Provided by: bochs_2.6-5build2_amd64 
NAME
bochsrc - Configuration file for Bochs.
DESCRIPTION
Bochsrc is the configuration file that specifies where Bochs should look for disk images, how
the Bochs emulation layer should work, etc. The syntax used for bochsrc can also be used as
command line arguments for Bochs. The .bochsrc file should be placed either in the current directory
before running Bochs or in your home directory.
Starting with Bochs 1.3, you can use environment variables in the bochsrc file, for example:
floppya: 1_44="$IMAGES/bootdisk.img", status=inserted
Starting with version 2.0, two environment variables have a built-in default value which is set at
compile time. $BXSHARE points to the "share" directory which is typically /usr/local/share/bochs on UNIX
machines. See the $(sharedir) variable in the Makefile for the exact value. $BXSHARE is used by disk
images to locate the directory where the BIOS images and keymaps can be found. If $BXSHARE is not
defined, Bochs will supply the default value. Also, $LTDL_LIBRARY_PATH points to a list of directories
(separated by colons if more than one) to search in for Bochs plugins. A compile-time default is
provided if this variable is not defined by the user.
OPTIONS
#include
This option includes another configuration file. It is possible to put installation defaults in a
global config file (e.g. location of rom images).
Example:
#include /etc/bochsrc
plugin_ctrl:
Controls the presence of optional device plugins. These plugins are loaded directly with this
option and some of them install a config option that is only available when the plugin device is
loaded. The value "1" means to load the plugin and "0" will unload it (if loaded before).
These plugins will be loaded by default (if present): 'biosdev', 'extfpuirq',
These plugins are also supported, but they are usually loaded directly with their bochsrc option:
'e1000', 'es1370', 'ne2k', 'pcidev', 'pcipnic', 'sb16',
Example:
plugin_ctrl: unmapped=0, e1000=1 # unload 'unmapped' and load 'e1000'
config_interface:
The configuration interface is a series of menus or dialog boxes that allows you to change all the
settings that control Bochs's behavior. Depending on the platform there are up to 3 choices of
configuration interface: a text mode version called "textconfig" and two graphical versions called
"win32config" and "wx". The text mode version uses stdin/stdout and is always compiled in, unless
Bochs is compiled for wx only. The choice "win32config" is only available on win32 and it is the
default there. The choice "wx" is only available when you use "--with-wx" on the configure
command. If you do not write a config_interface line, Bochs will choose a default for you.
NOTE: if you use the "wx" configuration interface, you must also use the "wx" display library.
Example:
config_interface: textconfig
display_library:
The display library is the code that displays the Bochs VGA screen. Bochs has a selection of
about 10 different display library implementations for different platforms. If you run configure
with multiple --with-* options, the display_library command lets you choose which one you want to
run with. If you do not write a display_library line, Bochs will choose a default for you.
The choices are:
x X windows interface, cross platform
win32 native win32 libraries
carbon Carbon library (for MacOS X)
macintosh MacOS pre-10
amigaos native AmigaOS libraries
sdl SDL library, cross platform
term text only, uses curses/ncurses library, cross platform
rfb provides an interface to AT&T's VNC viewer, cross platform
wx wxWidgets library, cross platform
nogui no display at all
NOTE: if you use the "wx" configuration interface, you must also use the "wx" display library.
Specific options: Some display libraries now support specific options to control their behaviour.
These options are supported by more than one display library:
"gui_debug" - use GTK debugger gui (sdl, x)
"hideIPS" - disable IPS output in status bar (rfb, sdl, wx, x)
"nokeyrepeat" - turn off host keyboard repeat (sdl, x)
See the examples below for other currently supported options.
Examples:
display_library: x
display_library: rfb, options="timeout=60" # time to wait for client
display_library: sdl, options="fullscreen" # startup in fullscreen mode
romimage:
The ROM BIOS controls what the PC does when it first powers on. Normally, you can use a
precompiled BIOS in the source or binary distribution called BIOS-bochs-latest. The default ROM
BIOS is usually loaded starting at address 0xe0000, and it is exactly 128k long. The legacy
version of the Bochs BIOS is usually loaded starting at address 0xf0000, and it is exactly 64k
long. You can also use the environment variable $BXSHARE to specify the location of the BIOS.
The usage of external large BIOS images (up to 512k) at memory top is now supported, but we still
recommend to use the BIOS distributed with Bochs. The start address is optional, since it can be
calculated from image size.
