bochsrc(5) The Bochs Project bochsrc(5)NAMEbochsrc - 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 com‐
mand 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. loca‐
tion 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', 'gameport', 'iodebug','parallel', 'serial',
'speaker' and 'unmapped'.
These plugins are also supported, but they are usually loaded
directly with their bochsrc option: 'e1000', 'es1370', 'ne2k',
'pcidev', 'pcipnic', 'sb16', 'usb_ohci', 'usb_uhci', 'usb_xhci'
and 'voodoo'.
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 "textcon‐
fig" 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 "win32con‐
fig" 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 1.2.x library, cross platform
sdl2 SDL 2.x library, cross platform
term text only, uses curses/ncurses library, cross
platform
rfb provides an interface to AT&T's VNC viewer, cross
platform
vncsrv use LibVNCServer for extended RFB(VNC) support
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, sdl2, x)
"hideIPS" - disable IPS output in status bar (rfb, sdl,
sdl2, vncsrv, wx, x)
"nokeyrepeat" - turn off host keyboard repeat (sdl, sdl2, x)
"timeout" - time (in seconds) to wait for client (rfb,
vncsrv)
See the examples below for other currently supported options.
Examples:
display_library: x
display_library: sdl, options="fullscreen" # startup in
fullscreen mode
display_library: sdl2, options="fullscreen" # startup in
fullscreen mode
cpu: This defines cpu-related parameters inside Bochs:
model:
Selects CPU configuration to emulate from pre-defined list of
all supported configurations. When this option is used and the
value is different from 'bx_generic', the parameters of the
CPUID option have no effect anymore. See the bochsrc sample for
supported values.
count:
Set the number of processors:cores per processor:threads per
core when Bochs is compiled for SMP emulation. Bochs currently
supports up to 14 threads (legacy APIC) or 254 threads (xAPIC or
higher) running simultaniosly. 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) specifi‐
cation. 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 Intel Core i7 2600 with Win7x64/g++ 4.5.2 85 to 95
Mips
2.3.7 3.2Ghz Intel Core 2 Q9770 with WinXP/g++ 3.4 50 to 55
Mips
2.3.7 2.6Ghz Intel Core 2 Duo with WinXP/g++ 3.4 38 to 43
Mips
2.2.6 2.6Ghz Intel Core 2 Duo with WinXP/g++ 3.4 21 to 25
Mips
2.2.6 2.1Ghz Athlon XP with Linux 2.6/g++ 3.4 12 to 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 emu‐
lated CPU:
level:
Set emulated CPU level information returned by CPUID. Default
value is determined by configure option --enable-cpu-level. Cur‐
rently supported values are 5 (for Pentium and similar proces‐
sors) and 6 (for P6 and later processors).
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.
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.
simd:
Select SIMD instructions support. Any of
NONE/SSE/SSE2/SSE3/SSSE3/SSE4_1/SSE4_2/AVX/AVX2/AVX512 could be
selected.
This option exists only if Bochs compiled with BX_CPU_LEVEL >=
6. The AVX choises exists only if Bochs compiled with --enable-
avx option.
sse4a:
Select AMD SSE4A instructions support. This option exists only
if Bochs compiled with BX_CPU_LEVEL >= 6.
misaligned_sse:
Select AMD Misaligned SSE mode 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.
sha:
Select SHA 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_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.
smap:
Enable Supervisor Mode Access Prevention (SMAP) 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.
Example:
cpuid: mmx=1, sep=1, sse=sse4_2, xapic=1, aes=1, movbe=1,
xsave=1
memory:
Set the amount of physical memory you want to emulate.
guest:
Set amount of guest physical memory to emulate. The default is
32MB, the maximum amount limited only by physical address space
limitations.
host:
Set amount of host memory you want to allocate for guest RAM
emulation. It is possible to allocate less memory than you want
to emulate in guest system. This will fake guest to see the non-
existing memory. Once guest system touches new memory block it
will be dynamically taken from the memory pool. You will be
warned (by FATAL PANIC) in case guest already used all allocated
host memory and wants more.
Example:
memory: guest=512, host=256
megs: The 'megs:' option sets the 'guest' and 'host' memory parameters
to the same value. In all other cases the 'memory' option should
be used instead.
Example:
megs: 32
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 0xfffe0000, and it is exactly
128k long. The legacy version of the Bochs BIOS is usually
loaded starting at address 0xffff0000, and it is exactly 64k
long. You can 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
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
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
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:
This parameter specifies the number of display updates per sec‐
ond. The VGA update timer now uses the realtime engine and the
default value is 5. This parameter can be changed at runtime.
Examples:
vga: extension=cirrus, update_freq=10
vga: extension=vbe
voodoo:
This defines the Voodoo Graphics emulation (experimental). Cur‐
rently supported models are 'voodoo1' and 'voodoo2'. The Voodoo2
support is not yet complete.
Example:
voodoo: enabled=1, model=voodoo1
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 char‐
acters 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 vir‐
tualized us keyboard, as the PC architecture expects.
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 combi‐
nation 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", "power", "print", "right", "scrlck",
"shift", "space", "tab", "up" and "win".
Examples:
keyboard: type=mf, serial_delay=200, paste_delay=100000
keyboard: keymap=gui/keymaps/x11-pc-de.map
keyboard: user_shortcut=ctrl-alt-del
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',
'serial_msys' (one com port requires setting 'mode=mouse') and
'bus' (if present). To connect a mouse to an USB port, see the
'usb_uhci', 'usb_ohci' or 'usb_xhci' option (requires PCI and
USB support).
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 DOS‐
Box), 'ctrl+alt' (like QEMU) or 'f12' (replaces win32 'lega‐
cyF12' option).
