topic Re: Changing the Kernel configuration for i.MX6 SABRE in i.MX Processors

Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Thu, 24 Sep 2015 15:56:17 GMT

I’m trying to change the default Kernel to include PCIe, but I’ve been having real problems trying to change the configuration used to build the kernel.

I can build a default kernel using the following steps (I’m using branch imx-3.10.53-1.1.0_ga)

$ mkdir fsl-release-bsp

$ cd fsl-release-bsp

$ repo init -u git://git.freescale.com/imx/fsl-arm-yocto-bsp.git -b imx-3.10.53-1.1.0_ga

$ repo sync

$ MACHINE=imx6qsabresd source fsl-setup-release.sh -b build-x11 -e x11

$ bitbake core-image-base

This image works fine. I can power up my Sabre platform.

But I now want to change the Kernel configuration to include PCIe, but it seems that the documented way (see “Task #5 - Kernel - The complete step by step to change the kernel configuration”) doesn’t work for me. Here are the steps from the document.

$ bitbake -c menuconfig linux-imx

(change anything)

$ cp tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.0.35-r33.10/git/.config ../sources/meta-fsl-arm/recipes-kernel/linux/linux-imx-3.0.35/mx6/defconfig

$ bitbake -c cleansstate linux-imx

$ bitbake fsl-image-gui

But I don’t have the correct paths for the “cp” command. My .config file is actually located in

./tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.10.53-r0/git/.config

So I would expect to find a matching folder in ../sources, but I don’t have a “../sources/meta-fsl-arm/recipes-kernel/linux/linux-imx-3.0.35” directory ;-(

The only directories I have at this level are

linux-fslc linux-imx-2.6.35.3 linux-imx.inc linux-imx-rt_3.10.17.bb

linux-fslc_3.14.bb linux-imx_2.6.35.3.bb linux-imx-mfgtool-3.10.17 linux-mfgtool.inc

linux-fslc.inc linux-imx-3.10.17 linux-imx-mfgtool_3.10.17.bb linux-timesys-3.0.15

linux-imx linux-imx_3.10.17.bb linux-imx-rt-3.10.17 linux-timesys_3.0.15.bb

And I think (by looking at each sub-directory) that…

Linux-imx-2.6.35.3 is used for mx5, imx23evk, imx28evk
Linux-imx-3.10.17 is used for imx6

So I’ve tried copying .config to linux-imx-3.10.17/imx/defconfig and created new directories for linux-imx-3.10.53/imx/defconfig. Then I run

$ bitbake -c cleansstate linux-imx

$ bitbake linux-imx

Then I program my SD card and try to power up and test my PCIe changes. But while it does boot up, none of my Kernel changes are present. I test this by using lspci and also the following command

$ cat /proc/config.gz | gunzip | grep –i pci

I’ve looked at other pages and it seems that I’m not the only one having problems, eg

https://community.freescale.com/thread/360368

https://community.freescale.com/thread/372003

https://community.freescale.com/message/563729#563729

https://community.freescale.com/docs/DOC-95045

https://community.freescale.com/docs/DOC-100847

The only way I found to change my Kernel that works is to run the following commands in this particular order.

$ bitbake linux-imx -c cleansstate
$ bitbake linux-imx -c menuconfig

(change anything)

$ bitbake linux-imx

The cleansstate removes …/3.10.53-r0/git/.config (and a lot of others files).
Then menuconfig populates …/3.10.53-r0/git before running the terminal to allow changes.
The build process picks up the changed …/3.10.53-r0/git/.config and builds the Kernel.

While this system works I realize that I’m changing a file in the ./tmp directory, so it will be lost when I clean my build. I guess the advantage of copying it to the ../source directory is that I could then have my own git branch and keep track of my changes.

So I would like to know what exactly my “copy” command should be, eg

$ cp tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.10.53-r0/git/.config

Any help on changing the Kernel configurations correctly would be greatly appreciated.

Cheers

Chris

Re: Changing the Kernel configuration for i.MX6 SABRE

gusarambula — Tue, 29 Sep 2015 19:49:40 GMT

Hello Chris Hossack,

You are not alone on this, as you pointed out, in part because Yocto is more a means of distribution of customized images (like BSPs) than a development tool. Yocto does not have a way to track changes on the source code so I would recommend downloading the kernel source code and working there building with the toolchain manually and once the necessary changes are ready writing a recipe that will apply these changes.

