Gentoo on the Pandaboard and Pandaboard ES
Installing Gentoo in the Pandaboard is pretty simple if you're already a Gentoo user.
You need to use an SD card, at least of 2 GB of size. If you
are familar with the Gentoo Linux installation process, there is not much
To be able to install Gentoo, you'll need the following:
- An x86/amd64 based PC with Gentoo and an SD card reader on it
- A Pandaboard
- One SD card (2 GB is enough)
- A network connection
Preparing to install your Pandaboard
Before we start the installation process, we need to get/build a kernel and a bootloader
for the Pandaboard.
The Pandaboard doesn't have a NAND/flash device, so the bootloader (U-Boot) needs to be located
on the SD card, along with the kernel.
Emerging needed tools
For building the stuff needed to boot our Pandaboard, we need the following tools emerged
on the host system where we're going to build them.
sys-devel/crossdev - to create a crosscompiler
dev-embedded/u-boot-tools - to create a kernel image U-Boot can understand
sys-fs/dosfstools - to create FAT32 filesystems
Code Listing 3.1: Emerge needed tools
# emerge sys-devel/crossdev dev-embedded/u-boot-tools sys-fs/dosfstools
Build a crosscompiler
Code Listing 3.2: Building a crosscompiler
# crossdev -S armv7a-hardfloat-linux-gnueabi
Code Listing 3.3: Obtaining U-Boot
# wget ftp://ftp.denx.de/pub/u-boot/u-boot-latest.tar.bz2
# tar xjpf u-boot-latest.tar.bz2 && cd u-boot-*
Code Listing 3.4: Compiling U-Boot
# make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabi- omap4_panda_config
# make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabi-
Obtaining/Building a kernel
For booting the Pandaboard we need a kernel. The vanilla kernel.org isn't as tested
as the one used on Ubuntu. TI has decided to provide support to
Ubuntu, so we'll make sure we have all the fixes ubuntu gets by using their kernel.
Note: If the following link gives you a 404 not found error, download the latest .tar.gz file from
the precise distribution here:
Code Listing 3.5: Obtaining the kernel
# wget 'https://launchpad.net/ubuntu/+archive/primary/+files/linux-ti-omap4_3.2.0-1412.16.tar.gz'
# tar zxvf linux-ti-omap4_3.2.0-1412.16.tar.gz && cd ubuntu-precise
The default kernel config for this kernel version is really minimal, and doesn't have support for wifi or
accelerated graphics drivers. So i've decided to provide a basic kernel config.
Code Listing 3.6: Configuring the kernel
# wget http://dev.gentoo.org/~armin76/arm/pandaboard/kconfig -O .config
Code Listing 3.7: Cross-compiling the kernel
# make -j9 ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabi- uImage
Once it gets built we'll have a kernel image on arch/arm/boot/uImage.
SD card setup
OMAP-based systems need a special setup of the SD card to boot from it. For more information please
check this link.
Formatting the SD card
The following script will format your SD card accordingly, creating two partitions.
The first partition size is based on the size of the SD card itself, and it's formatted in vfat.
The second partition is the free space left on the card after the first partition, and it's formatted in ext4.
Code Listing 4.1: Formatting the SD card
# wget http://dev.gentoo.org/~armin76/arm/pandaboard/mkcard.sh
# bash mkcard.sh /dev/mmcblk0
Copying U-Boot, MLO and the kernel to the SD card
Now we'll mount the first partition on the card and copy the needed files
(the ones that we built before) to boot our Pandaboard.
Code Listing 4.2: Copying U-Boot and the kernel to the SD card
# mkdir /mnt/p1 ; mount /dev/mmcblk0p1 /mnt/p1
# cp u-boot-*/MLO /mnt/p1
# cp u-boot-*/u-boot.img /mnt/p1
# cp ubuntu-precise/arch/arm/boot/uImage /mnt/p1
The installation on this device is a bit different, and therefore easy, as we can't install Gentoo on it
by booting an installation environment. For installing Gentoo (and any other distro, really)
you need to put the SD card on your PC and prepare there the
What we'll have to do to setup our installation is:
- Extract stage3 to the 2nd partition of the SD card
- Extract portage snapshot (required to emerge things and ntp(see below))
- Setup fstab
- Setup root password
- Configure hostname and networking (optional, but recommended)
- Enable SSH access (optional, but recommended)
- Enable serial console access (optional, but recommended)
Here's some information about the stages.
- Architecture: arm
- Subarchitecture: armv7a
- CHOST: armv7a-hardfloat-linux-gnueabi
- Profile: default/linux/arm/10.0
We'll be using the new EABI, also called gnueabi. Also we'll use hardfloat.
That is armhf on Debian.
Therefore, we need an armv7a-hardfloat-linux-gnueabi stage3 for best performance, available under the
releases/arm/autobuilds directory in your favorite mirror. You need to grab an armv7a_hardfp stage3.
