STMicroelectronics feed for OpenWRT

This repository is an OpenWRT feed dedicated to supporting the STMicroelectronics STM32MP1 platforms.

Supported devices

STM32MP157F-DK2: minimal support for the STM32MP157F-DK2
STM32MP135F-DK: minimal support for the STM32MP135F-DK
STM32MP157F-DK2-DEMO: based on the STM32MP157F-DK2 device including additional packages like a web interface to configure the device.
STM32MP135F-DK-DEMO: based on the STM32MP135F-DK device including additional packages like a web interface to configure the device.

Supported features	STM32MP157F-DK2	STM32MP135F-DK
Sysupgrade	yes	yes
Ethernet	yes	yes
Watchdog	yes	yes
RTC	yes	yes
RNG (Optee)	yes	yes
LED	yes	yes
Button	no	yes (USER2)
Wifi	yes	yes
USB Type-A	yes	yes

BSP

This feed is based on the STPM32MP1 BSP v5.0.

Components	Version
TF-A	v2.8-stm32mp-r1
U-Boot	v2022.10-stm32mp-r1
OPTEE	3.19.0-stm32mp-r1
Linux	OpenWRT kernel + v6.1-stm32mp-r1

For the kernel, the patches from the v6.1-stm32mp branch until the tag v6.1-stm32mp-r1 were added.
They are available in target/linux/stm32/patches-6.1/.

Getting started

Pre-requisites

In order to use OpenWRT, you need to have a Linux or Unix like distribution installed on your workstation. And you need to install a set of packages as described in the OpenWRT Build system setup.

Getting the code

The feed is designed to work with the master branch of OpenWRT (last tested commit is 904aa43865).

$ git clone -b master https://git.openwrt.org/openwrt/openwrt.git
$ cd openwrt
$ git checkout 904aa43865

Next step is to add the STMicroelectronics feed in the feeds.conf.default file.

$ cat feeds.conf.default
src-git st https://github.com/bootlin/openwrt-feed-st.git
src-git packages https://git.openwrt.org/feed/packages.git
src-git luci https://git.openwrt.org/project/luci.git
src-git routing https://git.openwrt.org/feed/routing.git
src-git telephony https://git.openwrt.org/feed/telephony.git
#src-git video https://github.com/openwrt/video.git
#src-git targets https://github.com/openwrt/targets.git
#src-git oldpackages http://git.openwrt.org/packages.git
#src-link custom /usr/src/openwrt/custom-feed

Then fetch the code of all feeds

$ ./scripts/feeds update -a

Install the feeds

Install stm32 target

$ ./scripts/feeds install stm32

Install all other packages

$ ./scripts/feeds install -a -f

(Some overriding warnings can occur, if you used -f please ignore them).

Install ptgen patch

We need to apply a patch on the host tool firmware-utils to be able to build bootable images.

$ mkdir tools/firmware-utils/patches/
$ cp feeds/st/patches/0001-ptgen-fix-limitation-for-active-partition-in-GPT.patch \
     tools/firmware-utils/patches/

Configure and build

Run make menuconfig

$ make menuconfig

Then select STMicroelectronics STM32 for the Target System, STM32MP1 boards for the Subtarget, and select the Target Profile corresponding to your hardware (for example STMicroelectronics STM32MP135F-DK).

Then to start the build.

$ make -j$(nproc)

Flashing and booting the system

All images generated for the subtarget stm32mp1 are stored in bin/targets/stm32/stm32mp1/. The images to flash on the SDCard are openwrt-stm32-stm32mp1-stm32mpXXXXX-ext4-factory.img.gz.

$ gzip -d -c bin/targets/stm32/stm32mp1/openwrt-stm32-stm32mp1-stm32mp135f-dk-ext4-factory.img.gz | dd of=/dev/sdX

(Note: this assumes your SD card appears as /dev/sdX on your system.)

Then:

Insert the microSD card
- STM32MP157: connector CN15
- STM32MP135: connector CN3
Plug a micro-USB cable and run your serial communication program on /dev/ttyACM0.
- STM32MP157: connector CN11
- STM32MP135: connector CN10
Configure the SW1 switch to boot on SD card
- STM32MP157: BOOT0 and BOOT2 to ON
- STM32MP135: BOOT0 to ON, BOOT1 to OFF, BOOT2 to ON
Plug a USB-C cable to power-up the board
- STM32MP157: connector CN6
- STM32MP135: connector CN12
The system will start, with the console on UART. The default user is root with no password. The login is automatic.

BusyBox v1.36.1 (2024-02-14 15:44:53 UTC) built-in shell (ash)

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 OpenWrt SNAPSHOT, r24943+13-3a073a0212
 -----------------------------------------------------
=== WARNING! =====================================
There is no root password defined on this device!
Use the "passwd" command to set up a new password
in order to prevent unauthorized SSH logins.
--------------------------------------------------
root@OpenWrt:/#

Additional informations

This chapter contains some informations which are specific to the stm32 target. For the generic informations, please refer to the Official OpenWRT documentation.

Ethernet

The configuration of Ethernet interfaces is the default OpenWRT configuration:

STM32MP157F-DK2: lan interface
STM32MP135F-DK: lan interface (ETH1) and wan interface (ETH2)

The lan interface is configured with a static ip address 192.168.1.1 and a dhcp server is running.
The wan interface is in dhcp mode.
By default the management protocols are only accessible from the lan interface.

System upgrade

For a system upgrade, an upgrade image shall be used (image labelled ...-sysupgrade.img.gz).

The demo and non-demo profiles are compatible, it means you can update a STM32MP135F-DK profile with a STM32MP135F-DK-DEMO image (vice versa) for example.

By default, the sysupgrade mechanism updates the partitions one by one. If the partition table is different (for example the rootfs partition is 10MiB bigger), the full image is written.

The U-Boot environment variables are always preserved during an upgrade.
To erase the environment variables, flash the factory image on the SDCard or use the env erase command from U-Boot.

Useful link: Upgrading OpenWrt firmware using LuCI and CLI

Button

The kernel module gpio-button-hotplug is used to support buttons.
The STM32MP135F-DK has one supported button: USR2 (key BTN_1).

To easily test the button:

mkdir -p /etc/hotplug.d/button

cat << "EOF" > /etc/hotplug.d/button/buttons
logger "the button was ${BUTTON} and the action was ${ACTION}"
EOF

root@OpenWrt:/# logread -f
Fri Mar 15 14:28:09 2024 user.notice root: the button was BTN_1 and the action was pressed
Fri Mar 15 14:28:09 2024 user.notice root: the button was BTN_1 and the action was released

Useful link: Attach functions to a push button

LED

One LED is defined and labelled blue:heartbeat (LD8 for STM32MP157F-DK2 and LD3 for STM32MP135F-DK). By default it is configured to use the heartbeat trigger.

Useful link: LED Configuration

USB

Only mass storage are supported on the USB Type-A by default.

srdgame / openwrt-feed-st