Difference between revisions of "Development/SettingUpBochs"

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== Disk image ==
== Disk image ==
To create a disk image, checkout [http://bochs.sourceforge.net/doc/docbook/user/howto.html#DISKIMAGEHOWTO here] or [http://kbarr.net/bochs here].
To create a disk image, checkout [http://bochs.sourceforge.net/doc/docbook/user/diskimagehowto.html here] or [http://kbarr.net/bochs here].
See also [[What_is_a_SYSLINUX_disk_%3F]] and [[Hard_disk_images]]
In a nutshell:
In a nutshell:

Latest revision as of 13:21, 20 June 2014


Download the latest sources at Sourceforge.

./configure --enable-all-optimisations \
            --enable-pci \
            --enable-ne2000 \
            --enable-pnic \
            --with-term \
            --enable-disasm \
            --enable-debugger \


Save the following in a bochsrc file:

vgaromimage: file=/path/to/bochs/bios/VGABIOS-elpin-2.40
vga: extension=none
romimage: file=/path/to/bochs/bios/BIOS-bochs-latest    
cpu: count=1, ips=10000000, reset_on_triple_fault=0
megs: 32    
optromimage1: file=/path/to/gpxe/src/bin/pnic.rom, address=0xd0000
ne2k: ioaddr=0x280, irq=10, mac=fe:fd:00:00:00:01, ethmod=tuntap, ethdev=/dev/net/tun
ata0: enabled=1, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
ata1: enabled=1, ioaddr1=0x170, ioaddr2=0x370, irq=15
ata0-master: type=disk, path=/path/to/disk.img, mode=flat, translation=none
log: bochsout.txt
debugger_log: bochsdbg.txt
panic: action=ask
error: action=report
info: action=report
debug: action=ignore
mouse: enabled=0
display_library: term
boot: network

Disk image

To create a disk image, checkout here or here.

See also What_is_a_SYSLINUX_disk_? and Hard_disk_images

In a nutshell:

  1. Create a disk image using bximage
  2. Setup the partition table with fdisk
  3. Install the Master boot record (when using losetup to create a device, don't specify any offset)
  4. Format the disk (make sure to set the right offset when using losetup)
  5. Run extlinux
  6. Create a Syslinux configuration file and install necessary modules

There is a ready to use image available on github.


./bochs -q -f /path/to/bochsrc


bochs provides 3 different NICs, ne2k-isa, ne2k-pci and pnic. The only difference between ne2k-isa and ne2k-pci is inserting the ne2k NIC into a PCI slot (thereby ignoring the ioaddr and irq settings).


The BOCHS ethmod vnet has the advantage of not requiring elevated privileges (a la root) but the disadvantage of only providing DHCP, read-only TFTP and ICMP echo support (possibly a little more but not much)


So far, I haven't been able to get gPXE and the BOCHS DHCP server to like each other using BOCHS's vnet ethmod. However, vnet is a fixed IP configuration.

ifopen net0
# either gPXE or the BOCHS DHCP doesn't like this:
# dhcp net0

set net0/ip
set net0/netmask
set net0/dns
set net0/gateway ${net0/dns}
set net0/next-server ${net0/dns}
set net0/filename pxelinux.0
# Verify settings with user
config net0

chain ${net0/filename}

To create an image:

  • Save the script into bochs.gpxe
  • Clone the gpxe tree: git://git.etherboot.org/scm/gpxe.git
  • make EMBEDDED_IMAGE=/path/to/bochs.gpxe ISOLINUX_BIN=/path/to/syslinux/core/isolinux.bin
  • OR: make ne2k-isa.dsk EMBEDDED_IMAGE=/path/to/bochs.gpxe (or gpxe.dsk instead of ne2k-isa.dsk)


I had to alter the default IRQ as 9 was taken by the PCI bridge. The MAC is a special MAC address that BOCHS uses for certain ethmod networks. Replace "/tftpboot" with your appropriate TFTP root directory.

ne2k: enabled=1, ioaddr=0x300, irq=10, mac=fe:fd:00:00:00:01, ethmod=vnet, ethdev=/tftpboot, script=none

I've been able to get this to work with my gPXE script embedded into a floppy image with the ne2k-isa gPXE driver (feel free to use all-drivers if you like).

To boot it via a floppy drive, add the following to your bochsrc:

floppya: 1_44="/path/to/gpxe/src/bin/gpxe.dsk", status=inserted
boot: floppy


So far, I haven't been successful with the PNIC psuedo NIC on the vnet ethmod. gPXE reports PCI 10ec:8029 as ns8390 but didn't seem to take (even with all-drivers; full ID: 10ec:8029 0000:0000).