STM32MP151aac custom board kernel not starting

Graduate II

What defconfig do you use for the kernel ? multi_v7_defconfig as mentioned in the ECO readme or the one used for u-boot ?

Which device tree, the same one from u-boot or a different customized one ?

your dts is quite close to mine but I do not use PMIC on I2C4 and your MMC2 is 4 bits wide?> In my board MMC2 is the EMMC width 8 bits

pinmux = <STM32_PINMUX('A', 8, AF9)>, /* SDMMC2_D4 */

<STM32_PINMUX('A', 9, AF10)>, /* SDMMC2_D5 */

<STM32_PINMUX('B', 3, AF9)>, /* SDMMC2_D2 */

<STM32_PINMUX('B', 4, AF9)>, /* SDMMC2_D3 */

<STM32_PINMUX('B', 14, AF9)>, /* SDMMC2_D0 */

<STM32_PINMUX('B', 15, AF9)>, /* SDMMC2_D1 */

<STM32_PINMUX('D', 3, AF9)>, /* SDMMC2_D7 */

<STM32_PINMUX('E', 5, AF9)>, /* SDMMC2_D6 */

<STM32_PINMUX('G', 6, AF10)>; /* SDMMC2_CMD */

Visitor II

The multi_v7 one, but enabled LL_Debug & earlyprintk. Same device tree as u-boot, the lab mentioned that I should do this.

Graduate II

I am now close or at the same point where you are that Linux does not start. From your git, it seems you use the Debian rootfs. My approach was using the starter package and create and bootable SD card. (The starter package can also be used to create the data on the EMMC via USB). Then update the TF-A, U-boot, Optee build artifacts and update the bootfs with the kernel uImage and uboot files. IMHO I can just use the same rootfs as it's is also based on ECO 5.0.0 For further steps in debugging I got some inspiration from this https://medium.com/@villebaillie25/how-to-debug-your-linux-bsp-fd8bcb929544

Visitor II

Well yes and no about the debian rootfs. I'd prefer to use it and tried to, but given that the issue is that the kernel can't find the rootfs, that doesn't make much difference.

Thats why rootfs used so far is the one you get from yocto (following the ST guide), thought it would be best to use ST stuff so I can get help here if it doesn't work...

Can't use a SD card yet because the carrier I made for the module hasn't got sd card slot populated.. Figured internal emmc was less error prone than external sd...

Currently tried following https://forum.digikey.com/t/debian-getting-started-with-the-stm32mp157/12459. This helps to do the building of the bootstages without the sdk, but it's for sd card.

Visitor II

Ah, didn't see that edit before:

"your dts is quite close to mine but I do not use PMIC on I2C4 and your MMC2 is 4 bits wide?> In my board MMC2 is the EMMC width 8 bits"

Hm, I used that because the dts file from Myir (module manufacturer) didn't seem to refer to 8 bits so I figure the stm32mp151 has 4bit wide. Checked datasheet of the proc and has indeed 8 bits... So check the dts again and found it did specify 8 bit afterall (must have overlooked it somehow because the pinctrl was split).

Altered the CubeMX project accordingly and rebuilding stuff etc. Shouldn't make a difference to the issue given that the bus was specified at 4 bits... But if it ends up working, it will be faster.

Update: Rebuild the yocto dist with the changes, didn't make a difference.

michiel.tjampensAuthorAnswer

Visitor II

Finally solved it. Not that I understand the why nor the how...

Reason was missing interrupt information in the pmic: stpmic@33 node...

pmic: stpmic@33 {
	...
	interrupts-extended = <&exti 55 IRQ_TYPE_EDGE_FALLING>;
	interrupt-controller;
	#interrupt-cells = <2>;
 ...
};

Why would missing interrupt info inside the pmic -that clearly is providing power- cause the emmc to not be found?

Is there somewhere a piece of code that waits for the pmic before it does anything?

@debuggingMight explain the issue you also had with pmic enabled ...

Graduate II

Greadt find. My board uses legacy, regulator power. No PMIC. I had to remove all PMIC related power from the DTs and create new DTs for regulator power. The PMIC (likely STPMIC1) uses I2C and perhaps it also uses and interrupt to the MP .and perhaps the kernel did not enable the power to EMMC ?. Just a guess..

BTW when I use mmc dev 0 ; mmc info in U-boot prompt it shows 4 bit for EMMC while the DT specifies 8 bit.. An older ECO that boots fine from EMMC also shows 4 bit for EMMC.

I am still stuck at kernel boot prompt...

Visitor II

The pmic is enabled by tf-a because u-boot is loaded from emmc. All buck's are set to always on, so doubt they go out without reason. But I gues that depends on the implementation.

Hm, mmc info here properly shows 8bit for mmc 1. So in you case mmc 0= emmc and mmc1 = sd? Because sd only goes up to 4bit.

Graduate II

Perhaps the reason is I am booting from an SD card and you boot EMMC ?

Do you use stCubeprogrammer via usb to flash the EMMC ?

Seen the capacities, MMC0=SD (16GB) and MMC1=EMMC. (4GB).

mmc dev 1
switch to partitions #0, OK
mmc1(part 0) is current device
STM32MP> mmc info
mmc info
Device: STM32 SD/MMC
Manufacturer ID: 11
OEM: 0
Name: 004GA0
Bus Speed: 52000000
Mode: MMC High Speed (52MHz)
Rd Block Len: 512
MMC version 5.0
High Capacity: Yes
Capacity: 3.7 GiB
Bus Width: 4-bit
Erase Group Size: 512 KiB
HC WP Group Size: 4 MiB
User Capacity: 3.7 GiB WRREL
Boot Capacity: 2 MiB ENH
RPMB Capacity: 512 KiB ENH
Boot area 0 is not write protected
Boot area 1 is not write protected