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March 18, 2026
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Unable to build flashlayout for eMMC for stm32mp25-disco target in Yocto

  • March 18, 2026
  • 1 reply
  • 159 views

I am running into issues building for the eMMC storage target for the `stm32mp25-disco` MACHINE type.

I thought that adding "emmc" to `BOOTDEVICE_LABELS` should be enough to trigger building emmc flashlayout files. Is that not the case? I haven't found clear documentation on the subject.

I tried making modifications to both `local.conf` and the machine conf directly. I was able to confirm the change takes affect with `bitbake -e`. Each time I build an image it only builds the flashlayout files for `sdcard`. What am I missing?

mkdir yocto
cd yocto
repo init -u https://github.com/STMicroelectronics/oe-manifest -b refs/tags/openstlinux-6.6-yocto-scarthgap-mpu-v25.08.27
repo sync

DISTRO=openstlinux-weston MACHINE=stm32mp25-disco source layers/meta-st/scripts/envsetup.sh
printf "%s\n" 'BOOTDEVICE_LABELS = "emmc"' >>conf/local.conf
bitbake core-image-minimal

ls -l tmp-glibc/deploy/images/stm32mp25-disco/flashlayout_core-image-minimal/optee/
FlashLayout_sdcard_stm32mp257f-dk-ca35tdcid-ostl-m33-examples-optee.tsv FlashLayout_sdcard_stm32mp257f-dk-ca35tdcid-ostl-optee.tsv FlashLayout_sdcard_stm32mp257f-dk-optee.tsv

bitbake -e core-image-minimal | grep "^BOOT"
BOOTDEVICE_LABELS="emmc sdcard"
BOOTSCHEME_LABELS="optee"
BOOTSCHEME_REPLACE="optee"
Best answer by Erwan SZYMANSKI

Hello @kcghost ,
Can you try with the stm32mp2.conf machine first ? 

The stm32mp25-disco.conf is given as example to help you creating your own machine, and does not bring all the features possible (such as eMMC storage). You can get inspired by the generic conf and adapt the machine directly (maybe modifying in local.conf cannot work in this context).

In summary, if you just want to make some quick tests on MP2-DK board, keep the generic stm32mp2 machine. If you want to fine tune a specific machine, I suggest you to create your own one.

Kind regards,
Erwan.

1 reply

Erwan SZYMANSKI
Erwan SZYMANSKIBest answer
Technical Moderator
March 18, 2026

Hello @kcghost ,
Can you try with the stm32mp2.conf machine first ? 

The stm32mp25-disco.conf is given as example to help you creating your own machine, and does not bring all the features possible (such as eMMC storage). You can get inspired by the generic conf and adapt the machine directly (maybe modifying in local.conf cannot work in this context).

In summary, if you just want to make some quick tests on MP2-DK board, keep the generic stm32mp2 machine. If you want to fine tune a specific machine, I suggest you to create your own one.

Kind regards,
Erwan.

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kcghostAuthor
Associate
March 19, 2026

Thanks! The generic `stm32mp2` machine generates all the expected flashlayout files. Since the machine conf is loaded after `local.conf` I did need to make a custom machine type to override some settings, but it appears to work now with the generic type as a base.