How to enable FSBL customization in petalinux

[dnovick]

So, I'm getting used to Petalinux, and understand how to patch things like the linux kernel and u-boot.

However, I also need to customzie the FSBL build. For example, I want to add some more debug messages, turn on debug logging (which depends on a #define), and also do a debug build.

On the first two items, I had hoped that it would be a similar process as with the kernel and u-boot...i.e. make code changes in the git clone, create the patches, make changes to the appropriate bbappend file, yada yada.

However, I can't seem to do this with the fsbl, as unless I'm missing something, it doesn't use a local git repository. It appears to fetch the files...but not in a way that allows patching.

How do I 1) patch the source code to my liking and 2) Actually build in debug mode?

I know I could always create an FSBL in the Xilinx SDK, shuttle it over to my images directory, and petalinx-image against it...but it seems like petalinux should allow me to do as I describe. If I'm going to use petalinux, I'd prefer to use it for everything.

In fact as far as building in debug mode, I'm not sure exactly how to do that for Linux or u-boot. Is this possible within petalinux? If so, how?

Thanks,

Dave

[umamahe]

Please check whether any of the below Answer Record is useful for you

https://www.xilinx.com/support/answers/66853.html 

https://www.xilinx.com/support/answers/68057.html

[dnovick]

Ummmm....I'm not sure these are pointing to what you intended.

The first one seems to point to nowhere, as I end up at the support home page. The second are the release notes for petalinux 2016.3. 

Is that what you meant to do? Am I missing something?

Dave

[gavenant]

I have the exact same issue with the inconsistency.

You can use the "older" method:  Creating a New Zynq FSBL.

And modify the source there and build.

Then add it to your boot image using: 

petalinux-package  --boot --u-boot --fsbl directory/to/fsbl.elf 

You'd probably need to add the FSBL as an "application" to allow it to compile with the rest of the project - a bit of of a manual process. Hope it helps.

[debrajr]

You can create the customized FSBL in SDK and then copy it over to the images/linux folder of Petalinux and run the petalinux-package command
OR
Just use Bootgen to generate the BOOT.BIN file.

[sherman_hsu]

Hi

If your Petalinux equal or later than 2017.1, the following solution should work for you

Working with a user space Yocto layer-How to patch FSBL in v2017.1 PetaLinux Project

I have worked with this solution on Petalinux 2017.2

Regards,

Sherman 

[ronnywebers]

thanks @sherman_hsu, that's a great tip!

I'm just wondering how to create such a patch file.

Let's say I want to enable the debug info output of the FSBL on the COM port. In SDK, this could be done as follows : 

• open fsbl_debug.h
• add #define FSBL_DEBUG_INFO    1

Now if I understand you correctly, this can be somehow done from Petalinux too, using some patch file. 

Now I'm wondering how to create such patch file?

Also, can the actual FSBL source be seen somewhere in a petalinux project? Like in the build folder?

[jrhtech]

I haven't worked with the FSBL very much in the Yocto builds but you can find the source after building in the build dir, something like this:

build/tmp/work/zcu102_zynqmpnapa-poky-linux/fsbl/2017.2+gitAUTOINC+122565ec40-r0/git/lib/sw_apps/zynq_fsbl/src

and it gets the source from, https://github.com/Xilinx/embeddedsw.git.  the rule is in meta-xilinx-tools/recipes-bsp/fsbl

The other way I used to do it was generate the build using the hdf and the hsi tool.  I'm not really sure where this source came from but once it was generated I could just manually modify it and build it with make.  It's probably better to figure out the Yocto method at this point.

jeff

[sandeepg]

Hi @ronnywebers,

Refer http://www.wiki.xilinx.com/PetaLinux+Yocto+Tips I have added some steps to enable the debugs in FSBL and PMUFW.

Also here the steps to create the git patch.