Examples:
mouse: enabled=1
mouse: type=imps2, enabled=1
mouse: type=serial, enabled=1
mouse: enabled=0, toggle=ctrl+f10
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
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 repro‐
ducibility while allowing host time correlation. The 'realtime'
method sacrifices reproducibility to preserve performance and
host-time correlation. It is possible to enable both synchro‐
nization methods.
rtc_sync
If this option is enabled together with the realtime synchro‐
nization, the RTC runs at realtime speed. This feature is dis‐
abled by default.
time0
Specifies the start (boot) time of the virtual machine. Use a
time value as returned by the time(2) system call or a string as
returned by the ctime(3) 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, rtc_sync=0, time0=local
Example:
clock: sync=realtime, time0=938581955 # Wed Sep 29 07:12:35
1999
clock: sync=realtime, time0="Sat Jan 1 00:00:00 2000" #
946681200
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 argu‐
ment 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
private_colormap:
Requests that the GUI create and use it's own non-shared col‐
ormap. 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
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|exter‐
nal|dll|sparse|vmware3|vmware4|undoable|grow‐
ing|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 phys‐
ical 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 autodetec‐
tion 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 sec‐
tors)
- 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
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 cor‐
rectly, 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 con‐
dition. 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: -
com1: , com2: , com3: or com4:
This defines a serial port (UART type 16550A). In the 'term'
mode 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 mess‐
ing 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' (stan‐
dard 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 charac‐
ters printed by the guest OS into the output file. On some plat‐
forms 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
sound: This defines the lowlevel sound driver and the wave (PCM) input
and output devices to be used by sound emulation devices. Possi‐
ble values for the driver parameter are 'default', 'dummy' (no
input/output), 'alsa' (if present) and 'sdl' (if present). For
some drivers the wave devices must be specified. If the 'wavein'
parameter is not set, Bochs uses the 'waveout' device for input,
too.
Example:
sound: driver=default, waveout=/dev/dsp. wavein=
speaker:
This defines the PC speaker output mode. In the 'sound' mode the
beep is generated by the square wave generator which is a part
of the lowlevel sound support. The 'system' mode is only avail‐
able on Linux and Windows. On Linux /dev/console is used for
output and on Windows the Beep() function. The 'gui' mode for‐
wards the beep to the related gui methods (currently only used
by the Carbon gui).
Example:
speaker: enabled=1, mode=sound
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:
enabled:
This optional property controls the presence of the SB16 emu‐
lation.
The emulation is turned on unless this property is used and
set to 0.
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).
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.
wavemode:
0=no data
1=output to device (system dependent. wave denotes the device
driver)
2=VOC file output, incl. headers
3=output the raw wave stream to the file
wave:
This is the file where the wave output is stored (wavemode 2
or 3)
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=128:0,
wavemode=1, wave="",
log=sb16.log, dmatimer=600000
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 (recording and playback
- except DAC1+DAC2 output at the same time). The parameter
'enabled' controls the presence of the device. The 'wavemode'
parameter can be used to redirect the output to a file (see
SB16). The 'wavefile' parameter is similar to the 'wave' parame‐
ter of the SB16 soundcard.
Example for using 'sound' parameters:
es1370: enabled=1, wavemode=1 Example for sending output to
file:
es1370: enabled=1, wavemode=2, wavefile=output.voc
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 : built-in Slirp support with 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 net‐
work.
- 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 param‐
eter. The 'slirp' module uses this parameter to specify a config
file for setting up an alternative IP configuration or addi‐
tional features.
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, eth‐
mod=linux, ethdev=eth0
ne2k: ioaddr=0x300, irq=9, mac=b0:c4:20:00:00:01, eth‐
mod=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=tun‐
tap, 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=slirp.conf,
bootrom=ne2k_pci.rom
pcipnic:
To support the Bochs/Etherboot pseudo-NIC, Bochs must be com‐
piled with the --enable-pnic configure option. It accepts the
same syntax (for mac, ethmod, ethdev, script, bootrom) and sup‐
ports 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=slirp.conf
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',
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.
The optionsX parameter can be used to assign specific options to
the device connected to the corresponding USB port. Currently
this feature is used to set the speed reported by device ('low',
'full', 'high' or 'super'). The availabe speed choices depend on
both HC and device. For the USB 'disk' device the optionsX
parameter can be used to specify an alternative redolog file
(journal) of some image modes. For 'vvfat' mode USB disks the
optionsX parameter can be used to specify the disk size (range
128M ... 128G). If the size is not specified, it defaults to
504M.
Example:
usb_uhci: enabled=1, port1=mouse, port2=disk:usbstick.img
usb_uhci: enabled=1, port1=hub:7, port2=disk:growing:usb‐
disk.img
usb_uhci: enabled=1, port2=disk:vvfat:vvfat,
options2=speed:full
usb_uhci: enabled=1, port1=printer:printdata.bin,
port2=cdrom:image.iso
usb_ohci:
This option controls the presence of the USB OHCI host con‐
troller with a 2-port hub. The portX parameter accepts the same
device types with the same syntax as the UHCI controller (see
above). The optionsX parameter is also available on OHCI.
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 parameter accepts
the same device types with the same syntax as the UHCI con‐
troller (see above). The optionsX parameter is also available on
xHCI. NOTE: port 1 and 2 are USB3 and only support super-speed
devices, but port 3 and 4 are USB2 and support speed settings
low, full and high.
Example:
usb_xhci: enabled=1
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.
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 Gen‐
eral 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 ALSObochs(1), bochs-dlx(1), bximage(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@man‐
drakesoft.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 19 Oct 2014 bochsrc(5)
