Download the latest version of u-Boot and extract the files to a working folder:
wget ftp://ftp.denx.de/pub/u-boot/u-boot-latest.tar.bz2 tar -xjf u-boot-latest.tar.bz2 cd u-boot-2014.01
Cross Compile u-Boot using the GuruPlug configuration:
make CROSS_COMPILE=arm-linux-gnueabi- distclean make CROSS_COMPILE=arm-linux-gnueabi- guruplug_config make CROSS_COMPILE=arm-linux-gnueabi- u-boot.kwb
Compiling should conclude with output similar to that below.
Preparing kirkwood boot image to boot from nand Nand ECC mode = default Nand page size = 0x800 Image Type: Kirkwood Boot from NAND Flash Image Data Size: 250496 Bytes = 244.62 kB = 0.24 MB Load Address: 00600000 Entry Point: 00600000
It is always a good idea to load your newly compiled version of u-Boot into RAM first and test it.
setenv ipaddr 192.168.0.250 setenv serverip 192.168.0.251 tftp 0x800000 u-boot.kwb go 0x800200
When you are confident and ready to take the plunge, you can burn u-Boot to flash using:
setenv ipaddr 192.168.0.250 setenv serverip 192.168.0.251 tftp 0x6400000 u-boot.kwb nand erase 0x0 0x100000 nand write.e 0x6400000 0x0 0x100000
Upon reboot, you should be greeted with your new u-Boot. Congratulations.
U-Boot 2014.01 (Mar 25 2014 - 04:50:06) Marvell-GuruPlug SoC: Kirkwood 88F6281_A1 DRAM: 512 MiB WARNING: Caches not enabled NAND: 512 MiB *** Warning - bad CRC, using default environment In: serial Out: serial Err: serial Net: egiga0 Warning: failed to set MAC address , egiga1 Warning: failed to set MAC address 88E1121 Initialized on egiga0 88E1121 Initialized on egiga1 Hit any key to stop autoboot: 0 Marvell>>