 1 processor.
  See SMP documentation for more details.
- to make SMP work, bx_mem and bx_cpu have been replaced with
  bx_mem_array[] and bx_cpu_array[].  The cpus are referenced through
  the BX_CPU(n) macro and memories through the BX_MEM(n).  Normal
  mode has one cpu and one memory, SMP mode has multiple cpu's and 
  one memory, cosimulation mode has multiple cpus and multiple memories.
- use --enable-cpu-level=6 to make Bochs claim to be a Pentium Pro.
  The only feature that requires CPU level 6 is apic support.
- new logging system by Todd Fries, which has 4 levels of event
  severity (panic, error, info, debug).  There are new .bochsrc
  options that control what action to take when a 
  panic/error/info/debug event occurs.
- now searches for .bochsrc, bochsrc, bochsrc.txt, and (on unix only)
  $HOME/.bochsrc.
- use GNU readline library if --enable-debugger is on, as long as readline
  can be found on the machine
- configure checks for existence strtoull and strtouq. if neither exists, 
  Bochs uses its own implementation
- applied patches from Cliff Hones <cliff@aonix.co.uk> to fix up the
  rombios.  This includes many improvements, which you can list by
  doing "cvs log -r 1.6 bios/rombios.c" or looking at cvsweb.
- added suggested geometries of larger disks to the documentation
- this is the first release to have official binary packages for win32
  and Linux.  There is a new "make rpm" in the top-level Makefile which
  will create an RPM of the current bochs directory.  To use this,
  become root and type "configure; make rpm".
- applied some FreeBSD patches from Maxim Sobolev (cdrom and serial).

Changes in version 1.1.2 (bugfix3, May 16, 2001):
- updated Elpin VGA BIOS to version 2.40, and changed pointer in .bochsrc
- fixed .conf.x86 script so that it uses c++ instead of egcs for C++ files
- now Makefile targets that recurse into subdirectories use double colons,
  so that it will always recurse into subdirectories.  Now a single make
  command should notice a modified source file in a subdir.
- fixed bug in bx_panic.  If BX_PANIC_IS_FATAL==0 and a (non-fatal) panic 
  occurs, it used to call bx_atexit() and then return.  It should never
  call bx_atexit, which starts to shut down the simulator, unless it's
  really going to quit!
- support 2.88 MB floppy disks
- since dataseghack is checked in as non-executable, invoke it with 
  "csh dataseghack"
- double fault patch from Thomas Petazzoni <thomas.petazzoni@ifrance.com>,
  sourceforge patch #423726.
- removed -fno-builtin from fpu makefiles
- redefine u_char, u_short, etc. in order to not conflict with system
  definitions of these same types.
- in cdrom.cc, remove the extern "C" { } structure around some of the
  header files.  This is no longer necessary.
- do not panic on hard disk command 0x1f2 (read sector count)
- in keyboard.cc:
  - apply Todd Fries' reset patch
  - recognize most of the "Grey" insert/delete/home/end/etc. keys the
    same as keypad keys.
  - removed panic on "kbd_ctrl_to_kbd(): got value of 0x??"
  - implement mouse command 0xf6 (set defaults)
- apply Suboner@aol.com's Xwindows timing patch from
  http://sourceforge.net/tracker/index.php?func=detail&aid=418730&group_id=12580&atid=312580
- remove all patches from patches subdir which have already been applied.
  The remaining ones are under consideration but not applied.

Changes in version 1.1.1 (bugfix2, April 9, 2001):
- in soundwin.cc, arg 3 should be typecast to LPWAVEFORMATEX
- in fpu_entry.c, Bryce mistyped his own initials!
- in configure.in and configure, define good defaults for VC++
   #define BX_64BIT_CONSTANTS_USE_LL 0
   #define inline __inline
   #define BX_NO_EMPTY_STRUCTS 1
   #define BX_NO_ATTRIBUTES 1
   #define BX_HAVE_HASH_MAP 0
- in config.h.in, fixed typo in #error message


Changes in version 1.1 (bugfix1, April 6, 2001):

(FIXED, patch #414360: update copyrights)
update headers.  Change copyright to 2001, replace config.h.in header with
the standard mandrake header that every other file uses.

