How to create a custom uboot build in Yocto mickledore (UBOOT_CONFIG ?)

[jamescc]

Is there any documentation or guidance on how to configure Yocto to deploy a custom u-boot image? 

I've been following https://wiki.st.com/stm32mpu/wiki/How_to_configure_U-Boot_for_your_board and https://wiki.stmicroelectronics.cn/stm32mpu/wiki/STM32MP15_U-Boot with some success, however these stop short of Yocto.

I am able to build our custom build (defconfig, device-tree, with custom source adjustments) but I'm struggling to integrate into Yocto, to complete the flow to a final SD Card image.

When I add my variant to `UBOOT_CONFIG` it builds it, but `trusted_stm32mp15` is appended and seems to be the one in the deploy folder: tmp-glibc/deploy/images/<IMAGE_NAME>/u-boot/ and tmp-glibc/deploy/images/<IMAGE_NAME>/fip

My machine.conf file has:

UBOOT_CONFIG = "viper_butcombe_beta"

UBOOT_CONFIG[viper_butcombe_beta] = "viper-innovations_butcombe-beta_defconfig,,u-boot.dtb"

and I see layers/meta-st/meta-st-stm32mp/conf/machine/include/st-machine-common-stm32mp.inc has the lines:

# STM32mp15
UBOOT_CONFIG:append:stm32mp15common = " ${@bb.utils.contains_any('BOOTSCHEME_LABELS', 'optee', 'trusted_stm32mp15', '', d)} "

UBOOT_CONFIG[trusted_stm32mp15] = "stm32mp15_defconfig,,u-boot.dtb"

`stm32mp15common` is in our MACHINEOVERRIDES  (should it be?) and `optee` is in our BOOTSCHEME_LABELS.  It seems I need to be doing something with these.  As we want to keep to ST's advised way of booting, presumably BOOTSCHEME_LABELS should remain unchanged.

Are there any example recipes where people have added a custom u-boot image?

[Erwan SZYMANSKI]

Hello @jamescc,
Regarding your summary, I think you made the major part of the work now !
Can you share me your machine.conf file ? Did you well checked that your UBOOT_CONFIG variable is made after the include conf/machine/include/st-machine-common-stm32mp.inc line ? Otherwise it will be overwritten by UBOOT_CONFIG = " ".

Kind regards,
Erwan

[jamescc]

Thanks for your response.  Yes it felt like this should have been the less complex part.

Here is our `machine.conf` file.  It is nothing too elaborate at this stage.  The setting of UBOOT_CONFIG is done at the end, long after include conf/machine/include/st-machine-common-stm32mp.inc

As we are about to start the bring-up of this board, we've gone down the route of patching the existing ST uboot DK2 and EVAL board implementation for now, but ideally, I'd like to create a new u-boot board.

Thanks JamesCC

#@TYPE: Machine Butcombe development from the Alpha boards to the DK2 development
#@NAME: butcombe-dk2-alpha
#@DESCRIPTION: Configuration for STM32CubeMX generated project
#@NEEDED_BSPLAYERS: layers/meta-openembedded/meta-oe layers/meta-openembedded/meta-python layers/meta-butcombe

# Define specific common machine name
MACHINEOVERRIDES .= ":stm32mp1common:stm32mp15common"

include conf/machine/include/st-machine-common-stm32mp.inc
include conf/machine/include/st-machine-providers-stm32mp.inc

# =========================================================================
# Chip architecture
# =========================================================================
DEFAULTTUNE = "cortexa7thf-neon-vfpv4"
include conf/machine/include/arm/armv7a/tune-cortexa7.inc

# =========================================================================
# boot scheme
# =========================================================================
BOOTSCHEME_LABELS += "optee"

# =========================================================================
# boot device
# =========================================================================
# Define the boot device supported
#BOOTDEVICE_LABELS += "emmc"
#BOOTDEVICE_LABELS += "nand-4-256"
#BOOTDEVICE_LABELS += "nor-sdcard"
BOOTDEVICE_LABELS += "sdcard"

# =========================================================================
# boot device
# =========================================================================
BOOTDEVICE_LABELS ?= "SDcard"

# =========================================================================
# Machine settings
# =========================================================================
STM32MP_DEVICETREE = "${CUBEMX_DTB}"

# =========================================================================
# Machine features (default for stm32mp1 like)
# =========================================================================
MACHINE_FEATURES += "splashscreen"
MACHINE_FEATURES += "watchdog"
MACHINE_FEATURES += "${@'gpu' if d.getVar('ACCEPT_EULA_'+d.getVar('MACHINE')) == '1' else ''}"
MACHINE_FEATURES += "m4copro"

