bochsrc(5)

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:

  diskc: file="$IMAGES/30M.sample", cyl=615, heads=6, spt=17

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

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. There are two choices of configuration interface: a text mode version called "textconfig" and a graphical version called "wx". The text mode version uses stdin/stdout and is always compiled in. The graphical version 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)
      beos native BeOS libraries
      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 wxWindows library, cross platform
      nogui no display at all

    NOTE: if you use the "wx" configuration interface, you must also use the "wx" display library.

    Example:
      display_library: x

romimage:
    You need to load a ROM BIOS into F0000-FFFFF. The BIOS controls what the PC does when it first powers on. Normally, you can use a precompiled BIOS in the bios/ directory of the source tree, named BIOS-bochs-latest. You can also use the environment variable $BXSHARE to specify the location of the BIOS.

    Examples:
      romimage: file=bios/BIOS-bochs-latest, address=0xf0000
      romimage: file=$BXSHARE/BIOS-bochs-latest, address=0xf0000

megs:
    Set this to the default number of Megabytes of memory you want to emulate. You may also pass the 'megs:N' option to bochs. The default is 32MB, since most OS's won't need more than that.

    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 arbitary 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 C0000.

    Examples:
      vgaromimage: bios/VGABIOS-elpin-2.40
      vgaromimage: bios/VGABIOS-lgpl-latest
      vgaromimage: $BXSHARE/VGABIOS-lgpl-latest

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 to use 'inserted'.

    Example:

    2.88M 3.5" Floppy:
      floppya: 2_88=path, status=ejected

    1.44M 3.5" Floppy:
      floppya: 1_44=path, status=inserted

    1.2M 5.25" Floppy:
      floppyb: 1_2=path, status=ejected

    720K 3.5" Floppy:
      floppya: 720k=path, status=inserted

    360K 5.25" Floppy:
      floppya: 360k=path, status=inserted

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 is enabled by default, with ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14

    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|undoable|growing|volatile], 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 transation 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 and volatile 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, cylinders, heads, and spt are mandatory for type=disk The path is mandatory for type=cdrom

    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
      - undoable : flat file with commitable redolog
      - growing : growing file
      - volatile : flat file 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:
    This defines a serial (COM) port. 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.

    Examples:
      com1: enabled=1, dev=/dev/ttyp7
      com1: enabled=0

parport1:
    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
      parport1: enabled=1, file="/dev/lp0"
      parport1: enabled=0

newharddrivesupport:
    This setting enables support for large hard disks, better CD recognition, and various other useful functions. You can set it to "enabled=1" (on) or "enabled=0" (off). It is recommended that this setting is left on unless you are having trouble with it.

    Example:
      newharddrivesupport: enabled=1

boot:
    This defines your boot drive. You can either boot from 'floppy', 'disk' or 'cdrom'. (legacy 'a' and 'c' are also supported)

    Example:
      boot: 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. verbage 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 = Only 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.

    dmatimer:

    Microseconds per second for a DMA cycle. Make it smaller to fix non-continous sound. 750000 is usually a good value. This needs a reasonably correct setting for IPS (see below).

    Example:
      sb16: midimode=1, midi=/dev/midi00,
      wavemode=1, wave=/dev/dsp, loglevel=2,
      log=sb16.log, dmatimer=600000

    NOTE: The example is wrapped onto three lines for formatting reasons, but it should all be on one line in the actual bochsrc file.

vga_update_interval:
    Video memory is scanned for updates and screen updated every so many virtual seconds. The default is 300000, about 3Hz. This is generally plenty. Keep in mind that you must tweak the 'ips:' directive to be as close to the number of emulated instructions-per-second your workstation can do, for this to be accurate.

    Example:
      vga_update_interval: 250000

keyboard_serial_delay:
    Approximate time in microseconds that it takes one character to be transfered from the keyboard to controller over the serial path.

    Example:
      keyboard_serial_delay: 200

keyboard_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.

    Example:
      keyboard_paste_delay: 100000

floppy_command_delay:
    Time in microseconds to wait before completing some floppy commands such as read, write, seek, etc., which normally have a delay associated. This was previous hardwired to 50,000.

    Example:
      floppy_command_delay: 50000

ips:
    Emulated Instructions Per Second. This is the number of IPS that bochs is capable of running on your machine. You can recompile Bochs, using instructions included in config.h (in the source code), to find your workstation's capability.

    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]
       Machine Mips
     ---------------------------------------------------
     650Mhz Athlon K-7 with Linux 2.4.x 2 to 2.5
     400Mhz Pentium II with Linux 2.0.x 1 to 1.8
     166Mhz 64bit Sparc with Solaris 2.x 0.75
     200Mhz Pentium with Linux 2.x 0.5

     [1] Mips are dependant on OS and compiler configuration in addition to processor clock speed.