(FIXED, patch #414356: inlines)
make macro to replace inline and static/extern keywords.  Then make 
define the macro appropriately based on configure.

(FIXED: patch #414234: macos-no-strdup)
--with-macos should force HAVE_STRDUP=0.

(FIXED, patch #403027: Fix mouse bugs in Linux and BSD)
Linux and BSD (maybe others) cause panic in mouse code.

(FIXED, patch #413851: const64bit patch)
VC++ does not allow "LL" after 64-bit constant.

(FIXED, patch #413859: fabs symbol conflict)
fpu code contains fabs, which conflicts with math library fabs.

(FIXED, patch #403004: Implement aborts on a few SET FEATURE commands...)
Implement aborts on a few SET FEATURE commands for ATA.

(FIXED, patch #402991: Update to iodev/vga.cc to add 3c3h read support)
Implement VGA enable register, at 0x3c3.

(FIXED, patch #403027: Fix mouse bugs in Linux and BSD)
Mouse panic in linux/BSD: 
KBD: io write 0x64: command = 0xD3(write mouse outb)

(FIXED, patch #414229: panic-is-fatal)
Allow user to decide if panic is fatal, or just a warning

(FIXED, patch #414230: sun-cdrom)
Support Sun CDROM

(FIXED, patch #413574: portable1)
there are cases where a pointer is cast to a 32-bit int,
then later cast to a pointer and dereferenced, which crashes any 64-bit
machine.

(FIXED, patch #413574: portable1)
some machines have no snprintf or strtoull.  include a replacement function
when needed.

(FIXED, patch #413574: portable1)
Some compilers don't allow "typedef struct { } foo;"

(FIXED, patch #413574: portable1)
Some people don't have hash_map.h, used in dbg_main.cc.  Disable this code
if hash_map.h not found.

(FIXED, patch #413574: portable1)
Some compilers can't handle labels at the end of a block, as in
   void main () { /*code*/ label: }  

(FIXED, patch #413574: portable1)
Most compilers can't handle __attribute__.  Use macro to define it away.

(FIXED, patch #413574: portable1)
if --enable-debugger, turn on --enable-disasm too.

(FIXED, patch #413574: portable1)
ome compilers can't handle any chars after an #endif

(FIXED, patch #413574: portable1)
wrong type arg1 of bx_dbg_watch and bx_dbg_unwatch.  The code in
lexer.l was calling it with integers (not booleans)

(FIXED, patch #413574: portable1)
in fpu code, "setcc" macro was implemented with braces inside parens,
which some compilers don't understand.

(FIXED, patch #413574: portable1)
in fpu_entry.c, FPU_load_int32 was consistently called with arg1 of
type (s32 *), but should be (u32 *)

(FIXED, patch #413574: portable1)
comment out sigcontext structure in fpu/stubs/asm/sigcontext.h because
it conflicted with sigcontext of other machines.  This struct was never
used by bochs anyway.

(FIXED, patch #414046: portable2)
move definition of missing library functions into osdep.h and osdep.cc,
include contents of macutils*.

(FIXED, patch #414061: win32-rawcd)
CDROM drive letter for WIN32 should not be hardcoded.

(FIXED, patch #414060: win32-rawfloppy)
Bypass fstat when opening WIN32 raw floppy disk.

(FIXED, patch #414226: pit-panic)
WinME install dies with panic:
bochs: panic, pit: outp(43h): comm Bh, mode 00, bcd 00 unhandled
I think I had a similar problem.  All three timers should support modes
0, 2, and 3.  Other modes really aren't implemented.