Optionally you can also grab a portage snapshot
Extracting a stage3
Mount the second partition of the SD card and extract the stage3 you downloaded.
Code Listing 5.1: Mounting the partition and extracting the stage3
# mkdir /mnt/p2
# mount /dev/mmcblk0p2 /mnt/p2
# tar xjpf stage3-armv7a_hardfp-20101118.tar.bz2 -C /mnt/p2
Extracting a portage snapshot (optional)
Code Listing 5.2: Extracting the snapshot
# tar xjpf portage-latest.tar.bz2 -C /mnt/p2/usr
Edit the /mnt/p2/etc/fstab file to look like this:
Code Listing 5.3: /mnt/p2/etc/fstab
# NOTE: If your BOOT partition is ReiserFS, add the notail option to opts.
/dev/mmcblk0p1 /boot vfat noauto,noatime 1 2
/dev/mmcblk0p2 / ext4 noatime 0 1
/dev/SWAP none swap sw 0 0
/dev/cdrom /mnt/cdrom auto noauto,ro 0 0
#/dev/fd0 /mnt/floppy auto noauto 0 0
Setting the default root password
This is the most important part of the installation. As without the root
password we won't be able to login!
For setting the password, we need to be able to run passwd. However that's
not possible since our PC can't run ARM binaries. Therefore we need to modify
the file that contains the passwords (/etc/shadow) inside the chroot,
so we can set a default root password.
Code Listing 5.4: Change the default root password
# openssl passwd -1
# nano -w /mnt/p2/etc/shadow
Setup hostname and networking
the network configuration chapter of the ARM handbook to configure the network.
One of the problems the pandaboard has, is that it doesn't have a battery
to save the clock time. To mitigate this, on Gentoo we have an option in our init
system called swclock which sets the date of the system upon boot from
a last modified date of a file.
Code Listing 5.5: Adding swclock to the startup
# ln -sf /etc/init.d/swclock /mnt/p2/etc/runlevels/boot
We remove hwclock from the startup because it sets the date
from the RTC, which is 2000-01-01 upon startup and overrides swclock's
Code Listing 5.6: Removing hwclock from the startup
# rm /mnt/p2/etc/runlevels/boot/hwclock
swclock uses the /lib/rc/cache/shutdowntime's modification time to set
the date, therefore we update it to have the current date and time.
Code Listing 5.7: Setting the correct date
# touch /mnt/p2/lib/rc/cache/shutdowntime
Although this doesn't fix the issue, at least helps to set a sane date and time.
Note: Consider using NTP, documented on the next chapter
Enabling SSH access (optional)
We can add sshd to the startup of our system so we can access our Pandaboard
Code Listing 5.8: Adding sshd to the startup
# ln -sf /etc/init.d/sshd /mnt/p2/etc/runlevels/default
Enabling serial console access (optional)
By default the ttyS0 port is configured at 9600 bps. However, almost all of the
ARM devices run the serial port at 115200 bps. Also, in the case of the Pandaboard,
the port is ttyO2 instead of the normal ttyS0.
So this should be added to the /etc/inittab file:
Code Listing 5.9: Configuring serial console
# nano -w /mnt/p2/etc/inittab
s0:12345:respawn:/sbin/agetty 115200 ttyO2 vt100
Finishing the installation
Let's unmount the SD card
Code Listing 5.10: Unmounting the SD card
# umount /mnt/p1 /mnt/p2
This is pretty much all of the installation.
I'd highly recommend that you read all the recommendations of the handbook.
Booting up our new system
Once you have the card ready, put it into the Pandaboard... and you should be able to boot it.
One of the problems of the Pandaboard is that it doesn't save the date because it doesn't have
a battery for the clock.
After logging into our new Gentoo on Pandaboard installation, I'd recommend setting a date and
emerging net-misc/ntp to keep the clock up-to-date. Also it's recommended to put both
ntp-client and ntpd to boot on startup, so you get a proper date setup.
However, keep in mind that NTP requires a network connection and a NTP server being reachable,
either on the local network or on the Internet.
Code Listing 7.1: Emerging net-misc/ntp
# emerge net-misc/ntp
# rc-update add ntpd default
# rc-update add ntp-client default
# /etc/init.d/ntp-client start
# /etc/init.d/ntpd start
The Pandaboard has integrated hardware that needs either a driver, firmware or tools to
work. Making work such hardware is documented on the following page
You may find more documentation about the device itself and Linux-related at
the following links:
pandaboard.org for providing me a Pandaboard to document and
support Gentoo on it
- My coworker Jordi Inglés, who gave me an 8 GB SDHC for this project
- Siarhei Siamashka (ssvb) for giving helpful hints
- Michael Majchrowicz for checking the doc in the Pandaboard ES
The contents of this document, unless otherwise expressly stated, are licensed under the CC-BY-SA-2.5 license. The Gentoo Name and Logo Usage Guidelines apply.