That being said I have also been unable to find the source for 3.10.53 inside the recipes-kernel folder. I’ll look for more information on what could be the reason for that.

Re: Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Wed, 30 Sep 2015 07:55:07 GMT

hi,

thank you for your reply. At the moment I'm just looking at evaluating the imx6 platform and I just need to prove I can build my PCI drivers on the target ( Building a Kernel driver on imx6 sabre target. ) and run some hardware correctly. But I guess I will have to read how to create my own recipes. I just wanted to know what I was missing when I followed the above method from the documentation.

cheers

Chris

Re: Changing the Kernel configuration for i.MX6 SABRE

saurabh206 — Wed, 30 Sep 2015 08:19:15 GMT

Hi Chris

You can use Yocto BSP setup for Rootfs, kernel and u-boot generation.

You can build kernel and u-boot separately using meta-toolchail

linux-2.6-imx.git - Freescale i.MX Linux Tree

You can download the kernel from above like, build the kernel manually and update the zImage or uImage.

Once the all modification is completed you can generate patches and use these patched with yocto recipe.

Thanks

Saurabh

Re: Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Wed, 30 Sep 2015 08:43:24 GMT

hi Sarurabh,

that sounds easy.. once you have done it a couple of times ;-)

But for a first time newbie are there any step by step instructions on how to do all of that?

I can find snippets for different bits of this process, but rather than bashing my head against a wall for the next couple of days it would be really nice for somebody who knows what they are doing to generate a newbie guide.

cheers

Chris

Re: Changing the Kernel configuration for i.MX6 SABRE

saurabh206 — Wed, 30 Sep 2015 08:52:57 GMT

Hi Chris,

You can look https://community.freescale.com/servlet/JiveServlet/previewBody/95096-102-10-7847/yocto_tutorial.pdf

Thanks

Saurabh

Re: Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Fri, 02 Oct 2015 08:35:35 GMT

hi Saurabh,

thank you. This looks very interesting. I will read this and give it a go. I'll get back to you next week.

cheers

Chris

Re: Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Wed, 07 Oct 2015 09:58:45 GMT

Hi,

So after getting some very good responses I decided to create my own layer and change the kernel configurations the correct way (well, I think so anyway…)

So repeating my initial steps I create a image based branch imx-3.10.53-1.1.0_ga.

$ mkdir fsl-release-bsp-3-10-53

$ cd fsl-release-bsp-3-10-53

$ repo init -u git://git.freescale.com/imx/fsl-arm-yocto-bsp.git -b imx-3.10.53-1.1.0_ga

$ repo sync

$ MACHINE=imx6qsabresd source fsl-setup-release.sh -b build-x11 -e x11

$ bitbake core-image-base

This image works fine. I can power up my Sabre platform.

I now create my new layer called meta-fsl-pci

cd ../source

$ yocto-layer create fsl-pci

Please enter the layer priority you'd like to use for the layer: [default: 6]

Would you like to have an example recipe created? (y/n) [default: n] y

Please enter the name you'd like to use for your example recipe: [default: example]

Would you like to have an example bbappend file created? (y/n) [default: n] y

Please enter the name you'd like to use for your bbappend file: [default: example]

Please enter the version number you'd like to use for your bbappend file (this should match the recipe you're appending to): [default: 0.1]

New layer created in meta-fsl-pci.

Don't forget to add it to your BBLAYERS (for details see meta-fsl-pci\README).

cd ../build-x11

I ‘m not sure why the magic number 6!! I want my layer to have the highest priority, so why not make it 99?
Also since I’m not adding any example app to the RFS I don’t think I need the example recipe or bbapend file.

Any comments?

I then update ./conf/bblayers.conf with my new layer.

BBLAYERS += " ${BSPDIR}/sources/meta-fsl-bsp-release/imx/meta-fsl-demos "

BBLAYERS += " ${BSPDIR}/sources/meta-fsl-pci "

BBLAYERS += " ${BSPDIR}/sources/meta-browser "

