OpenEmbedded BSP layer for DH electronics STM32MP1 platforms

This layer provides BSP for DH electronics STM32MP1 platforms.

Dependencies

This layer depends on:

URI: git://git.yoctoproject.org/poky
- branch: dunfell
- layers: meta
URI: https://source.denx.de/denx/meta-mainline-common.git
- branch: dunfell-3.1

Building image

The OE build of this layer can be set up either manually or automatically using the KAS tool. Both options yield equal result. The manual option is more flexible, the kas option is easier for starters.

Building image (kas)

The KAS tool downloads select OE layers, emits matching bblayers.conf and local.conf, sets up required OE build variables and even executes the build. The tool also provides menu-based build configuration.

A good starting point for setting up the build using KAS is the KAS documentation, namely Introduction, User Guide, Command line usage and Environment variables.

First, install KAS to current user local bin directory:

$ pip3 install kas

Second, clone this metalayer git repository into a location accessible to the build system:

git clone https://github.com/dh-electronics/meta-dhsom-stm32-bsp.git -b dunfell-3.1

Third, configure the build parameters, especially the work directory where the build stores all the data. This directory must have sufficient amount of space, around 25 GiB for basic build and 100 GiB for build with all examples.

The kas menu command displays an ncurses-based menu, which offers selection of one of MACHINEs supported by this metalayer and the option to perform full build including meta-dhsom-extras example and demonstration layer. Select suitable MACHINE (use SPACEBAR to change the selection), optionally enable full build (takes longer and requires extra disk space), and use either Save & Build or Save & Exit button to save changes and exit the menu (use TAB key to navigate the buttons).

$ export KAS_WORK_DIR=/path/to/work/directory/
$ cd meta-dhsom-stm32-bsp/kas
$ PATH=${PATH}:~/.local/bin kas menu

The *** Inferred and expert settings *** section does not need to be changed.

The Save & Build button stores the build configuration in ${KAS_WORK_DIR}/.config.yaml and immediately triggers default build target for the selected configuration. The Save & Exit button stores the build configuration and exits, the KAS build can then be resumed using KAS build command, kas build.

Building image (manual)

A good starting point for setting up the build environment is is the official Yocto Project wiki.

https://www.yoctoproject.org/docs/3.1/brief-yoctoprojectqs/brief-yoctoprojectqs.html

Before attempting the build, the following metalayer git repositories shall be cloned into a location accessible to the build system and a branch listed below shall be checked out. The examples below will use /path/to/OE/ as a location of the metalayers.

https://source.denx.de/denx/meta-mainline-common.git (branch: dunfell-3.1)
https://github.com/dh-electronics/meta-dhsom-stm32-bsp.git (branch: dunfell-3.1)
git://git.yoctoproject.org/poky (branch: dunfell)

With all the source artifacts in place, proceed with setting up the build using oe-init-build-env as specified in the Yocto Project wiki.

In addition to the content in the wiki, the aforementioned metalayers shall be referenced in bblayers.conf in this order:

BBLAYERS ?= " \
  /path/to/OE/poky/meta \
  /path/to/OE/meta-mainline-common \
  /path/to/OE/meta-dhsom-stm32-bsp \
  "

The following specifics should be placed into local.conf:

MACHINE = "dh-stm32mp1-dhcom-pdk2"
DISTRO = "nodistro"

Note that MACHINE must be either of:

dh-stm32mp1-dhcom-drc02
dh-stm32mp1-dhcom-pdk2
dh-stm32mp1-dhcom-picoitx
dh-stm32mp1-dhcor-avenger96

Adapt the suffixes of all the files and names of directories further in this documentation according to MACHINE.

Both local.conf and bblayers.conf are included verbatim in full at the end of this readme.

Once the configuration is complete, a basic demo system image suitable for evaluation can be built using:

$ bitbake core-image-minimal

Once the build completes, the images are available in:

tmp-glibc/deploy/images/dh-stm32mp1-dhcom-pdk2/

The SD card image is specifically in:

core-image-minimal-dh-stm32mp1-dhcom-pdk2.wic

And shall be written to the SD card using dd:

$ dd if=core-image-minimal-dh-stm32mp1-dhcom-pdk2.wic of=/dev/sdX bs=8M

Example local.conf

MACHINE = "dh-stm32mp1-dhcom-pdk2"
DL_DIR = "/path/to/OE/downloads"
DISTRO ?= "nodistro"
PACKAGE_CLASSES ?= "package_rpm"
EXTRA_IMAGE_FEATURES = "debug-tweaks"
USER_CLASSES ?= "buildstats"
PATCHRESOLVE = "noop"
BB_DISKMON_DIRS = "\
    STOPTASKS,${TMPDIR},1G,100K \
    STOPTASKS,${DL_DIR},1G,100K \
    STOPTASKS,${SSTATE_DIR},1G,100K \
    STOPTASKS,/tmp,100M,100K \
    ABORT,${TMPDIR},100M,1K \
    ABORT,${DL_DIR},100M,1K \
    ABORT,${SSTATE_DIR},100M,1K \
    ABORT,/tmp,10M,1K"
PACKAGECONFIG:append:pn-qemu-native = " sdl"
PACKAGECONFIG:append:pn-nativesdk-qemu = " sdl"
CONF_VERSION = "1"

Example bblayers.conf

# LAYER_CONF_VERSION is increased each time build/conf/bblayers.conf
# changes incompatibly
POKY_BBLAYERS_CONF_VERSION = "2"

BBPATH = "${TOPDIR}"
BBFILES ?= ""

BBLAYERS ?= " \
	/path/to/OE/poky/meta \
	/path/to/OE/meta-mainline-common \
	/path/to/OE/meta-dhsom-stm32-bsp \
	"