    Example:
      ips: 1000000

clock:
    This defines the parameters of the clock inside Bochs.

    sync

    TO BE COMPLETED (see Greg explaination in bug #536329)

    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], 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 option prevents Bochs from creating mouse "events" unless a mouse is enabled. The hardware emulation itself is not disabled by this. You can turn the mouse on by setting enabled to 1, or turn it off by setting enabled to 0. Unless you have a particular reason for enabling the mouse by default, it is recommended that you leave it off.

    Example:
      mouse: enabled=1
      mouse: enabled=0

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

i440fxsupport:
    Enables limited i440fx PCI chipset support.

    Example:
      i440fxsupport: enabled=1

ne2k:
    Defines the characteristics of an attached ne2000 isa card :
       ioaddr=IOADDR,
       irq=IRQ,
       mac=MACADDR,
       ethmod=MODULE,
       ethdev=DEVICE,
       script=SCRIPT

    PROPERTIES FOR ne2k:

    ioaddr, irq: You probably won't need to change ioaddr and irq, unless there are IRQ conflicts.

    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 pysical 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

    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 optionnal, 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

    Examples:
      ne2k: ioaddr=0x240, irq=9, mac=b0:c4:20:00:00:00, ethmod=fbsd, ethdev=xlo
      ne2k: ioaddr=0x240, irq=9, mac=b0:c4:20:00:00:00, ethmod=linux, ethdev=eth0
      ne2k: ioaddr=0x240, irq=9, mac=b0:c4:20:00:00:01, ethmod=win32, ethdev=MYCARD
      ne2k: ioaddr=0x240, irq=9, mac=fe:fd:00:00:00:01, ethmod=tap, ethdev=tap0
      ne2k: ioaddr=0x240, irq=9, mac=fe:fd:00:00:00:01, ethmod=tuntap, ethdev=tun0, script=./tunconfig

keyboard_mapping:
    This enables a remap of a physical localized keyboard to a virtualized us keyboard, as the PC architecture expects. If enabled, the keymap file must be specified.

     Examples:
       keyboard_mapping: enabled=1, map=gui/keymaps/x11-pc-de.map

keyboard_type:
    Type of emulated keyboard sent back to the OS to a "keyboard identify" command. It must be one of "xt", "at" or "mf".

    Example:
      keyboard_type: mf

user_shortcut:
    This defines the keyboard shortcut to be sent when you press the "user" button in the headerbar. The shortcut string can be a combination of these key names: "alt", "bksp", "ctrl", "del", "esc", "f1", "f4", "tab", "win". Up to 3 keys can be pressed at a time.

    Example:
      user_shortcut: keys=ctrlaltdel

cmosimage:
    This defines image file that can be loaded into the CMOS RAM at startup.

    Example:
      cmosimage: cmos.img

usb1:
    Enables the i440fx PCI USB root hub. USB devices with access to real hardware are not implemented yet. PCI support must be enabled, too.

    Example:
      usb1: enabled=1, ioaddr=0xFF80, irq=10

diskc:
    or diskd:

    The diskc and diskd options are deprecated. Use ata* options instead.

    Point this at the disk image you want to use as for a hard disk. If you use bximage(1) to create the image, it will give you the required cyl, head, and spt information. diskc is the first hard drive, and diskd is the second hard drive.

    NOTE: You cannot use both diskd and cdromd together.

    Example:
      diskc: file=10M.i, cyl=306, heads=4, spt=17
      diskc: file=112M.i, cyl=900, heads=15, spt=17
      diskd: file=483.i, cyl=1024, heads=15, spt=63

cdromd:

    The cdromd option is deprecated. Use ata* options instead.

    Point this to a pathname of a raw CD-ROM device. There is no cdromc option, only cdromd.

    NOTE: You cannot use both diskd and cdromd together.

    Example:
      cdromd: dev=/dev/cdrom, status=inserted
      cdromd: dev=/dev/cdrom, status=ejected

pit:
    The pit option is deprecated. Use the clock option instead.

    The PIT is the programmable interval timer. It has an option that tries to keep the PIT in sync with real time. This feature is still experimental, but it may be useful if you want to prevent Bochs from running too fast, for example a DOS video game. Be aware that with the realtime pit option, your simulation will not be repeatable; this can a problem if you are debugging.

    Example:
      pit: realtime=1

time0:
    The time0 option is deprecated. Use the clock option instead.

    Specifies the start (boot) time of the virtual machine. Use a time value as returned by the time(2) system call. Time equal to 1 is a special case which starts the virtual machine at the current time of the simulator host.

    Example:
      time0: 938581955

LICENSE
This program is distributed under the terms of the GNU Lesser General Public License as published by the Free Software Foundation. See the COPYING file located in /usr/local/share/doc/bochs/ for details on the license and the lack of warrantee.

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)

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.