= Building U-Boot =


Note: this stub is to help with the LEON3 Qemu tutorial.  The following instructions built the image and were run on a Debian Sqeeze host.

Download the latest release of the [http://www.denx.de/wiki/U-Boot/WebHome universal boot loader] from [ftp://ftp.denx.de/pub/u-boot/u-boot-latest.tar.bz2 the ftp] or, you can check out the developer branch using git. 
 $ git clone git://git.denx.de/u-boot.git
 $ cd u-boot

Locate the board to build. For example, if you wanted to build u-boot for the leon3...
 u-boot$ grep -R "leon3"

Set the toolchain
 $ export CROSS_COMPILE=/opt/rtems-4.11/bin/sparc-rtems4.11-
Build the package with the following configure command:

  $ /configure --prefix=/tmp/g2/build
  $ make all install

where the prefix can be anything suitable for your machine. If configure fails with a missing LZO library check you have the lzo-devel package installed.

To make the floppy image follow the instructions in the Grub Wiki at http://grub.enbug.org/TestingOnX86. This script is adapted from the instructions:

 #! /bin/sh -x
 grub=/tmp/g2/build
 workspace=/tmp/g2
 mnt=$workspace/mnt/loop
 file=$workspace/rtems-boot.img
 export PATH=$grub/bin:$grub/sbin:$PATH
 mkdir -p $workspace
 cd $workspace
 grub-mkimage -o core.img _chain ls pc multiboot gpt fat boot reboot configfile cat help
 dd if=/dev/zero of=$file bs=512 count=2880
 /sbin/mkdosfs $file
 mkdir -p $mnt
 mount -o loop -t vfat $file $mnt
 mkdir -p $mnt/boot/grub
 cp $grub/lib/grub/i386-pc/boot.img core.img $grub/lib/grub/i386-pc/*.mod $mnt/boot/grub
 echo "configfile (hd0,0)/rtems-grub.cfg" > $mnt/boot/grub/grub.cfg
 echo '(fd0)' $file > tmp_device.map
 grub-setup -d $mnt/boot/grub -r '(fd0)' -m tmp_device.map '(fd0)'
 rm -f tmp_device.map
 umount $mnt