I verify this bit has worked by using the following command

bitbake-layers show-layers

layer path priority

==========================================================================

meta /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/poky/meta 5

meta-yocto /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/poky/meta-yocto 5

meta-oe /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-openembedded/meta-oe 6

meta-fsl-arm /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-fsl-arm 5

meta-fsl-arm-extra /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-fsl-arm-extra 4

meta-fsl-demos /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-fsl-demos 4

meta-fsl-arm /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-fsl-bsp-release/imx/meta-fsl-arm 0

meta-fsl-demos /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-fsl-bsp-release/imx/meta-fsl-demos 0

meta-fsl-pci /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-fsl-pci 6 <-- Here's my layer

meta-browser /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-browser 7

meta-gnome /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-openembedded/meta-gnome 7

meta-networking /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-openembedded/meta-networking 5

meta-ruby /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-openembedded/meta-ruby 7

meta-qt5 /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-qt5 7

meta-fsl-qt5 /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-fsl-bsp-release/imx/meta-fsl-qt5 0

meta-fsl-bluez /mnt/data/imx6/fsl-release-bsp-3-10-53/sources/meta-fsl-bsp-release/imx/meta-fsl-bluez 8

I now create a layer directory structure to support my PCI modifications to the kernel:

mkdir -p ../sources/meta-fsl-pci/recipes-kernel/linux/linux-imx

I now create my linux-imx_3.10.17.bbappend that matches the path in meta-fsl-arm, eg

ls ../sources/meta-fsl-arm/recipes-kernel/linux/linux-imx-3.10.17

cat ../sources/meta-fsl-pci/recipes-kernel/linux/linux-imx_3.10.17.bbappend

FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"

SRC_URI += "file://pci.cfg"

I think "${THISDIR}/${PN}:" expands out to ../sources/meta-fsl-pci/recipes-kernel/linux/linux-imx

I now create my pci.cfg file.

bitbake linux-imx -c cleansstate

bitbake linux-imx -c menuconfig

bitbake linux-imx -c diffconfig

Config fragment has been dumped into:

/mnt/data/imx6/fsl-release-bsp-3-10-53/build-x11/tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.10.53-r0/fragment.cfg

NOTE: Tasks Summary: Attempted 1 tasks of which 0 didn't need to be rerun and all succeeded.

Then copy to pci.cfg

cp /mnt/data/imx6/fsl-release-bsp-3-10-53/build-x11/tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.10.53-r0/fragment.cfg ../sources/meta-fsl-pci/recipes-kernel/linux/linux-imx/pci.cfg

I then clean and rebuild

bitbake linux-imx -c cleansstate (do I need to do this or is Yocoto clever enough)

bitbake linux-imx

But when I power up with the new image my PCI configurations changes are missing ;-(

Can anybody please tell me what I'm doing wrong.

Cheers

Chris

Re: Changing the Kernel configuration for i.MX6 SABRE

matt0308 — Tue, 13 Oct 2015 08:32:03 GMT

Hi Chris,

I am suffering the same issue now. No matter where the defconfig/.cfig is located. Kernel .config file has never updated according to defconfig/.cfg with command "bitbake -c compile -f linux-imx". Do you solve the problem?

I also find some information from Yocto Project Linux Kernel Development Manual . But these steps don't work on my environment either.

Cheers,

Matt

Re: Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Tue, 13 Oct 2015 10:12:32 GMT

Hi,

I haven't solved this problem yet either ;-(

I've read most of the manuals that describe how to do this, but with no luck. I'm sure its easy once you know how, but nobody has told me.

I'm still working on this and I'll post my answer, if I find one.

If you manage to work it out please let me know.

cheers

Chris

Re: Changing the Kernel configuration for i.MX6 SABRE

saurabh206 — Tue, 13 Oct 2015 12:40:07 GMT

Hi Chris

You have to create your custom layer. Create your patched with respect to kernel.

If you have added your custom defconfig file name like "mydefconfig"

than add following to your local.config file.

FSL_KERNEL_DEFCONFIG = "mydefconfig"

Thanks

Saurabh

Re: Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Tue, 13 Oct 2015 13:50:42 GMT

hi Saurabh,

thank you for your answer. I thought I had to create a .cfg file which then updates the deconfig (which seems to be copied from imx_v7_defconfig as describe in linux-imx_3.10.53.bb), which is then used to generate .config with my changes.

