The original u-boot.bin for the BBB boots the kernel with the MPU frequency set to 520 MHz. I'm running a non-Linux kernel which currently has some difficulties changing the frequency to 1 GHz. I saw a patch go into U-Boot very recently (like a couple of days ago) which appears to teach it to recognize the BBB's processor and increase the MPU frequency to 1 GHz before starting the kernel, so I would very much like to replace the u-boot.bin I currently use with a new one that can do this.
Unfortunately I'm also not in a position to compile a new U-Boot from source so I'd like to find a new, pre-compiled u-boot.bin which has this patch. Does anyone know where I could find one of these?
Right at the bottom of that page it describes how to build from stock. And just above that, is all the patches made (I’m not sure if they have been merged in yet)
They have not been merged yet (and there might need to be some more changes required for the general parts of the patch series). Also note, you want u-boot.img not u-boot.bin and you’ll need to replace MLO as that’s where the clock parts end up. As someone else posted, there’s a link on how to build U-Boot. Just follow that general instructions, but use current u-boot git, and grab the patches you need from http://patchwork.ozlabs.org/project/uboot/list/
mostly, that page was meant for showing students a recipe for how to
build a functional u-boot.img for the BBB in a standalone context --
seems to work -- and as grist for discussion in terms of walking
through the patches and arguing about the purpose of each patch and
giving students an exercise of applying a patch or two and rebuilding.
i recall tom rini gave a quick overview of the value of each patch
(can't lay hands on the link for that, dang), and i'll take a look at
the ozlabs link tom mentions to see if i can update that page at all.
feedback welcome. as i said, it's not meant so much for reference as
for showing students how to build a simple, functional u-boot.
rday
p.s. i did add a final section to that page since its creation:
Hi Robert,
I took a look at your step by step guide for building u-boot, but I did not have much success. I am trying to build a stock image of u-boot which will load Angstrom on the eMMC. Building u-boot from the most recent source in the git repository did not produce a u-boot.img/MLO combination that could successfully boot angstrom from the eMMC (used am335x_boneblack_config). Do you have any suggestions? I would really like to get this working so that I can update some control register bits that are only available in a secure privileged mode - the current Angstrom distribution for the BeagleBone Black does not have the L1NEON bit set (which allows the NEON unit to access the L1 cache).
-Aaron