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G
GLaure
Explorer
May 9, 2023
Solved

U-BOOT environment variables not stored in u-boot-env partition

  • May 9, 2023
  • 1 reply
  • 4314 views

Hi,

​

I am confused how to correctly set u-boot environment variables in a system based on OpenST Linux 4.1 and follows DK2 settings.

​

The partition layout looks like this:

#Opt	 Id	 	Name	 Type	 IP	 Offset	 Binary
-	 0x01	fsbl1-boot	Binary	 none	0x0	 arm-trusted-firmware/tf-a-stm32mp157f-nexio-usb.stm32
-	 0x03	fip-boot	Binary	 none	0x0	 fip/fip-stm32mp157f-nexio-trusted.bin
P	 0x04	fsbl1	 Binary	 mmc0	0x00004400	arm-trusted-firmware/tf-a-stm32mp157f-nexio-sdcard.stm32
P	 0x05	fsbl2	 Binary	 mmc0	0x00044400	arm-trusted-firmware/tf-a-stm32mp157f-nexio-sdcard.stm32
P	 0x06	metadata1	Binary	 mmc0	0x00084400	arm-trusted-firmware/metadata.bin
P	 0x07	metadata2	Binary	 mmc0	0x000C4400	arm-trusted-firmware/metadata.bin
P	 0x08	fip-a	 FIP	 mmc0	0x00104400	fip/fip-stm32mp157f-nexio-trusted.bin
PED	 0x09	fip-b	 FIP	 mmc0	0x00504400	none
PED	 0x0A	u-boot-env	Binary	 mmc0	0x00904400	none
P	 0x10	bootfs	 System	 mmc0	0x00984400	st-image-bootfs-openstlinux-weston-stm32mp1-nexio.ext4
P	 0x11	vendorfs FileSystem	 mmc0	0x04984400	st-image-vendorfs-openstlinux-weston-stm32mp1-nexio.ext4
P	 0x12	rootfs	 FileSystem	 mmc0	0x05984400	st-image-core-openstlinux-weston-stm32mp1-nexio.ext4
P	 0x13	rootfs	 FileSystem	 mmc0	0x45984400	st-image-core-openstlinux-weston-stm32mp1-nexio.ext4
E	 0x14	writeable	FileSystem	 mmc0	0x85984400	none	# 256kB persistent memory 
E	 0x15	dummy	 FileSystem	 mmc0	0x859C4400	none	# unused

​My idea is to use u-boot boot.scr.cmd to be able to switch between the two root filesystems.

fw_env.config looks like this:

# Block device example
/dev/disk/by-partlabel/u-boot-env		0x3bc00		0x2000
/dev/disk/by-partlabel/u-boot-env		0x3bc00		0x2000

I got the start offset by looking into u-boot-env by using hexdump.

After boot I am able to use fw_printenv and fw_setenv and I see the changes made to u-boot-env.

​But I have a number of issues with this approach:

  1. boot.scr.img is not always executed. It seems only to get executed at the first boot.
  2. u-boot prompt: env set var 123; env save; does not seem to save the variable to the u-boot-env partition. In fact after using hexdump I found out the value is stored to the fip-b partition. Why doesnt it use u-boot-dev?
  3. Using fw_setenv does change the value in u-boot-dev, but on the u-boot prompt I see the previous value. The one from the fip-b partition.

How can I configure the system so that u-boot and the rootfs use the same device for storing the FW environment variables?

Thank you 1000 times!

bye Gunther

    This topic has been closed for replies.
    Best answer by GLaure

    I believe I found the culprit;

    Somehow our u-boot device tree set:

    u-boot,mmc-env-partition = "fip";

    I am changing it to:

    u-boot,mmc-env-partition = "u-boot-env";

    and expecting consistent behavior.

    Bye Gunther

    1 reply

    G
    GLaureAuthorAnswer
    Explorer
    May 9, 2023

    I believe I found the culprit;

    Somehow our u-boot device tree set:

    u-boot,mmc-env-partition = "fip";

    I am changing it to:

    u-boot,mmc-env-partition = "u-boot-env";

    and expecting consistent behavior.

    Bye Gunther

    P
    PatrickD
    ST Employee
    June 19, 2023

    Hi,

    I confirm, that is a modification in U-Boot device tree on ST boards for OpenSTLinux migration V3.X => V4.X to respect the new flashlayout = https://wiki.st.com/stm32mpu/wiki/STM32CubeProgrammer_flashlayout#SD_card

    A new partition is created for save the U-Boot environment, it is no more saved at the end of the FIP partition.

    If you can adopt the new SD-Card partitioning (the new tsv files) you must update this part in your U-Boot device tree:
    https://wiki.st.com/stm32mpu/wiki/U-Boot_overview#U-Boot_environment_variables

    sorry if it was clear enough.

    Patrick

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