Examples:
romimage: file=bios/BIOS-bochs-latest
romimage: file=$BXSHARE/BIOS-bochs-legacy
romimage: file=mybios.bin, address=0xfff80000
romimage: file=mybios.bin
cpu: This defines cpu-related parameters inside Bochs:
count:
Set the number of processors:cores per processor:threads per core when Bochs is compiled for SMP
emulation. Bochs currently supports up to 8 processors. If Bochs is compiled without SMP support,
it won't accept values different from 1.
quantum:
Maximum amount of instructions allowed to execute by processor before returning control to another
cpu. This option exists only in Bochs binary compiled with SMP support.
reset_on_triple_fault:
Reset the CPU when triple fault occur (highly recommended) rather than PANIC. Remember that if you
trying to continue after triple fault the simulation will be completely bogus !
cpuid_limit_winnt:
Determine whether to limit maximum CPUID function to 2. This mode is required to workaround WinNT
installation and boot issues.
mwait_is_nop:
When this option is enabled MWAIT will not put the CPU into a sleep state. This option exists
only if Bochs compiled with --enable-monitor-mwait.
msrs:
Define path to user CPU Model Specific Registers (MSRs) specification. See example in msrs.def.
ignore_bad_msrs:
Ignore MSR references that Bochs does not understand; print a warning message instead of
generating #GP exception. This option is enabled by default but will not be avaiable if
configurable MSRs are enabled.
ips:
Emulated Instructions Per Second. This is the number of IPS that Bochs is capable of running on
your machine. You can recompile Bochs with --enable-show-ips option enabled, to find your
workstation's capability. Measured IPS value will then be logged into your log file or status bar
(if supported by the gui).
IPS is used to calibrate many time-dependent events within the bochs simulation. For
example, changing IPS affects the frequency of VGA updates, the duration of time before a key
starts to autorepeat, and the measurement of BogoMips and other benchmarks.
Example Specifications[1]
Bochs Machine/Compiler Mips
──────────────────────────────────────────────────────────────
2.4.6 3.4Ghz Core i7 2600 w/ Win7x64/g++ 4.5.2 85-95 Mips
2.3.7 3.2Ghz Core 2 Q9770 w/ WinXP/g++ 3.4 50-55 Mips
2.3.7 2.6Ghz Core 2 Duo w/ WinXP/g++ 3.4 38-43 Mips
2.2.6 2.6Ghz Core 2 Duo w/ WinXP/g++ 3.4 21-25 Mips
2.2.6 2.1Ghz Athlon XP w/ Linux 2.6/g++ 3.4 12-15 Mips
[1] IPS measurements depend on OS and compiler configuration in addition to processor clock
speed.
Example:
cpu: count=2, ips=10000000, msrs="msrs.def"
cpuid: This defines features and functionality supported by Bochs emulated CPU:
mmx:
Select MMX instruction set support. This option exists only if Bochs compiled with BX_CPU_LEVEL
>= 5.
apic:
Select APIC configuration (LEGACY/XAPIC/XAPIC_EXT/X2APIC). This option exists only if Bochs
compiled with BX_CPU_LEVEL >= 5.
sep:
Select SYSENTER/SYSEXIT instruction set support. This option exists only if Bochs compiled with
BX_CPU_LEVEL >= 6.
sse:
Select SSE instruction set support. Any of NONE/SSE/SSE2/SSE3/SSSE3/SSE4_1/SSE4_2 could be
selected. This option exists only if Bochs compiled with BX_CPU_LEVEL >= 6.
sse4a:
Select AMD SSE4A instructions support. This option exists only if Bochs compiled with
BX_CPU_LEVEL >= 6.
aes:
Select AES instruction set support. This option exists only if Bochs compiled with BX_CPU_LEVEL
>= 6.
movbe:
Select MOVBE Intel(R) Atom instruction support. This option exists only if Bochs compiled with
BX_CPU_LEVEL >= 6.
adx:
Select ADCX/ADOX instructions support. This option exists only if Bochs compiled with
BX_CPU_LEVEL >= 6.
xsave:
Select XSAVE extensions support. This option exists only if Bochs compiled with BX_CPU_LEVEL >=
6.
xsaveopt:
Select XSAVEOPT instruction support. This option exists only if Bochs compiled with BX_CPU_LEVEL
>= 6.
avx:
Select AVX/AVX2 instruction set support. This option exists only if Bochs compiled with --enable-
avx option.
avx_f16c:
Select AVX float16 convert instructions support. This option exists only if Bochs compiled with
--enable-avx option.
avx_fma:
Select AVX fused multiply add (FMA) instructions support. This option exists only if Bochs
compiled with --enable-avx option.
bmi:
Select BMI1/BMI2 instructions support. This option exists only if Bochs compiled with --enable-
avx option.
fma4:
Select AMD four operand FMA instructions support. This option exists only if Bochs compiled with
--enable-avx option.
xop:
Select AMD XOP instructions support. This option exists only if Bochs compiled with --enable-avx
option.
tbm:
Select AMD TBM instructions support. This option exists only if Bochs compiled with --enable-avx
option.
x86_64:
Enable x85-64 and long mode support. This option exists only if Bochs compiled with x86-64
support.
