topic Re: issue: fdt_file gets changed after reboot in i.MX Processors

issue: fdt_file gets changed after reboot

Raxesh-Oriya — Wed, 11 Aug 2021 02:54:21 GMT

I have imx7ulpevk board with me and I have connected LCD display through MIPI interface. Default .dtb selected by u-boot is imx7ulp-evk.dtb but I want to use imx7ulp-evk-mipi.dtb as a default .dtb file. I made below change in board config file,

diff --git a/include/configs/mx7ulp_evk.h b/include/configs/mx7ulp_evk.h index cdc1a48..7ee1bf0 100644 --- a/include/configs/mx7ulp_evk.h +++ b/include/configs/mx7ulp_evk.h @@ -73,7 +73,7 @@ "console=ttyLP0\0" \ "fdt_high=0xffffffff\0" \ "initrd_high=0xffffffff\0" \ - "fdt_file=imx7ulp-evk.dtb\0" \ + "fdt_file=imx7ulp-evk-mipi.dtb\0" \ "fdt_addr=0x63000000\0" \ "boot_fdt=try\0" \ "earlycon=lpuart32,0x402D0010\0" \

with this change I generated an image, flashed on the SD card and booted up the board. Very first boot fdt_file variable gets updated with imx7ulp-evk-mipi.dtb but from next boot onwards fdt_file value gets back to imx7ulp-evk.dtb. I am unable understand what is happening, looks like variable gets overridden somehow.

U-boot version I am using is 2020.01+fslc+g76594fb.

Any lead on this?

Re: issue: fdt_file gets changed after reboot

nxf63675 — Wed, 11 Aug 2021 04:26:24 GMT

Hi Raxesh-Oriya,

For safe the changes that you made in u-boot you need to save the variables, by putting the command: saveenv on the console.

Hope this helps you.

Regards,

Israel.

Re: issue: fdt_file gets changed after reboot

Raxesh-Oriya — Wed, 11 Aug 2021 05:24:09 GMT

Hi nxf63675,

Thanks for your quick reply. Please elaborate on what do you exactly mean "putting command saveenv on console". I think that is required if I stop at u-boot console and modify fdt_file manually but that is not what I am doing instead I am making change in u-boot source code i.e. board configuration file. I do not want to do it manually.

Re: issue: fdt_file gets changed after reboot

nxf63675 — Thu, 12 Aug 2021 00:50:18 GMT

Hi @Raxesh-Oriya,

That's correct, I was meaning to stop in u-boot and write that command, but as you mention this is doing it manually, if you want to integrate this in u-boot you need to modify the "defconfig" of your device, please see on the link below:

https://source.codeaurora.org/external/imx/uboot-imx/tree/configs/mx7ulp_evk_defconfig?h=imx_v2020.04_5.4.70_2.3.0

In line 26 Modify and change the dtb that you are using,

CONFIG_DEFAULT_DEVICE_TREE="imx7ulp-evk-qspi"

Hope this helps you.

Regards,

Israel.

Re: issue: fdt_file gets changed after reboot

Raxesh-Oriya — Thu, 12 Aug 2021 03:19:00 GMT

Made following change,

diff --git a/configs/mx7ulp_evk_defconfig b/configs/mx7ulp_evk_defconfig index 3cf9015..00ddd18 100644 --- a/configs/mx7ulp_evk_defconfig +++ b/configs/mx7ulp_evk_defconfig @@ -17,7 +17,7 @@ CONFIG_CMD_I2C=y CONFIG_CMD_MMC=y CONFIG_CMD_FAT=y CONFIG_OF_CONTROL=y -CONFIG_DEFAULT_DEVICE_TREE="imx7ulp-evk" +CONFIG_DEFAULT_DEVICE_TREE="imx7ulp-evk-mipi" CONFIG_ENV_IS_IN_MMC=y CONFIG_SYS_RELOC_GD_ENV_ADDR=y CONFIG_DM=y

And this change leads to compilation error:

... ... ... | test -e arch/arm/dts/imx7ulp-evk-mipi.dtb || ( \ | echo >&2; \ | echo >&2 "Device Tree Source is not correctly specified."; \ | echo >&2 "Please define 'CONFIG_DEFAULT_DEVICE_TREE'"; \ | echo >&2 "or build with 'DEVICE_TREE=<device_tree>' argument"; \ | echo >&2; \ | /bin/false) | | Device Tree Source is not correctly specified. | Please define 'CONFIG_DEFAULT_DEVICE_TREE' | or build with 'DEVICE_TREE=<device_tree>' argument | | /home/raxesh/res/build-imx7ulpevk-test/workspace/sources/u-boot-fslc/dts/Makefile:28: recipe for target 'arch/arm/dts/imx7ulp-evk-mipi.dtb' failed | make[2]: *** [arch/arm/dts/imx7ulp-evk-mipi.dtb] Error 1 | /home/raxesh/res/build-imx7ulpevk-test/workspace/sources/u-boot-fslc/Makefile:1087: recipe for target 'dts/dt.dtb' failed | make[1]: *** [dts/dt.dtb] Error 2 | make[1]: Leaving directory '/home/raxesh/res/build-imx7ulpevk-test/tmp/work/imx7ulpevk-poky-linux-gnueabi/u-boot-fslc/v2020.01+git999-r0/u-boot-fslc-v2020.01+git999/mx7ulp_evk_config' | Makefile:167: recipe for target 'sub-make' failed | make: *** [sub-make] Error 2 | make: Leaving directory '/home/raxesh/res/build-imx7ulpevk-test/workspace/sources/u-boot-fslc' | ERROR: oe_runmake failed | WARNING: exit code 1 from a shell command. | WARNING: /home/raxesh/res/src/poky/bitbake/lib/bb/build.py:570: ResourceWarning: unclosed file <_io.TextIOWrapper name='/home/raxesh/res/build-imx7ulpevk-test/workspace/sources/u-boot-fslc/singletask.lock' mode='a+' encoding='UTF-8'> | exec_func(task, localdata) | | ERROR: Function failed: do_compile (log file is located at /home/raxesh/res/build-imx7ulpevk-test/tmp/work/imx7ulpevk-poky-linux-gnueabi/u-boot-fslc/v2020.01+git999-r0/temp/log.do_compile.3761) ERROR: Task (/home/raxesh/res/src/meta-res/recipes-bsp/u-boot/u-boot-fslc_2020.01.bb:do_compile) failed with exit code '1' NOTE: Tasks Summary: Attempted 647 tasks of which 639 didn't need to be rerun and 1 failed. Summary: 1 task failed: /home/raxesh/res/src/meta-res/recipes-bsp/u-boot/u-boot-fslc_2020.01.bb:do_compile Summary: There was 1 WARNING message shown. Summary: There were 2 ERROR messages shown, returning a non-zero exit code. ... ... ...

Re: issue: fdt_file gets changed after reboot

nxf63675 — Thu, 12 Aug 2021 03:35:05 GMT

Hi @Raxesh-Oriya,

Well, reviewing the log you share this is because the device tree is not correctly specified, take a look at the next post that could help you:

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/How-to-change-Linux-Kernel-configuration-file-in-Yocto-Project/tac-p/1112101

Regards,

Israel.