This article describes how to build LinuxBIOS v2 on FreeBSD and boot FreeBSD using LinuxBIOS and ADLO inside Qemu.
All steps outlined in this article have been performed using FreeBSD 7.0-BETA1. Other versions of FreeBSD might work, too, but have not been tested. The patches mentioned in this article have been created against LinuxBIOSv2, Revision 2897.
In order to build ADLO on FreeBSD, you need the following ports installed:
- devel/dev86. See details below.
To build LinuxBIOS on FreeBSD, you need
- lang/python. At the time of writing this article, that port installs Python 2.4. Possibly other version of Python also work but haven't been tried.
To boot FreeBSD in QEMU you need
- emulators/qemu with modifications. Please refer to the QEMU Build Tutorial for details.
See this page on how to download LinuxBIOS. I recomment you checkout the latest Version of LinuxBIOS v2 using Subversion.
Applying the required patches
The LinuxBIOS build process assumes that the make utility is GNU make. This isn't true on FreeBSD (or the other BSDs for that matter), where GNU make is installed as gmake.
A patch which addresses this can be found here. To download and apply this patch, run the following commands from the top-level directory of your LinuxBIOS source tree (e.g. /home/phs/LinuxBIOSv2):
$ ftp http://linuxbios.org/images/b/b6/LinuxBIOS_ADLO_FreeBSD.tgz $ tar xzf LinuxBIOS_ADLO_FreeBSD.tgz $ patch -p0 < LinuxBIOS_ADLO_FreeBSD.diff
In order to boot FreeBSD using LinuxBIOS, ADLO is used as a payload. Therefore, it must be build before the LinuxBIOS image can be built. Building ADLO on FreeBSD requires that the 8086 development environment is installed. See the following section for details.
ADLO is part of the LinuxBIOS v2 source tree. Assuming you have applied the required patches, it can be build by issuing the following commands from the top-level directory of your LinuxBIOS v2 source tree:
$ cd util/ADLO $ gmake
You will now find the ADLO payload at util/ADLO/payload.
Building the 8086 development environment
ADLO requires the devel/dev86 port which installs the 8086 development environment. This is a new port not yet included in the FreeBSD Ports tree, see Problem Report ports/117480. To build the port, download and extract the shell archive attached to the problem report.
$ ftp -o devel_dev.shar http://www.freebsd.org/cgi/query-pr.cgi?prp=117480-1-shar $ sh devel_dev.shar $ cd dev86 $ su # make install
This has to be done only once, before building ADLO. You don't have to reinstall the port if you rebuild ADLO.
$ cd targets $ ./buildtarget emulation/qemu-i386 $ cd emulation/qemu-i386/qemu-i386 $ gmake
Make sure you use the gmake utility on FreeBSD!
This should give you a file called qemu-bios.rom in targets/emulation/qemu-i386/qemu-i386. Copy this file to a convenient location, e.g. your home directory, and rename it to bios.bin.
$ cp qemu-bios.rom ~/bios.bin
You will need it later.
Booting FreeBSD inside QEMU
If you already have a FreeBSD installation inside QEMU, you can boot it using LinuxBIOS with the following command:
$ qemu -kernel-kqemu -hda freebsd.img -nographic -L .
This assumes, that there is a file called bios.bin in the current working directory that contains LinuxBIOS with an ADLO payload. The file freebsd.img should contain your FreeBSD installation. Make sure it uses the serial console, though, as graphical output will not work when booted using LinuxBIOS.
Installing FreeBSD inside QEMU
Installing FreeBSD inside QEMU is pretty straight forward. If you already have a working installation, you can skip this section.
First you need to create a QEMU disk:
$ qemu-img create freebsd.img 1024M
This will create a QEMU virtual disk named freebsd.img with a capacity of 1 GByte. Next, install the base system using one of the ISO files provided by the FreeBSD Project at ftp://ftp.freebsd.org/pub/FreeBSD/ISO-IMAGES-i386 and have QEMU use it as the boot device. In this example, the FreeBSD 7.0-BETA1 bootonly disc  is used:
$ qemu -kernel-kqemu -hda freebsd.img -cdrom 7.0-BETA1-i386-bootonly.iso -boot d
Inside the QEMU, perform an installation as you normally would. See the FreeBSD Handbook for details. After the installation has finished, boot up FreeBSD once without using LinuxBIOS.
$ qemu -kernel-kqemu -hda freebsd.img
In the FreeBSD installation running inside QEMU add the following to the file /boot/loader.conf:
This will cause FreeBSD to use the first serial port as a console. Both the Loader's and the Kernel's messages will end up there. This is important as graphical output won't work once FreeBSD is booted using LinuxBIOS and ADLO.