1g_pages:
Enable 1G page size support in long mode. This option exists only if Bochs compiled with x86-64
support.
pcid:
Enable Process-Context Identifiers (PCID) support in long mode. This option exists only if Bochs
compiled with x86-64 support.
smep:
Enable Supervisor Mode Execution Protection (SMEP) support. This option exists only if Bochs
compiled with BX_CPU_LEVEL >= 6.
mwait:
Select MONITOR/MWAIT instructions support. This option exists only if Bochs compiled with
--enable-monitor-mwait.
vmx:
Select VMX extensions emulation support. This option exists only if Bochs compiled with --enable-
vmx option.
svm:
Select AMD SVM (Secure Virtual Machine) extensions emulation support. This option exists only if
Bochs compiled with --enable-svm option.
family:
Set family information returned by CPUID. Default family value determined by configure option
--enable-cpu-level.
model:
Set model information returned by CPUID. Default model value is 3.
stepping:
Set stepping information returned by CPUID. Default stepping value is 3.
vendor_string:
Set the CPUID vendor string returned by CPUID(0x0). This should be a twelve-character ASCII
string.
brand_string:
Set the CPUID vendor string returned by CPUID(0x80000002 .. 0x80000004). This should be at most a
forty-eight-character ASCII string.
Example:
cpuid: mmx=1, sep=1, sse=sse4_2, xapic=1, aes=1, movbe=1, xsave=1
megs: Set the number of Megabytes of physical memory you want to emulate. The default is 32MB, most
OS's won't need more than that. The maximum amount of memory supported is 2048Mb.
Example:
megs: 32
optromimage1: , optromimage2: , optromimage3: or optromimage4:
You may now load up to 4 optional ROM images. Be sure to use a read-only area, typically between
C8000 and EFFFF. These optional ROM images should not overwrite the rombios (located at
F0000-FFFFF) and the videobios (located at C0000-C7FFF). Those ROM images will be initialized by
the bios if they contain the right signature (0x55AA). It can also be a convenient way to upload
some arbitrary code/data in the simulation, that can be retrieved by the boot loader
Example:
optromimage1: file=optionalrom.bin, address=0xd0000
vgaromimage:
You also need to load a VGA ROM BIOS into 0xC0000.
Examples:
vgaromimage: file=bios/VGABIOS-elpin-2.40
vgaromimage: file=bios/VGABIOS-lgpl-latest
vgaromimage: file=$BXSHARE/VGABIOS-lgpl-latest
vga: This defines parameters related to the VGA display.
extension:
Here you can specify the display extension to be used. With the value 'none' you can use standard
VGA with no extension. Other supported values are 'vbe' for Bochs VBE and 'cirrus' for Cirrus SVGA
support.
update_freq:
The VGA update frequency is based on the emulated clock and the default value is 5. Keep in mind
that you must tweak the 'cpu: ips=N' directive to be as close to the number of emulated
instructions-per-second your workstation can do, for this to be accurate. If the realtime sync is
enabled with the 'clock' option, the value is based on the real time. This parameter can be
changed at runtime.
Examples:
vga: extension=cirrus, update_freq=10
vga: extension=vbe
floppya: or floppyb:
Point this to the pathname of a floppy image file or device. Floppya is the first drive, and
floppyb is the second drive. If you're booting from a floppy, floppya should point to a
bootable disk.
You can set the initial status of the media to 'ejected' or 'inserted'. Usually you will want to
use 'inserted'.
The parameter 'type' can be used to enable the floppy drive without media and status specified.
Usually the drive type is set up based on the media type.
The optional parameter 'write_protected' can be used to control the media write protect switch. By
default it is turned off.
Example:
2.88M 3.5" media:
floppya: 2_88=path, status=ejected
1.44M 3.5" media (write protected):
floppya: 1_44=path, status=inserted, write_protected=1
1.2M 5.25" media:
floppyb: 1_2=path, status=ejected
720K 3.5" media:
floppya: 720k=path, status=inserted
360K 5.25" media:
floppya: 360k=path, status=inserted
Autodetect floppy media type:
floppya: image=path, status=inserted
Use directory as 1.44M VFAT media:
floppya: 1_44=vvfat:path, status=inserted
1.44M 3.5" floppy drive, no media:
floppya: type=1_44
ata0: , ata1: , ata2: or ata3:
These options enables up to 4 ata channels. For each channel the two base io addresses and the irq
must be specified. ata0 and ata1 are enabled by default, with the values shown below.
