Hello ST Team,
I am evaluating the STM32MP215F-DK with the recommended M.2 Wi-Fi/BT module (Embedded Artists EAR00409 / Murata 2EL). I have encountered two critical issues that prevent the Wi-Fi features from working out-of-the-box with the standard Starter Package.
I believe these are bugs in the current hardware/software release.
1. Critical Software Configuration Issue: SDMMC2 Access Blocked by RIF
The STM32MP215F-DK Data Brief explicitly states that the board features an "M.2 E-Key connector to support Wi-Fi® and Bluetooth® SDIO modules". However, with the default Starter Package (OpenSTLinux 6.6), the Linux kernel fails to probe the Wi-Fi module on SDMMC2.
Symptoms:
• Linux kernel log shows no response from mmc1 (SDMMC2).
• Attempting to access the SDMMC2 registers manually via devmem 0x48230000 results in a Bus Error.
• OP-TEE console reports a firewall exception: SERC exception ID: 77 (SDMMC2 Illegal Access).
Root Cause Analysis: It appears that the Trusted Firmware-A (TF-A) device tree in the provided images configures the RIF (Resource Isolation Framework) for SDMMC2 as Secure World only(RIF_SEC). This prevents the Linux kernel (Non-Secure World) from accessing the peripheral, rendering the M.2 slot unusable for Wi-Fi in the default configuration.
Workaround Verified: I had to modify the TF-A device tree source (fdts/stm32mp215f-dk.dts) to change the st,protreg property of the &sdmmc2 node to RIF_NSEC (Non-Secure). After recompiling and flashing TF-A, Linux could successfully access the registers and load the Wi-Fi driver.
Request: Please update the default TF-A configuration in the next OpenSTLinux Starter Package to allow Non-Secure access to SDMMC2 by default, matching the board's advertised capabilities.
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2. Hardware Errata: U19 Level Shifter Connection
I also noted in UM3571 (Rev 2, Section 10.3) that there is a known limitation on the MB2059-MP215F-B02 board:
"M.2 E-Key WAKE signals cannot be controlled by an I/O due to an incorrect connection of the U19 (DNF) level shifter."
Question: Could you clarify the impact of this errata on the Murata 2EL (IW612) module's power management? Specifically, does this disconnection prevent the host from controlling WL_HOST_WAKE / BT_HOST_WAKE? Are there any recommended hardware workarounds (e.g., fly wires) for developers who need to test Low-Power modes with Wi-Fi?
Thank you for your support.
System Info:
• Board: STM32MP215F-DK (MB2059-MP215F-B02)
• Module: Embedded Artists EAR00409 (Murata 2EL / NXP IW612)
• SW Version: STM32MP2 OpenSTLinux 6.6 Yocto Scarthgap (v25.06.11)
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References: STM32MP215F-DK Data brief, Features. UM3571 User manual, Section 10.3 Board revision history.
