BBB: Where to find the MLO and u-boot.img file in BBB?

I am using beaglebone black. I am following Exploring BeagleBone Book by Derek Mollow. As per book and online forum, The SD card /eMMC should have two partitions
p1 : FAT32 for containing the MLO, u-boot.img and uEnv.txt file
p2: ext4 type for root file system

In contrary, I download the latest image flash the SD card,
It only created one partition and I am unable to see the MLO, u-boot.img and uEnv.txt file in /boot/uboot/ directory. I can see bbb-uEnv.txt file in root directory.

So my question is, why the latest image did not create two partitions and where are the binaries of MLO and u-boot.img?

Hi @hmluqman , the am335x’s boot rom used on the BeagleBone Black supports many different boot methods. The first edition of Derek’s book goes over the common fat32 boot partition method. We eventually switched to using am335x’s “raw boot” mode, to cleanup the partition layout and help hide MLO/u-boot.img as some new users tended to accidentally deleted those files and return the board as “broken”…

Today, you’ll find, MLO and u-boot.img in the first “1MB” of the media, in the “hole” at the start of the partition. I don’t remember if Derek talks about this in his 2nd edition, i don’t see it on my bookcase this morning…


1 Like

@RobertCNelson Thanks for the answer. Basically, I am building custom Linux image using Yocto, so is it still right to put u-boot.img, MLO and uEnv.txt in p1 (FAT32 type) and root filesystem in p2 (ext4)?
in eMMC card, there is uEnv.txt file in /boot/ directory, should it not be be in the “hole” partition?

Hi @hmluqman for Yocto, stick uEnv.txt right next to MLO/u-boot.img in the fat partition…

Normally, this partition would be mounted as /boot/ thus your uEnv.txt would be at /boot/uEnv.txt