ODYSSEY STM32MP157C ARM Trusted Firmware support?

Has ATF been ported to the Seed SoM and the ODYSSEY? I imagine it would require adding the device tree at the very least

Stm32mp157c is ATF supported, default support, Seeed does not need to do anything.

That makes sense- however neither building the ATF or using the OpenSTLinux ATF image seems to work. I load it using STM32CubeProgrammer and then it stops responding. Flashing it to the eMMC boot partition manually shows that when it boots it has an ATF panic. In contrast I can load U-Boot SPL then load U-Boot’s SPL again. I’m not sure if this is due to my board setup, so it would be good to know if this has been tested or there’s an official image I can try.

One thing I noticed is that in the ATF tree the PMIC and eMMC are on the wrong buses for the SoM. Even correcting that didn’t help. Could it be failing to bring up the RAM somehow?

Alright, so 8 hours later I have a few answers:

  1. Mainline ATF runs with device tree modifications to use sdmmc2 for eMMC and find the PMIC on the I2C bus 2. Note that this doesn’t fix up the PMIC device tree to use the right values for the LDOs.
diff --git a/fdts/stm32mp157-pinctrl.dtsi b/fdts/stm32mp157-pinctrl.dtsi
index 7fd902bd2..0d6096121 100644
--- a/fdts/stm32mp157-pinctrl.dtsi
+++ b/fdts/stm32mp157-pinctrl.dtsi
@@ -239,6 +239,16 @@
+                        i2c2_pins_a: i2c2-0 {
+                                pins {
+                                        pinmux = <STM32_PINMUX('H', 4, AF4)>, /* I2C2_SCL */
+                                                 <STM32_PINMUX('H', 5, AF4)>; /* I2C2_SDA */
+                                        bias-disable;
+                                        drive-open-drain;
+                                        slew-rate = <0>;
+                                };
+                        };
                        sdmmc2_b4_pins_a: sdmmc2-b4-0 {
                                pins1 {
                                        pinmux = <STM32_PINMUX('B', 14, AF9)>, /* SDMMC2_D0 */
diff --git a/fdts/stm32mp157a-dk1.dts b/fdts/stm32mp157a-dk1.dts
index 4ea83f7cd..78681b0ba 100644
--- a/fdts/stm32mp157a-dk1.dts
+++ b/fdts/stm32mp157a-dk1.dts
@@ -29,9 +29,9 @@
-&i2c4 {
+&i2c2 {
        pinctrl-names = "default";
-       pinctrl-0 = <&i2c4_pins_a>;
+       pinctrl-0 = <&i2c2_pins_a>;
        i2c-scl-rising-time-ns = <185>;
        i2c-scl-falling-time-ns = <20>;
        status = "okay";
@@ -162,9 +162,9 @@
        status = "okay";
-&sdmmc1 {
+&sdmmc2 {
        pinctrl-names = "default";
-       pinctrl-0 = <&sdmmc1_b4_pins_a>;
+       pinctrl-0 = <&sdmmc2_b4_pins_a>;
        bus-width = <4>;
diff --git a/fdts/stm32mp157c.dtsi b/fdts/stm32mp157c.dtsi
index 91b20fa4a..cafdd6bf7 100644
--- a/fdts/stm32mp157c.dtsi
+++ b/fdts/stm32mp157c.dtsi
@@ -312,6 +312,20 @@
                        status = "disabled";
+                i2c2: i2c@40013000 {
+                        compatible = "st,stm32f7-i2c";
+                        reg = <0x40013000 0x400>;
+                        interrupt-names = "event", "error";
+                        interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>,
+                                     <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
+                        clocks = <&rcc I2C2_K>;
+                        resets = <&rcc I2C2_R>;
+                        #address-cells = <1>;
+                        #size-cells = <0>;
+                        status = "disabled";
+                };
                i2c4: i2c@5c002000 {
                        compatible = "st,stm32f7-i2c";
                        reg = <0x5c002000 0x400>;
  1. Commit 7c864b896791947bd299bb0625c0386afe827ef0 in ST’s tree is broken on the Seeed SoM, but the mainline version f564d439a957b96de24cc3c2e2bb5f2e8a052384 works? I had to replace them to get ATF to not immediately panic.
  2. Commit 606053d9b9e9080fb5269b1d05e8dd4390883a93 in ST’s tree is also broken, making the I2C2 bus which the PMIC is on unusable and causing a panic. This commit isn’t mainlined so I don’t know what’s going on here.

Edit: 2 is wrong. I was testing it wrong- the PMIC setting itself to secure will always break things for some reason. I’ll need to test more device tree stuff.

Edit 2: I’m not sure what to make of the PMIC security stuff. It works mainline but not out of tree.

I was directed to this: https://wiki.st.com/stm32mpu/wiki/PMIC_hardware_components

Apparently only I2C4 and I2C6 are supported for secure operation and as such aren’t supported by ST for this.

Yeah after about a week of trying to get this working, I’m giving up. ATF doesn’t work on this board.

