How to generate default u-Boot environment variables ?

khang_letruong — Sun, 25 Jun 2023 07:37:47 GMT

Dear Community,

From the tutorial in attachment, it is said :

I would like to know if there's any way to have default u-Boot's environment variables in the storage without using the saveenv command once as we plan to remove the serial debug interface and serial download interface (i.e. without u-Boot access) from an iMX8M Plus based system with SD card as only storage, please ?

Thanks and best regards,

Khang

Re: How to generate default u-Boot environment variables ?

BiyongSUN — Sun, 25 Jun 2023 09:01:05 GMT

It is no difference between under arm linux with real device sdcard/emmc and x86/x64 linux with sdcard mirror(or real sdcard).

The document is just under arm linux with real device sdcard/emmc.

Now You just need to compile a x86/64 fw_setenv/fw_printenv.

Others are the exactly the same.

you can use "make u-boot-initial-env" to get the default uboot env. (So far, the yocto use the same way output the env in its deploy)

Here is one example, yocto deploy. u-boot-imx-initial-env-imx8mmevk-sd-2020.04-r0 is the default env.

mx8mm-evk-qca-wifi--5.4-r0-imx8mmevk-20210709103222.dtb tee.mx8mmevk.bin
imx8mm-evk-qca-wifi.dtb u-boot.bin
imx8mm-evk-qca-wifi-imx8mmevk.dtb u-boot.bin-sd
imx8mm-evk-revb-qca-wifi--5.4-r0-imx8mmevk-20210709103222.dtb u-boot-imx8mmevk.bin
imx8mm-evk-revb-qca-wifi.dtb u-boot-imx8mmevk.bin-sd
imx8mm-evk-revb-qca-wifi-imx8mmevk.dtb u-boot-imx-initial-env-imx8mmevk-sd
imx8mm-evk-rm67191--5.4-r0-imx8mmevk-20210709103222.dtb u-boot-imx-initial-env-imx8mmevk-sd-2020.04-r0
imx8mm-evk-rm67191.dtb u-boot-imx-initial-env-sd
imx8mm-evk-rm67191-imx8mmevk.dtb u-boot-sd-2020.04-r0.bin
imx8mm-evk-root--5.4-r0-imx8mmevk-20210709103222.dtb u-boot-spl.bin

If you need a binary env, you can use mkenvimage to convert it.

In the following document, you can see the fw_setenv apply uboot environment into a sdcard mrrior.

create sdcard mirror under windows
https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/create-sdcard-mirror-under-windows/ta-p/1472741

You can see a.sdcard is a mirror not a real device.

fw_env.config

#a.sdcard 0x400000 0x4000 #8MQ,8MM, 8MN, 8MP since lf-5.10.52-2.1.0
#a.sdcard 0x400000 0x2000 #8, 8X,8ULP
a.sdcard 0x400000 0x1000 #8MQ,8MM, 8MN, 8MP

and

fw_setenv has "-f" for the first time, the device has no env yet. The env file is the previous command "make u-boot-initial-env", you got.

You can use the -f or you can prepare a scard/emmc mirror has env inside(use x86/x64 fw_setenv set it or use mkenvimage get binary env to integrate it).

fw_setenv (compiled Dec 27 2021)
Usage fw_setenv [OPTION]
-h, : print this help
-c, --config <filename> : configuration file (old fw_env.config)
-f, --defenv <filename> : default environment if no one found
-V, : print version and exit
-s, --script <filename> : read variables to be set from a script

In the document, the swupdate uses the same way for the first time when device has no env.

SWUpdate OTA i.MX8MM EVK / i.MX8QXP MEK

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/SWUpdate-OTA-i-MX8MM-EVK-i-MX8QXP-MEK/ta-p/1307416

Lots of ways to achieve your goal.

You also can consider the "uENV.txt" way.

topic How to generate default u-Boot environment variables ? in i.MX Processors

How to generate default u-Boot environment variables ?

Re: How to generate default u-Boot environment variables ?