Building a chain boot system from the menuconfig2 branch

Chain booting is described on the ChainBooting page. Here's how to build a system using it. This page assumes that you've already got a working Balloon build environment. There are details of how to achieve this on the SoftwareBuilding page. Note that many configuration options can now be chosen by menu instead of by editing makefiles.

First, check out the menuconfig2 branch:

svn co svn+ssh://<you>

Note that the file structure checked out of svn relies on a certain number of symbolic links. For that reason, we recommend checking it out using svn on Linux. Using a tool like TortoiseSVN on Windows can lead to the symbolic links becoming short nonsense files, which breaks things. One symptom is that chain booting won't work.

You may need to install the following Debian package:

apt-get install linux-libc-dev-armel-cross


make menuconfig

to get the configuration menu.

From the options, choose the following. If an option isn't mentioned here, it's not critical for getting a working system:

Now build the lot:



Program bootldr (from build/bootldr/ into NOR using JTAG or load bootldr at existing bootldr prompt. Program zImageInitrd (fron build/kernel) into NOR using load kernel at bootldr prompt. boot at bootldr prompt

Username is root, no password.

Mount the boot partition as a YAFFS partition (the default):

mount /mnt/boot

and put your boot kernel into it:

cd /mnt/boot

and put zImageBoot there from wherever you have it - ZMODEM over the console serial port can be convenient.

When loaded, create a symlink to it:

ln -s zImageBoot vmlinuz

Now mount the root filesystem (YAFFS is the default):

mount /mnt/root

Somehow shovel your rootfs into this. There are many ways of doing this. If your Balloon setup has a USB host connector, use a USB stick or similar. Mine doesn't, so I use the procedure in Balloon3SingleSidedRootFS.

Now you can exit and reboot the system:


Press space bar to get into bootldr prompt very quickly!

Configure the bootldr for chain booting:

set bootscript=chainboot_nand
params save

(note that bootldr params are now saved in NOR Flash rather than NAND, so bootldr doesn't need to know anything about NAND filesystems).

Boot the system:


and chain booting should happen.

To get into the recovery kernel, go to the bootldr prompt (press space immediately after power-up) and do

set bootscript=exit
boot flash

Balloonboard: SoftwareBuilding/Menuconfig2 (last edited 2011-03-10 11:42:52 by ChrisJones)