$ git clone https://github.xilinx.com/embeddedsw/embeddedsw.git
$ git checkout tags/xilinx-v2017.2
$ git branch myembsw_2017.2
$ git checkout myembsw_2017.2
$ vim lib/sw_apps/zynqmp_pmufw/src/xpfw_mod_em.c //Modify the source
$ git add lib/sw_apps/zynqmp_pmufw/src/xpfw_mod_em.c
$ git commit -s 
$ git format-patch -1

[vanmierlo]

@sandeepg,

I must be stupid, but I still don't get it. Just like the people above I want the FSBL to be more verbose. I cannot believe I have to create a patch file for that. A simple -DFSBL_DEBUG compiler flag should be enough. So using petalinux 2017.4 I tried:

$ mkdir -p <plnx-proj-root>/project-spec/meta-user/recipes-bsp/fsbl

I don't think I need a files dir,  but if I do, please explain.

$ vim <plnx-proj-root>/project-spec/meta-user/recipes-bsp/fsbl/fsbl_%.bbappend

#Enable appropriate FSBL debug flags
YAML_COMPILER_FLAGS_append = " -DFSBL_DEBUG"

 Why would this fail? It builds alright, but I get no verbose output.

[sandeepg]

Hi @vanmierlo,

After you enable the debug flags run this following commands. Refer http://www.wiki.xilinx.com/PetaLinux+Yocto+Tips 

$ petalinux-build -x mrproper
$ rm -rf <plnx-proj-root>/components/plnx_workspace
$ petalinux-build  

[stephenm]

You can just create a fsbl_%.bbappend and add the
YAML_COMPILER_FLAGS_append = "Insert compiler flag”

In a fsbl recipe in the recipes-bsp in your petalinux project.

Have you tried this? Does it work?

[vanmierlo]

Well, I had tried that and it seemed not to work. That was why I was asking here in the first place.

But now I see that it does work. I'm beginning to think that maybe the FSBL was writing to one of my other UARTs which are implemented in the PL.

Thanks for sticking with me.

[wicky_waka]

Just for enabling debug messages below procedure worked for me:

mkdir -p <plnx-proj-root>/project-spec/meta-user/recipes-bsp/fsbl
nano <plnx-proj-root>/project-spec/meta-user/recipes-bsp/fsbl/fsbl_%.bbappend

Then Add the following to the file:

#Enable appropriate FSBL debug flags  
YAML_COMPILER_FLAGS_append = " -DFSBL_DEBUG"

Now, do the following to build the new FSBL.

petalinux-build -x mrproper
rm -rf <plnx-proj-root>/components/plnx_workspace
petalinux-build

Now you can find the newly compiled fsbl in your images/linux directory. Now use the following command to make the BOOT.BIN file.

petalinux-package --boot --fsbl images/linux/zynq_fsbl.elf --fpga images/linux/<fpga>.bit --u-boot

Now copy the generated BOOT.BIN to the FAT partition of your SDCard and boot the board(ZedBoard for me) in SD-card boot mode.

For demonstration, I made a video tutorial you can watch it below:

[maju42]

Hi @stephenm @sandeepg @wicky_waka  ,

The debug flag as below is not working for me.

#Enable appropriate FSBL debug flags
YAML_COMPILER_FLAGS_append = " -DFSBL_DEBUG"

 I looked at http://www.wiki.xilinx.com/PetaLinux+Yocto+Tips, but did not find a similar flag. I am assuming the flag has been modified to:

#Add debug for FSBL
XSCTH_BUILD_DEBUG = "1"

Is this correct?

[sandeepg]

Hi @maju42 

There is not such flags called -DFSBL_DEBUG you need to fill this content with appropriate flags such as 

#Add debug for FSBL
XSCTH_BUILD_DEBUG = "1"

YAML_COMPILER_FLAGS_append = " -DXPS_BOARD_ZCU102 -DFSBL_PROT_BYPASS_EXCLUDE"

For more details refer https://github.com/Xilinx/embeddedsw/blob/master/lib/sw_apps/zynqmp_fsbl/src/xfsbl_config.h

Make sure you checkout the right release version in above link.

[vanmierlo]

---

@sandeepg wrote:

There is not such flags called -DFSBL_DEBUG

---

This is wrong as general as it is written here. This is exactly the right flag for Zynq.

But for ZynqMP things could be different.