# =========================================================================
# Device Storage
# =========================================================================
# Enable the board device storage support with CUBEMX_DTB according to BOOTDEVICE_LABELS
DEVICE_BOARD_ENABLE:NAND    += "${@bb.utils.contains('BOOTDEVICE_LABELS', 'nand-4-256', '${CUBEMX_DTB}', '', d)}"
DEVICE_BOARD_ENABLE:NOR     += "${@bb.utils.contains('BOOTDEVICE_LABELS', 'nor-sdcard' , '${CUBEMX_DTB}', '', d)}"
DEVICE_BOARD_ENABLE:EMMC    += "${@bb.utils.contains('BOOTDEVICE_LABELS', 'emmc', '${CUBEMX_DTB}', '', d)}"
DEVICE_BOARD_ENABLE:SDCARD  += "${@bb.utils.contains('BOOTDEVICE_LABELS', 'sdcard', '${CUBEMX_DTB}', '', d)}"

# =========================================================================
# Flashlayout
# =========================================================================
# Set the FLASHLAYOUT_TYPE_LABELS to CUBEMX_DTB according to BOOTDEVICE_LABELS
FLASHLAYOUT_TYPE_LABELS:emmc        = "${@bb.utils.contains('BOOTDEVICE_LABELS', 'emmc', '${CUBEMX_DTB}', '', d)}"
FLASHLAYOUT_TYPE_LABELS:nand-4-256  = "${@bb.utils.contains('BOOTDEVICE_LABELS', 'nand-4-256', '${CUBEMX_DTB}', '', d)}"
FLASHLAYOUT_TYPE_LABELS:nor-sdcard  = "${@bb.utils.contains('BOOTDEVICE_LABELS', 'nor-sdcard' , '${CUBEMX_DTB}', '', d)}"
FLASHLAYOUT_TYPE_LABELS:sdcard      = "${@bb.utils.contains('BOOTDEVICE_LABELS', 'sdcard', '${CUBEMX_DTB}', '', d)}"

# Specific settings for 'extensible' and 'deleteall' configurations
FLASHLAYOUT_CONFIG_LABELS:deleteall = "cubemx"
FLASHLAYOUT_TYPE_LABELS:deleteall:cubemx = "${CUBEMX_DTB}"
FLASHLAYOUT_TYPE_LABELS:extensible = "${CUBEMX_DTB}"

# =========================================================================
# CubeMX extra config
# =========================================================================
ENABLE_CUBEMX_DTB ?= "1"

###########################################################################
#
# User machine customization sections
#
###########################################################################

# Boot Scheme
# =========================================================================
#BOOTSCHEME_LABELS += "optee"
# (set above)

# Support Feature Choice
# =========================================================================
# Define the features to enable on board

# Specific firmwares and kernel modules configuration
# =========================================================================
# Set the list of kernel module to be auto-loaded during boot
KERNEL_MODULE_AUTOLOAD += ""

# CubeMX Project Config
# =========================================================================
# Assign CubeMX Board devicetree and project path name
CUBEMX_DTB = "stm32mp157d-butcombe-beta-mx"
CUBEMX_PROJECT ?= "${TOPDIR}/../layers/meta-butcombe/device-tree/butcombe-beta"

#Indicate which STM32MP package are used: 'A', 'C', 'D' or 'F'  A:No Crypt C:Crypt D:no Crypt, Performance, F:Crypt, Performance
CUBEMX_SOC_PACKAGE = 'D'

# Indicate the size of DDR available on BOARD: 512 or 1024 (size in MB unit)
CUBEMX_BOARD_DDR_SIZE = "512"

# Indicate if you like to disable the DVFS which are activated by default
#CUBEMX_SOC_DVFS_OFF = "0"

# U-Boot config
UBOOT_CONFIG = "viper_butcombe_beta"
UBOOT_CONFIG[viper_butcombe_beta] = "viper-innovations_butcombe-beta_defconfig,,u-boot.dtb"

[Erwan SZYMANSKI]

Hi @jamescc ,
Sorry for the delay, I was some days off.

Regarding recipes process, I ask myself if the root cause is not the MACHINEOVERRIDES statement. Because I think that whatever you do with the UBOOT_CONFIG after, it will still take the first config appended that is trusted_stm32mp15 (but this is a pure theory by reading the recipe).

Is it possible for you to make a test without this overriding statement ?

Kind regards,
Erwan.

[jamescc]

Thanks for your response; we will return to this after our board bring-up (which has taken our attention right now).