[Buildroot] [BuildRoot] at91sam9x5ek_defconfig not booting

Thomas Petazzoni thomas.petazzoni at free-electrons.com
Thu Oct 12 20:01:11 UTC 2017


Hello,

On Thu, 12 Oct 2017 16:11:38 -0300, Alejandro Ariel Fachini wrote:

> following resulting files, I am using this buildroot tag; *2016.02-rc3*:

Why use this tag, which is old *and* is a release candidate and not a
final stable release ?

> I have to flash the device with windows where my Ubuntu VM runs.
> The flashing addresses aree found inside the script for flashing being:
> 
>    - 0x0 for atboostrap.bin
> 
> 
>    - 0x40000 for u-boot.bin
> 
> 
>    - 0x180000 for at91sam9x35ek.dtb
> 
> 
>    - 0x200000 for zImage
> 
> 
>    - 0x800000 for rootfs.ubi
> 
> This configuration won't boot KERNEL. System goes to u-boot> prompt and
> when i use:
> *bootz 0x22000000 - 0x21000000*

Those addresses (0x22000000 and 0x21000000) are addresses in RAM. You
have to load zImage from flash to RAM at 0x22000000 and
at91sam9x35ek.dtb from flash to RAM at 0x21000000 prior to issuing the
"bootz" command. "bootz" only starts the kernel. If you haven't loaded
the kernel and device tree before running bootz, it obviously cannot
work.

> So i have a set of questions may be related to my inexperience:
> 
> 1- In my Buildroots build on my Ubuntu enviroment, if the file
> *at91bootstrap.bin* is my ATbootstrap bootloader, what is the file
> *at91sam9x5ek-nandflashboot-uboot-3.8.bin*?

They are exactly identical:

$ md5sum at91bootstrap.bin at91sam9x5ek-nandflashboot-uboot-3.8.8.bin 
fef2c8c4cf8eef64e28488324b11f86b  at91bootstrap.bin
fef2c8c4cf8eef64e28488324b11f86b  at91sam9x5ek-nandflashboot-uboot-3.8.8.bin

> 2- What is the file *boot.bin*?

It's again the same thing:

fef2c8c4cf8eef64e28488324b11f86b  boot.bin

The bootloader must be named boot.bin when you're doing SD card based
boot, but that's not what you're doing here, so you don't care.

> 3-Where is the file with the U_BOOT enviroment variables, in the compiled
> Buildroot results?????

No such file is produced. Therefore, the U-Boot environment on flash is
empty. But the U-Boot binary embeds a default environment, which takes
precedence when there is no environment defined in flash.

> 4-I used "make at91sam9x5ek_defconfig", then "make". Does this means that
> the default configuration in these files are not working???

I believe they are working. Have you followed the instructions in
board/atmel/readme.txt ?

> 5- Where do i set for building the file with Uboot Environment Variables?

You don't need this for a basic build.

> 6- Do i need to apply patches to the newest Bootloader version?

No, it should work as-is.

> 7- How do i do to change UBI format to jffs2 for compiling? i know how to
> do it in buildroot's menuconfig, but environment variables still sets to
> UBI.

Just don't use JFFS2. UBI is the thing you want to use.

Once again, please follow the instructions in board/atmel/readme.txt,
this should get you running.

Also, I suggest that you go through Free Electrons training materials
(both slides [1] and labs [2] are available, and labs are done on an Atmel
SAMA5D3 Xplained, with has lots of similarities). This would help
giving you the background necessary.

[1] http://free-electrons.com/doc/training/embedded-linux/embedded-linux-slides.pdf
[2] http://free-electrons.com/doc/training/embedded-linux/embedded-linux-labs.pdf

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com



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