Examples:
ata0: enabled=1, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
ata1: enabled=1, ioaddr1=0x170, ioaddr2=0x370, irq=15
ata2: enabled=1, ioaddr1=0x1e8, ioaddr2=0x3e0, irq=11
ata3: enabled=1, ioaddr1=0x168, ioaddr2=0x360, irq=9
ata[0-3]-master: or ata[0-3]-slave:
This defines the type and characteristics of all attached ata devices:
type= type of attached device [disk|cdrom]
path= path of the image
mode= image mode
[flat|concat|external|dll|sparse|vmware3|vmware4|undoable|growing|volatile|vpc|vvfat], only valid
for disks
cylinders= only valid for disks
heads= only valid for disks
spt= only valid for disks
status= only valid for cdroms [inserted|ejected]
biosdetect= type of biosdetection [none|auto], only for disks on ata0 [cmos]
translation=type of translation of the bios, only for disks [none|lba|large|rechs|auto]
model= string returned by identify device command
journal= optional filename of the redolog for undoable, volatile and vvfat disks
Point this at a hard disk image file, cdrom iso file, or a physical cdrom device. To create a
hard disk image, try running bximage. It will help you choose the size and then suggest a line
that works with it.
In UNIX it is possible to use a raw device as a Bochs hard disk, but WE DON'T RECOMMEND IT.
The path is mandatory for hard disks. Disk geometry autodetection works with images created by
bximage if CHS is set to 0/0/0 (cylinders are calculated using heads=16 and spt=63). For other
hard disk images and modes the cylinders, heads, and spt are mandatory. In all cases the disk size
reported from the image must be exactly C*H*S*512.
The mode option defines how the disk image is handled. Disks can be defined as:
- flat : one file flat layout
- concat : multiple files layout
- external : developer's specific, through a C++ class
- dll : developer's specific, through a DLL
- sparse : stackable, commitable, rollbackable
- vmware3 : vmware3 disk support
- vmware4 : vmware4 disk support (aka VMDK)
- undoable : flat file with commitable redolog
- growing : growing file
- volatile : flat file with volatile redolog
- vpc : fixed / dynamic size VirtualPC image
- vvfat: local directory appears as read-only VFAT disk (with volatile redolog)
The disk translation scheme (implemented in legacy int13 bios functions, and used by older
operating systems like MS-DOS), can be defined as:
- none : no translation, for disks up to 528MB (1032192 sectors)
- large : a standard bitshift algorithm, for disks up to 4.2GB (8257536 sectors)
- rechs : a revised bitshift algorithm, using a 15 heads fake physical geometry, for disks up to
7.9GB (15482880 sectors). (don't use this unless you understand what you're doing)
- lba : a standard lba-assisted algorithm, for disks up to 8.4GB (16450560 sectors)
- auto : autoselection of best translation scheme. (it should be changed if system does not
boot)
Default values are:
mode=flat, biosdetect=auto, translation=auto, model="Generic 1234"
The biosdetect option has currently no effect on the bios
Examples:
ata0-master: type=disk, path=10M.sample, cylinders=306, heads=4, spt=17
ata0-slave: type=disk, path=20M.sample, cylinders=615, heads=4, spt=17
ata1-master: type=disk, path=30M.sample, cylinders=615, heads=6, spt=17
ata1-slave: type=disk, path=46M.sample, cylinders=940, heads=6, spt=17
ata2-master: type=disk, path=62M.sample, cylinders=940, heads=8, spt=17
ata2-slave: type=disk, path=112M.sample, cylinders=900, heads=15, spt=17
ata3-master: type=disk, path=483M.sample, cylinders=1024, heads=15, spt=63
ata3-slave: type=cdrom, path=iso.sample, status=inserted
com1: , com2: , com3: or com4:
This defines a serial port (UART type 16550A). In the 'term' you can specify a device to use as
com1. This can be a real serial line, or a pty. To use a pty (under X/Unix), create two windows
(xterms, usually). One of them will run bochs, and the other will act as com1. Find out the tty
the com1 window using the `tty' command, and use that as the `dev' parameter. Then do `sleep
1000000' in the com1 window to keep the shell from messing with things, and run bochs in the other
window. Serial I/O to com1 (port 0x3f8) will all go to the other window.
Other serial modes are 'null' (no input/output), 'file' (output to a file specified as the 'dev'
parameter), 'raw' (use the real serial port - under construction for win32) and 'mouse' (standard
serial mouse - requires mouse option setting 'type=serial' or 'type=serial_wheel')
Examples:
com1: enabled=1, mode=term, dev=/dev/ttyp7
com2: enabled=1, mode=file, dev=serial.out
com1: enabled=1, mode=mouse
parport1: or parport2:
This defines a parallel (printer) port. When turned on and an output file is defined the emulated
printer port sends characters printed by the guest OS into the output file. On some platforms a
device filename can be used to send the data to the real parallel port (e.g. "/dev/lp0" on Linux).
