Modify u-boot in Yocto

[AlbertT]

Hello,

I am starting to use Yocto but I have a lots of difficulties to understand how it works. Let's say I just want to modify u-boot, how should I proceed ?

I am following the Tasks which are published on this forum. I have found sources of u-boot extracted in build/tmp/work/imx6qsabresd-poky-linux-gnueabi and modified this files but when I recompile nothing happens.

Thanks !

[marianodo]

Hi all. I'm Mariano Dominguez, Sorry that i'm re-open this question but i have the same problem and i  don't know how to resolve it. I'm using Yocto 1.4 for I.MX 53. I'm compiling with bitbake. I want to make a change into u-boot-dey but then i can't re-compile. I put "bitbake u-boot-dey" but nothing happends, then i tried with "bitbake -f u-boot-dey", but still not working and finally i tried with "bitbake -c clean u-boot-dey" and then "bitbake u-boot-dey", this worked but when i put the flag "-c clean" all my changes was delete and then when compile, it genereted the new image but without my changes. How can i re-compile?

Thanks

Mariano

[OtavioSalvador]

When I hack U-Boot I never do it inside Yocto build system but I use a toolchain (which is build using Yocto) for it.

For toolchain build:

$: bitbake meta-toolchain

Using this you can build U-Boot byhand.

Once you did the need changes, considering you're making a product, you would do:

* make a company/product layer

* add a board file which is based on your development platform

* add a bbappend to apply the need patch for it

I hope it is helpful.

[AlbertT]

Yep totally ! I usually compile by myself, but I wanted to see the possibilities of Yocto. Thanks !

[eladyosef]

Hi all, sorry for re-asking this question but I'm trying to automate the my build using Yocto and also have the ability to replace SDK versions easily.

I have u-boot.patch file and bbappend that adds the patch to SRC_URI.

the bbappend file is located under my_layer/recipes/recipes-kernel/u-boot/

but for some reason bitbake -f u-boot does not take my changes.

I also tested my bbappend by over-writting the "do_listtasks" to echo to console.

when I place the bbappend in the same folder with the u-boot.bb it works

Can anyone assist?

Thanks

Elad

[OtavioSalvador]

It all depends on the u-boot recipe you are going to use.

In meta-fsl-arm we have:

• u-boot-imx
• u-boot-fslc

OE-Core/Poky has:

• u-boot

I think you intend to bbappend u-boot-fslc.

[LeonardoSandova]

Check this document: https://community.freescale.com/docs/DOC-95003

Leo

[saikumarmails]

The link is broken, can you share a working one? Thanks.

[AlbertT]

Thanks Leo ! I tried this procedure with the command bitbake -c u-boot but it didn't worked. Since there are multiple directories u-boot I am not sure I am modifying the good one.

[LeonardoSandova]

Well, in that case do a –c clean, then –c compile, then compare timestamps on all u-boot folders. Do you work on the folder with latest timestamps.

Leo

[AlbertT]

Ok thanks I will try this one. !