EMMC not being detected in DFU mode

[adnan_pasha]

Hi,

We have a custom carrier board based on STM32MP157DAC. We have built a custom yocto image.

• Yocto Version: Mickledore
• Machine: stm32mp15-disco
• SoM: STM32MP157DAC
• Distro: openstlinux-weston
• Linux Kernel: 6.1.82-stm32mp-r2-r0

I was able to get a EMMC binaries by adding below line in my local.conf
STM32MP_DT_FILES_EMMC += "stm32mp157f-dk2"

I have also attached the modified flashlayout for EMMC.

I came across a post here saying if default pins are changes we will have to do otp for emmc to be detected.

below are the pins we are using:-

PB14	SDMMC2_D0
PB15	SDMMC2_D1
PB3	SDMMC2_D2
PB4	SDMMC2_D3
PA8	SDMMC2_D4
PA15	SDMMC2_D5
PC6	SDMMC2_D6
PC7	SDMMC2_D7
PE3	SDMMC2_CLK
PG6	SDMMC2_CMD

Do we need to do otp for these pins or what can be done for EMMC to be detected during dfu(0,0,0) mode for flashing to emmc.

below is my flash layout file for emmc:-

#Opt	Id	Name	Type	IP	Offset	Binary
-	0x01	fsbl-boot	Binary	none	0x0	arm-trusted-firmware/tf-a-stm32mp157f-dk2-usb.stm32
-	0x03	fip-boot	FIP	none	0x0	fip/fip-stm32mp157f-dk2-optee-emmc.bin
P	0x04	fsbl1	Binary	mmc1	boot1	arm-trusted-firmware/tf-a-stm32mp157f-dk2-optee-emmc.stm32
P	0x05	fsbl2	Binary	mmc1	boot2	arm-trusted-firmware/tf-a-stm32mp157f-dk2-optee-emmc.stm32
P	0x06	metadata1	FWU_MDATA	mmc1	0x00084000	arm-trusted-firmware/metadata.bin
P	0x07	metadata2	FWU_MDATA	mmc1	0x00100000	arm-trusted-firmware/metadata.bin
P	0x08	fip-a	FIP	mmc1	0x00180000	fip/fip-stm32mp157f-dk2-optee-emmc.bin
PED	0x09	fip-b	FIP	mmc1	0x00580000	none
PED	0x0A	u-boot-env	ENV	mmc1	0x00980000	none
P	0x10	bootfs	System	mmc1	0x00A00000	st-image-bootfs-openstlinux-weston-stm32mp15-disco.ext4
P	0x11	vendorfs	FileSystem	mmc1	0x04A00000	st-image-vendorfs-openstlinux-weston-stm32mp15-disco.ext4
P	0x12	rootfs	FileSystem	mmc1	0x05A00000	st-image-qt-openstlinux-weston-stm32mp15-disco.ext4

Thanks.

[PatrickF]

Hi @adnan_pasha 

Regarding OTP for pin changes, they are required for Boot Phase on CMD/CK and D0 pins only (only those are used by BootROM).

The pins you listed above does not need OTP fusing according to the AN5031 and wiki Boot from e•MMC™

For uBoot or else, pins are defined by Device Tree pinmux, which might miss in your case as you seems to have started your config from stm32mp157f-dk2 which does not have eMMC. 

In your case, better to look at STM32MP157D-ED1 or STM32MP157D-EV1. See https://wiki.st.com/stm32mpu/wiki/How_to_create_your_board_device_tree and https://github.com/STMicroelectronics/dt-stm32mp/tree/v5-stm32mp

For Flashlayout, please refer to Typical Flashlayout for e•MMC

Regards.

[adnan_pasha]

Hi @PatrickF 

Thanks for clarification about opt configuration.

i have made the below change in my stm32mp15xx-dkx.dtsi device tree in kernel-source and modified stm32mp157f-dk2.dts where to use sdmmc3 instead of 2.

do I need to do these coniguration in STM32MP157D-ED1 or STM32MP157D-EV1 files ?

/* changed from 3 to 2 for emmc */
&sdmmc2 {
u-boot,dm-pre-reloc;
u-boot,dm-spl;
pinctrl-names = "default", "opendrain", "sleep";

pinctrl-0 = <&sdmmc2_b4_pins_a>;
pinctrl-1 = <&sdmmc2_b4_od_pins_a>;
pinctrl-2 = <&sdmmc2_b4_sleep_pins_a>;

non-removable;
no-sd;
no-sdio;
st,neg-edge;
bus-width = <8>;
vmmc-supply = <&v3v3>;
vqmmc-supply = <&vdd>;
mmc-ddr-3_3v;
status = "okay";

};

[adnan_pasha]

Hi @PatrickF ,

With the above configuration i was able to detect emmc in linux boot.
but when trying to flash OS image to emmc from stm32cubeprogrammer it shows no device found mmc1.

thanks,

[PatrickF]

Hi,

you might miss the data 4-7 pinmux in your DT.

https://github.com/STMicroelectronics/linux/blob/v6.6-stm32mp/arch/arm/boot/dts/st/stm32mp15-pinctrl.dtsi#L1999

https://github.com/STMicroelectronics/linux/blob/v6.6-stm32mp/arch/arm/boot/dts/st/stm32mp157a-ed1.dts#L395

Regards.

