Das U-Boot, or just U-Boot for short, is an open source firmware/bootloader for embedded PowerPC, ARM and other architectures including AVR32.
The latest u-boot can be found in the AVR32 Custodian tree at denx.de. To clone it:
git clone git://www.denx.de/git/u-boot-avr32.gitThis will create the directory
u-boot-avr32 with a clone of the repository and a checked out working copy of the master branch. To switch to a different branch, e.g. "avr32-fixes" (which is not always present), use the "git checkout" command like this:
git checkout avr32-fixesNote that NGW100 support has been merged into mainline, so there's no need to use the ngw-board branch anymore. In fact, the ngw-board branch has been deleted since it didn't contain any commits that weren't also in "master".
For more information about git, please see the official documentation.
There's also a page with UbootPatches at this site, containing AVR32-specific versions of u-boot with additional features not found in mainline yet.
There is a FlashUpgrade tool made to upgrade U-Boot even when it is running from internal flash. The FlashUpgrade tool works by running from SDRAM after loaded by your current U-Boot, and after that it can erase and program the current U-Boot to a newer version. You can also embed other bootloaders than U-Boot into the FlashUpgrade tool.
For more information about running u-boot on UC3 chips, please see the UBootOnUC3 page.
Visit the "overclocking" section here