Originally I created a linux-imx_3.10.17.bbappend (see previous comment) but nothing happened. I have found that if I rename this to linux-imx_3.10.53 my pci.cfg is copied to the work directory (next to the defconfig ((copied from imx_v7_defconfig)) but still the .config are missing my changes ;-(

So should I be using a mydefconfig or a .cfg? and what is the difference?

thank you

Chris

Re: Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Tue, 13 Oct 2015 19:12:40 GMT

hi,

so by changing the name of

../sources/meta-fsl-pci/recipes-kernel/linux/linux-imx_3.10.17.bbappend

../sources/meta-fsl-pci/recipes-kernel/linux/linux-imx_3.10.53.bbappend

which reflects the actual kernel I'm building, I now see my pci.cfg file here next to a defconfig

./tmp/work/imx6sabresd-poky-linux-gnueabi/linux-imx/3.10.53-ro/pci.cfg

But my changes are still missing from (after running cleansstate and menuconfig)

./tmp/work/imx6sabresd-poky-linux-gnueabi/linux-imx/3.10.53-ro/git/.config

So after some more searching I found the following link which suggests the .cfg is broken for freescale imx.Kernel config fragments are not applied

Bruce Ashfield suggests a work around and a fix for Yocto 1.7. I've tried the suggestion, eg

FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"

inherit kernel

COMPATIBLE_MACHINE = "(mx6)"

SRC_URI += "file://pci.cfg"

SRCREV_machine = "${SRCREV}"

but that didn't work either, and I'm already using Fido 1.8

The links are a bit old so I'm hoping I'm still doing something silly. Does anybody have an answer?

cheers

Chris

Re: Changing the Kernel configuration for i.MX6 SABRE

matt0308 — Wed, 14 Oct 2015 04:09:12 GMT

Hi Saurabh,

I'd followed your suggestion to do the test but fail. Just wondering where to put the "mydefconfig"? Currently, I put "mydefconfig" in $(yocto)/sources/meta-mylayer/recipes-linux/linux/linux-imx-3.10.53/. Should I move it to somewhere else?

Cheers,

Matt

Re: Changing the Kernel configuration for i.MX6 SABRE

saurabh206 — Wed, 14 Oct 2015 05:21:42 GMT

Hi Shiuan

You must first generate patch for your defconfig.

Put that patch in your layer.

Run Bitbake linux-imx.

Verify your defconfig is available in yocto build kernel. If yes than you need to update the local.config file.

and build again.

Re: Changing the Kernel configuration for i.MX6 SABRE

matt0308 — Wed, 14 Oct 2015 06:01:20 GMT

Hi Saurabh,

Thanks for your information, I did generate defconfig/mytest.cfg, put it into my layer and run "bitbake -c compile -f linux-imx" again. But the defconfig is not copy to git/.config. Where I also observed that mytest.cfg and defconfig are all copy to the working directory. I can patch mytest.cfg manually by "scripts/kconfig/merge_config.sh", but Yocto didn't patch anything.

BR,

Matthew

Re: Changing the Kernel configuration for i.MX6 SABRE

saurabh206 — Wed, 14 Oct 2015 06:16:49 GMT

Hi matthew,

Can you please confirm that your defconfig file is available in .git/arch/arm/configs/mydefconfig.

Re: Changing the Kernel configuration for i.MX6 SABRE

matt0308 — Wed, 14 Oct 2015 06:50:18 GMT

Hi Saurabh,

defconfig didn't copy to .git/arch/arm/configs/mydefconfig. After "bitbake -c compile -f linux-imx", ${S}/../defconfig is replaced by imx_v7_defconfig which is instructed by the following code snippet in sources/meta-fsl-bsp-release/imx/meta-fsl-arm/recipes-kernel/linux/linux-imx_3.10.53.bb. I wonder if I have to add some code snippet, like "do_configure_prepend()", to my linux-imx_3.10.53.bbappend.

do_configure_prepend() {

# copy latest defconfig for imx_v7_defoonfig to use

cp ${S}/arch/arm/configs/imx_v7_defconfig ${S}/.config

cp ${S}/arch/arm/configs/imx_v7_defconfig ${S}/../defconfig

}

Cheers,

Matt

Re: Changing the Kernel configuration for i.MX6 SABRE

maxmustermann — Fri, 16 Oct 2015 10:43:18 GMT

If you want some *robust* tool, which is also good for development, go for ptxdist.

Anyways, why are you using such an ancient kernel ?

Re: Changing the Kernel configuration for i.MX6 SABRE

chrishossack — Fri, 16 Oct 2015 15:02:54 GMT

Hi,

we're using the fsl layers that contain the device trees, drivers, tweaks, for the sabre platform. I'm not an expect on Kernels, so I'm just using the code freescale have tested with their boards. It's a bit of a cop out, but I don't think changing the kernel will solve my bitbake issues ;-(

cheers

Chris