Examples:
parport1: enabled=1, file=parport.out
parport2: enabled=1, file="/dev/lp0"
parport1: enabled=0
boot: This defines the boot sequence. Now you can specify up to 3 boot drives, which can be 'floppy',
'disk', 'cdrom' or 'network' (boot ROM). Legacy 'a' and 'c' are also supported.
Example:
boot: cdrom, floppy, disk
floppy_bootsig_check:
This disables the 0xaa55 signature check on boot floppies The check is enabled by default.
Example:
floppy_bootsig_check: disabled=1
log: Give the path of the log file you'd like Bochs debug and misc. verbiage to be written to. If you
really don't want it, make it /dev/null.
Example:
log: bochs.out
log: /dev/tty (unix only)
log: /dev/null (unix only)
logprefix:
This handles the format of the string prepended to each log line : You may use those special
tokens :
%t : 11 decimal digits timer tick
%i : 8 hexadecimal digits of cpu0 current eip
%e : 1 character event type ('i'nfo, 'd'ebug, 'p'anic, 'e'rror)
%d : 5 characters string of the device, between brackets
Default : %t%e%d
Examples:
logprefix: %t-%e-@%i-%d
logprefix: %i%e%d
panic: If Bochs reaches a condition where it cannot emulate correctly, it does a panic. This can be a
configuration problem (like a misspelled bochsrc line) or an emulation problem (like an
unsupported video mode). The "panic" setting in bochsrc tells Bochs how to respond to a
panic. You can set this to fatal (terminate the session), report (print information to the
console), or ignore (do nothing).
The safest setting is action=fatal. If you are getting panics, you can try action=report
instead. If you allow Bochs to continue after a panic, don't be surprised if you get strange
behavior or crashes if a panic occurs. Please report panic messages unless it is just a
configuration problem like "could not find hard drive image."
Example:
panic: action=fatal
error: Bochs produces an error message when it finds a condition that really shouldn't happen, but
doesn't endanger the simulation. An example of an error might be if the emulated software
produces an illegal disk command.
The "error" setting tells Bochs how to respond to an error condition. You can set this to
fatal (terminate the session), report (print information to the console), or ignore (do
nothing).
Example:
error: action=report
info: This setting tells Bochs what to do when an event occurs that generates informational
messages. You can set this to fatal (that would not be very smart though), report (print
information to the console), or ignore (do nothing). For general usage, the "report"
option is probably a good choice.
Example:
info: action=report
debug: This setting tells Bochs what to do with messages intended to assist in debugging. You can
set this to fatal (but you shouldn't), report (print information to the console), or ignore
(do nothing). You should generally set this to ignore, unless you are trying to diagnose a
particular problem.
NOTE: When action=report, Bochs may spit out thousands of debug messages per second, which
can impact performance and fill up your disk.
Example:
debug: action=ignore
debugger_log:
Give the path of the log file you'd like Bochs to log debugger output. If you really don't want
it, make it '/dev/null', or '-'.
Example:
log: debugger.out
log: /dev/null (unix only)
log: -
sb16: This defines the SB16 sound emulation. It can have several of the following properties. All
properties are in this format:
sb16: property=value
PROPERTIES FOR sb16:
midi:
The filename is where the midi data is sent. This can be a device or just a file if you
want to record the midi data.
midimode:
0 = No data should be output.
1 = output to device (system dependent - midi
denotes the device driver).
2 = SMF file output, including headers.
3 = Output the midi data stream to the file
(no midi headers and no delta times, just
command and data bytes).
wave:
This is the device/file where wave output is stored.
wavemode:
0 = no data
1 = output to device (system dependent - wave
denotes the device driver).
2 = VOC file output, including headers.
3 = Output the raw wave stream to the file.
log:
The file to write the sb16 emulator messages to.
loglevel:
0 = No log.
1 = Resource changes, midi program and bank changes.
2 = Severe errors.
3 = All errors.
4 = All errors plus all port accesses.
5 = All errors and port accesses plus a lot
of extra information.
It is possible to change the loglevel at runtime.
dmatimer:
Microseconds per second for a DMA cycle. Make it smaller to fix non-continuous sound. 750000 is
usually a good value. This needs a reasonably correct setting for the IPS parameter of
the CPU option. It is possible to adjust the dmatimer at runtime.