Okay past me, cool it a little. ATF does work given some device tree tweaks, but for some reason it doesn’t boot Seeed’s Linux. I spent a week trying to get mainline working with Ethernet but in the end the problem was that ST’s ‘st,eth_clk_sel’ is ‘st,eth-clk-sel’ in mainline. I was pretty sure ATF was mucking something up.

Okay for anyone else that’s going down this road, I’ve put up the code I’ve used to get it working:

ATF: https://git.lumina-sensum.com/LuminaSensum/arm-trusted-firmware/commits/WIP_v2.3-LS
Barebox: https://git.lumina-sensum.com/LuminaSensum/barebox/commits/WIP_next-LS
Linux: https://git.lumina-sensum.com/LuminaSensum/linux/commits/WIP_v5.8-LS

Thank you very much. Is it available on GitHub? Your private Git account is required and may not be accessible to regular users.

Oops, yeah it looks like it’s inaccessible. I’ll upload it to GitHub tomorrow or sooner. :slight_smile:

Ok, thank you again.

No problem. It’s a WIP, I’m not sure how well power management is in ATF. I had to backport some ST stuff to get shutdown working, but I’m not sure about suspend yet.

ATF: https://github.com/Jookia/arm-trusted-firmware/commits/WIP_v2.3-LS
Linux: https://github.com/Jookia/linux/commits/WIP_v5.8-LS

The commit to fix Ethernet (https://github.com/Jookia/linux/commit/6f589b1dfa37cb449584b5e827ac3117369a4446) should work in U-Boot/Barebox too.

Hello 166291,
I was struggling with the ATF long into the night when I stumbled upon this post. I had made the same changes as you but on the ST ATF repo and got the following.

NOTICE:  Model: STMicroelectronics STM32MP157C-DK2 Discovery Board
INFO:    Reset reason (0x15):
INFO:      Power-on Reset (rst_por)
INFO:    Using USB
INFO:      Instance 2
INFO:    Boot used partition fsbl1
NOTICE:  BL2: v2.0-r2.0(debug):v2.0-stm32mp-r2-dirty
INFO:    BL2: Doing platform setup
INFO:    PMIC version = 0x20
PANIC at PC : 0x2ffe6d03

Exception mode=0x00000016 at: 0x2ffda000

I figued I would give your repo a run and see if that works, but I end up with this

NOTICE:  Model: STMicroelectronics STM32MP157C-DK2 Discovery Board
INFO:    Reset reason (0x15):
INFO:      Power-on Reset (rst_por)
ERROR:   Boot interface not found
PANIC at PC : 0x2ffd91e1

I feel lost. Any ideas what I could be missing?

I am building with gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf and the string
make -C ${<your ATF repo cleaned with said branch checked out>} CROSS_COMPILE=${<as above>} PLAT=stm32mp1 LOG_LEVEL=40 DTB_FILE_NAME=stm32mp157c-dk2.dtb ARM_ARCH_MAJOR=7 ARCH=aarch32 AARCH32_SP=sp_min STM32MP_USB_PROGRAMMER=1 STM32MP_EMMC=1 STM32MP_SDMMC=1 all

I load the code with STM32CubeProgrammer/bin/STM32_Programmer_CLI -c port=usb1 -w flash.tsv


#Opt Id Name Type IP Offset Binary
- 0x01 fsbl1-boot Binary none 0x0 tf-a-stm32mp157c-dk2.stm32
- 0x03 ssbl-boot Binary none 0x0 u-boot.stm32

Last. Great thanks for the info in your post!

Best Regards

Yeah those are the the errors I’d get with STM’s repo. They have a bunch of code that would enable security features that reply on the STMPIC1 being on a different i2c bus adn seems to fail if that’s not the case. That’s why I gave up and just backported some stuff to get normal ATF working.

Any idea why I am getting

running the ATF from your repo?

Best regards

Are you on commit 75090fd1ae6723b0b2c10b5973108cfcd260bc54 ? You’re using dk2 as the device tree but I’ve only edited dk1 maybe that’s the issue?


Thanks again your replay.

The dk2 DTS just ‘#include “stm32mp157a-dk1.dts”’ and changes the model name so I consider them the same in terms of the ATF. And yes, I use commit 75090fd.

I recall seeing something like this a long time before. Could be something silly as the tsv file missing something.

The ST ATF has a case for USB

#ifdef STM32MP_USB
        INFO("Using USB\n");

Where as the other ATF does not. It seems that I am not specifying the Boot device correctly.

Hi ekorre,

I talked to my co-developer and found out that we don’t actually use that branch, we use v2.2 with a set of patches similar. I’ve uploaded them to the v2.2-LS branch on GitHub. I may have somehow broken the 2.3 branch.

Are you working over DFU? I don’t think mainline supports USB DFU, you’ll have to backport it. :frowning:

I am trying to boot over USB so that is exactly right. I tried to backport the support and while doing that I stumbled upon this


It gives detailed instructions on how to move the PMIC from I2C4 to I2C2 for the ST ATF. Works great.

Again thanks!

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Could you share your changes as a patch? Have you tested it with ST’s custom kernel?