[adnan_pasha]

Hi,

I had added all the 8 pins like below ,

sdmmc2_b4_pins_a: sdmmc2-b4-0 {
u-boot,dm-pre-reloc;
pins1 {
pinmux = <STM32_PINMUX('B', 14, AF9)>, /* SDMMC2_D0 */
<STM32_PINMUX('B', 15, AF9)>, /* SDMMC2_D1 */
<STM32_PINMUX('B', 3, AF9)>, /* SDMMC2_D2 */
<STM32_PINMUX('B', 4, AF9)>, /* SDMMC2_D3 */

<STM32_PINMUX('A', 8, AF9)>, /* SDMMC2_D4 */
<STM32_PINMUX('A', 15, AF9)>, /* SDMMC2_D5 */
<STM32_PINMUX('C', 6, AF10)>, /* SDMMC2_D6 */
<STM32_PINMUX('C', 7, AF10)>, /* SDMMC2_D7 */
<STM32_PINMUX('G', 6, AF10)>; /* SDMMC2_CMD */
slew-rate = <1>;
drive-push-pull;
bias-pull-up;
};
pins2 {
pinmux = <STM32_PINMUX('E', 3, AF9)>; /* SDMMC2_CK */
slew-rate = <2>;
drive-push-pull;
bias-pull-up;
};
};

sdmmc2_b4_od_pins_a: sdmmc2-b4-od-0 {
u-boot,dm-pre-reloc;
pins1 {
pinmux = <STM32_PINMUX('B', 14, AF9)>, /* SDMMC2_D0 */
<STM32_PINMUX('B', 15, AF9)>, /* SDMMC2_D1 */
<STM32_PINMUX('B', 3, AF9)>, /* SDMMC2_D2 */
<STM32_PINMUX('B', 4, AF9)>, /* SDMMC2_D3 */
<STM32_PINMUX('A', 8, AF9)>, /* SDMMC2_D4 */
<STM32_PINMUX('A', 15, AF9)>, /* SDMMC2_D5 */
<STM32_PINMUX('C', 6, AF10)>, /* SDMMC2_D6 */
<STM32_PINMUX('C', 7, AF10)>; /* SDMMC2_D7 */
slew-rate = <1>;
drive-push-pull;
bias-pull-up;
};
pins2 {
pinmux = <STM32_PINMUX('E', 3, AF9)>; /* SDMMC2_CK */
slew-rate = <2>;
drive-push-pull;
bias-pull-up;
};
pins3 {
pinmux = <STM32_PINMUX('G', 6, AF10)>; /* SDMMC2_CMD */
slew-rate = <1>;
drive-open-drain;
bias-pull-up;
};
};

sdmmc2_b4_sleep_pins_a: sdmmc2-b4-sleep-0 {
u-boot,dm-pre-reloc;
pins {
pinmux = <STM32_PINMUX('B', 14, ANALOG)>, /* SDMMC2_D0 */
<STM32_PINMUX('B', 15, ANALOG)>, /* SDMMC2_D1 */
<STM32_PINMUX('B', 3, ANALOG)>, /* SDMMC2_D2 */
<STM32_PINMUX('B', 4, ANALOG)>, /* SDMMC2_D3 */
<STM32_PINMUX('A', 8, ANALOG)>, /* SDMMC2_D4 */
<STM32_PINMUX('A', 15, ANALOG)>, /* SDMMC2_D5 */
<STM32_PINMUX('C', 6, ANALOG)>, /* SDMMC2_D6 */
<STM32_PINMUX('C', 7, ANALOG)>, /* SDMMC2_D7 */
<STM32_PINMUX('E', 3, ANALOG)>, /* SDMMC2_CK */
<STM32_PINMUX('G', 6, ANALOG)>; /* SDMMC2_CMD */
};
};

[adnan_pasha]

Hi @PatrickF ,

I would like some clarification on how modifying the Device Tree configuration impacts eMMC detection in DFU mode, given that there is no operating system running before the eMMC image is flashed. Do I need to update the Device Tree, flash the image to an SD card first, and then use that setup to flash the eMMC?

Thanks.

[PatrickF]

Hi,

during first Flashload phase, the CubeProgrammer <-> BootROM in DFU will load two images ID = 0x01 (fsbl-boot in SYSRAM) and 0x03 (fip-boot in DDR). These are not loaded in any flash, they are the supporting SW to do the real flash later. Here DT is important mostly for DDR as uboot is loaded/running from DDR.

Then this loaded FIP/uBoot is started, will reconnect to CubeProgrammer in DFU for the real external flashing phase of other partitions as listed in the Flashlayout file (CubeProgrammer <-> uBoot in DFU <-> Flash). Here Device tree is important as uBoot need to configure correctly the external flash accesses (clock, IP, pins, etc..)

You don't need to Flash SD-Card if your target is to Flash the eMMC.

Maybe share your Cubeprogrammer error message and most important the board UART console messages.

Regards.

[adnan_pasha]

Hi @PatrickF 

Thanks for the info.

Do I need to configure eMMC in the U-Boot Device Tree as well? If so, which Device Tree file should I modify?

Also, I attempted to clean and rebuild the U-Boot source, but in the process, I lost the files located at:
build-openstlinuxweston-stm32mp15-disco/tmp-glibc/work-shared/stm32mp15-disco/uboot-sources/

How can I recover these files?

Since modifying Device Tree files directly in the tmp directory isn't recommended (as they can be lost during cleans or rebuilds), what's the correct way to apply these changes from my custom layer?

I’m aware that one approach is to use patches, but when I try to generate a patch using git diff, I receive an error saying the directory is not a Git repository.

Thanks.

[adnan_pasha]

Hi @PatrickF 

I was able to get the source files back after runnning below commands

bitbake -ccleansstate <package_name>
bitbake <package_name>

Right now I'm looking into how I can modify my u-boot and tf-a device tree files from a custom layer.

Thanks.