Example for output to OSS:
sb16: midimode=1, midi=/dev/midi00,
wavemode=1, wave=/dev/dsp, loglevel=2,
log=sb16.log, dmatimer=600000
Example for output to ALSA:
sb16: midimode=1, midi=alsa:128:0,
wavemode=1, wave=alsa,
log=sb16.log, dmatimer=600000
Example for output using SDL:
sb16: wavemode=1, wave=sdl
NOTE: The examples are wrapped onto three lines for formatting reasons, but it should all be
on one line in the actual bochsrc file.
es1370:
This defines the ES1370 sound emulation. The parameter 'enabled' controls the presence of the
device. The 'wavedev' parameter is similar to the 'wave' parameter of the SB16 soundcard. The
emulation supports recording and playback (except DAC1+DAC2 output at the same time).
Examples:
es1370: enabled=1, wavedev="" # win32
es1370: enabled=1, wavedev=alsa # Linux with ALSA
es1370: enabled=1, wavedev=sdl # use SDL audio (if present) for output
keyboard:
This defines parameters related to the emulated keyboard:
type:
Type of keyboard return by a "identify keyboard" command to the keyboard controller. It must be
one of "xt", "at" or "mf". Defaults to "mf". It should be ok for almost everybody. A known
exception is french macs, that do have a "at"-like keyboard.
serial_delay:
Approximate time in microseconds that it takes one character to be transferred from the keyboard
to controller over the serial path.
paste_delay:
Approximate time in microseconds between attempts to paste characters to the keyboard controller.
This leaves time for the guest os to deal with the flow of characters. The ideal setting depends
on how your operating system processes characters. The default of 100000 usec (.1 seconds) was
chosen because it works consistently in Windows.
If your OS is losing characters during a paste, increase the paste delay until it stops losing
characters.
keymap:
This enables a remap of a physical localized keyboard to a virtualized us keyboard, as the PC
architecture expects.
Examples:
keyboard: type=mf, serial_delay=200, paste_delay=100000
keyboard: keymap=gui/keymaps/x11-pc-de.map
clock: This defines the parameters of the clock inside Bochs.
sync
This defines the method how to synchronize the Bochs internal time with realtime. With the value
'none' the Bochs time relies on the IPS value and no host time synchronization is used. The
'slowdown' method sacrifices performance to preserve reproducibility while allowing host time
correlation. The 'realtime' method sacrifices reproducibility to preserve performance and host-
time correlation. It is possible to enable both synchronization methods.
time0
Specifies the start (boot) time of the virtual machine. Use a time value as returned by the
time(2) system call. If no time0 value is set or if time0 equal to 1 (special case) or if time0
equal 'local', the simulation will be started at the current local host time. If time0 equal to 2
(special case) or if time0 equal 'utc', the simulation will be started at the current utc time.
Syntax:
clock: sync=[none|slowdown|realtime|both], time0=[timeValue|local|utc]
Default value are sync=none, time0=local
Example:
clock: sync=realtime, time0=938581955 # Wed Sep 29 07:12:35 1999
mouse: This defines parameters for the emulated mouse type, the initial status of the mouse capture and
the runtime method to toggle it.
type
With the mouse type option you can select the type of mouse to emulate. The default value is
'ps2'. The other choices are 'imps2' (wheel mouse on PS/2), 'serial', 'serial_wheel' and
'serial_msys' (one com port requires setting 'mode=mouse'). To connect a mouse to an USB port, see
the 'usb_uhci',
enabled
The Bochs gui creates mouse "events" unless the 'enabled' option is set to 0. The hardware
emulation itself is not disabled by this. Unless you have a particular reason for enabling the
mouse by default, it is recommended that you leave it off. You can also toggle the mouse usage at
runtime (RFB, SDL, Win32, wxWidgets and X11 - see below).
toggle
The default method to toggle the mouse capture at runtime is to press the CTRL key and the middle
mouse button ('ctrl+mbutton'). This option allows to change the method to 'ctrl+f10' (like
DOSBox), 'ctrl+alt' (like QEMU) or 'f12' (replaces win32 'legacyF12' option).
Examples:
mouse: enabled=1
mouse: type=imps2, enabled=1
mouse: type=serial, enabled=1
mouse: enabled=0, toggle=ctrl+f10
private_colormap:
Requests that the GUI create and use it's own non-shared colormap. This colormap will be used
when in the bochs window. If not enabled, a shared colormap scheme may be used. Once again,
enabled=1 turns on this feature and 0 turns it off.
Example:
private_colormap: enabled=1
pci: This option controls the presence of a PCI chipset in Bochs. Currently it only supports the i440FX
chipset. You can also specify the devices connected to PCI slots. Up to 5 slots are available. For
these combined PCI/ISA devices assigning to slot is mandatory if you want to emulate the PCI
model: cirrus, ne2k and pcivga. These PCI-only devices are also supported, but they are auto-
assigned if you don't use the slot configuration: e1000, es1370, pcidev, pcipnic, usb_ohci and
usb_xhci.
Example:
pci: enabled=1, chipset=i440fx, slot1=pcivga, slot2=ne2k
pcidev:
Enables the mapping of a host PCI hardware device within the PCI subsystem of the Bochs x86
emulator. This feature requires Linux as a host OS.
Example:
pcidev: vendor=0x1234, device=0x5678
The vendor and device arguments should contain the vendor ID respectively the device ID of the PCI
device you want to map within Bochs. The PCI mapping is still very experimental.
ne2k: Defines the characteristics of an attached ne2000 isa card :
ioaddr=IOADDR,
irq=IRQ,
mac=MACADDR,
ethmod=MODULE,
ethdev=DEVICE,
script=SCRIPT,
bootrom=BOOTROM
PROPERTIES FOR ne2k:
IOADDR, IRQ: You probably won't need to change ioaddr and irq, unless there are IRQ conflicts.
These parameters are ignored if the NE2000 is assigned to a PCI slot.
MAC: The MAC address MUST NOT match the address of any machine on the net. Also, the first byte
must be an even number (bit 0 set means a multicast address), and you cannot use ff:ff:ff:ff:ff:ff
because that's the broadcast address. For the ethertap module, you must use fe:fd:00:00:00:01.
There may be other restrictions too. To be safe, just use the b0:c4... address.
ETHMOD: The ethmod value defines which low level OS specific module to be used to access physical
ethernet interface. Current implemented values include
- fbsd : ethernet on freebsd and openbsd
- linux : ethernet on linux
- win32 : ethernet on win32
- tap : ethernet through a linux tap interface
- tuntap : ethernet through a linux tuntap interface
- slirp : ethernet backend for Slirp with builtin DHCP / TFTP servers
If you don't want to make connections to any physical networks, you can use the following
'ethmod's to simulate a virtual network.
- null : All packets are discarded, but logged to a few files
- vde : Virtual Distributed Ethernet
- vnet : ARP, ICMP-echo(ping), DHCP and TFTP are simulated
The virtual host uses 192.168.10.1
DHCP assigns 192.168.10.2 to the guest
The TFTP server use 'ethdev' for the root directory and doesn't
overwrite files
ETHDEV: The ethdev value is the name of the network interface on your host platform. On UNIX
machines, you can get the name by running ifconfig. On Windows machines, you must run niclist to
get the name of the ethdev. Niclist source code is in misc/niclist.c and it is included in
Windows binary releases.
SCRIPT: The script value is optional, and is the name of a script that is executed after bochs
initialize the network interface. You can use this script to configure this network interface, or
enable masquerading. This is mainly useful for the tun/tap devices that only exist during Bochs
execution. The network interface name is supplied to the script as first parameter.
BOOTROM: The bootrom value is optional, and is the name of the ROM image to load. Note that this
feature is only implemented for the PCI version of the NE2000.
Examples:
ne2k: ioaddr=0x300, irq=9, mac=b0:c4:20:00:00:00, ethmod=fbsd, ethdev=xlo
ne2k: ioaddr=0x300, irq=9, mac=b0:c4:20:00:00:00, ethmod=linux, ethdev=eth0
ne2k: ioaddr=0x300, irq=9, mac=b0:c4:20:00:00:01, ethmod=win32, ethdev=MYCARD
ne2k: ioaddr=0x300, irq=9, mac=fe:fd:00:00:00:01, ethmod=tap, ethdev=tap0
ne2k: ioaddr=0x300, irq=9, mac=fe:fd:00:00:00:01, ethmod=tuntap, ethdev=/dev/net/tun0,
script=./tunconfig
ne2k: ioaddr=0x300, irq=9, mac=b0:c4:20:00:00:01, ethmod=vde, ethdev="/tmp/vde.ctl"
ne2k: ioaddr=0x300, irq=9, mac=b0:c4:20:00:00:01, ethmod=vnet, ethdev="c:/temp"
ne2k: mac=b0:c4:20:00:00:01, ethmod=slirp, script=/usr/local/bin/slirp, bootrom=ne2k_pci.rom
pcipnic:
To support the Bochs/Etherboot pseudo-NIC, Bochs must be compiled with the --enable-pnic configure
option. It accepts the same syntax (for mac, ethmod, ethdev, script, bootrom) and supports the
same networking modules as the NE2000 adapter.
Example:
pnic: enabled=1, mac=b0:c4:20:00:00:00, ethmod=vnet
e1000: To support the Intel(R) 82540EM Gigabit Ethernet adapter, Bochs must be compiled with the
--eanble-e1000 configure option. The E1000 accepts the same syntax (for mac, ethmod, ethdev,
script, bootrom) and supports the same networking modules as the NE2000 adapter.
Example:
e1000: enabled=1, mac=52:54:00:12:34:56, ethmod=slirp, script=/usr/local/bin/slirp
user_shortcut:
This defines the keyboard shortcut to be sent when you press the "user" button in the header bar.
The shortcut string is a combination of maximum 3 key names (listed below) separated with a '-'
character.
Valid key names:
"alt", "bksl", "bksp", "ctrl", "del", "down", "end", "enter", "esc", "f1", ... "f12", "home",
"ins", "left", "menu", "minus", "pgdwn", "pgup", "plus", "right", "shift", "space", "tab", "up",
"win", "print" and "power".
Example:
user_shortcut: keys=ctrl-alt-del
cmosimage:
This defines image file that can be loaded into the CMOS RAM at startup. The rtc_init parameter
controls whether initialize the RTC with values stored in the image. By default the time0 argument
given to the clock option is used. With 'rtc_init=image' the image is the source for the initial
time.
Example:
cmosimage: file=cmos.img, rtc_init=time0
usb_uhci:
This option controls the presence of the USB root hub which is a part of the i440FX PCI chipset.
With the portX option you can connect devices to the hub (currently supported: 'mouse', 'tablet',
'keypad', 'disk', 'cdrom', 'hub' and 'printer').
The optionsX parameter can be used to assign specific options to the device connected to the
corresponding USB port. Currently this feature is only used to set the speed reported by device
and by the 'disk' device to specify an alternative redolog file of some image modes.
If you connect the mouse or tablet to one of the ports, Bochs forwards the mouse movement data to
the USB device instead of the selected mouse type. When connecting the keypad to one of the
ports, Bochs forwards the input of the numeric keypad to the USB device instead of the PS/2
keyboard.
To connect a 'flat' mode image as an USB hardisk you can use the 'disk' device with the path to
the image separated with a colon. To use other disk image modes similar to ATA disks the syntax
'disk:mode:filename' must be used (see below).
To emulate an USB cdrom you can use the 'cdrom' device name and the path to an ISO image or raw
device name also separated with a colon. An option to insert/eject media is available in the
runtime configuration.
The device 'printer' emulates the HP Deskjet 920C printer. The PCL data is sent to a file
specified in bochsrc.txt. The current code appends the PCL code to the file if the file already
existed. It would probably be nice to overwrite the file instead, asking user first.
Example:
usb_uhci: enabled=1, port1=mouse, port2=disk:usbstick.img
usb_uhci: enabled=1, port1=hub:7, port2=disk:growing:usbdisk.img
usb_uhci: enabled=1, port1=printer:printdata.bin, port2=cdrom:image.iso
usb_ohci:
This option controls the presence of the USB OHCI host controller with a 2-port hub. The portX
option accepts the same device types with the same syntax as the UHCI controller (see above).
Example:
usb_ohci: enabled=1
usb_xhci:
This option controls the presence of the experimental USB xHCI host controller with a 4-port hub.
The portX option accepts the same device types with the same syntax as the UHCI controller (see
above).
Example:
usb_xhci: enabled=1
user_plugin:
Load user-defined plugin. This option is available only if Bochs is compiled with plugin support.
Maximum 8 different plugins are supported. See the example in the Bochs sources how to write a
plugin device.
Example:
user_plugin: name=testdev
LICENSE
This program is distributed under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation. See the LICENSE and COPYING files located in /usr/share/doc/bochs/ for
details on the license and the lack of warranty.
AVAILABILITY
The latest version of this program can be found at:
http://bochs.sourceforge.net/getcurrent.html
SEE ALSO
bochs(1), bochs-dlx(1), bximage(1), bxcommit(1)
The Bochs IA-32 Emulator site on the World Wide Web:
http://bochs.sourceforge.net
Online Bochs Documentation
http://bochs.sourceforge.net/doc/docbook
AUTHORS
The Bochs emulator was created by Kevin Lawton (kevin@mandrakesoft.com), and is currently
maintained by the members of the Bochs x86 Emulator Project. You can see a current roster of members
at:
http://bochs.sourceforge.net/getinvolved.html
BUGS
Please report all bugs to the bug tracker on our web site. Just go to http://bochs.sourceforge.net,
and click "Bug Reports" on the sidebar under "Feedback".
Provide a detailed description of the bug, the version of the program you are running, the operating
system you are running the program on and the operating system you are running in the emulator.
bochsrc 28 Aug 2012 bochsrc(5)