Won’t boot from eMMC

[BillR]

Our custom board is based off the Red board.
eMMC works in general, but can’t boot off it, only SD card.
Our TF-A device tree has the same definitions as Red Board’s device tree for sdmmc2.

Using these trusted boot images which work fine when used for SD card boot:
fsbl1 = tf-a.stm32
fsbl2 = tf-a.stm32
ssbl = u-boot.stm32

I have followed the procedure from the relevant readme’s such as:
https://github.com/ARM-software/u-boot/blob/master/board/st/stm32mp1/README,
using Step 7 “Prepare SD card” but instead doing it to /dev/mmcblk2 for eMMC while running off SD card.

Our chip is Rev Z, which I understand fixes a eMMC boot errata. Our eMMC is Micron 16GB.

[BillR]

eMMC info from u-boot, in case its of use:

OSD32MP> mmc dev 1
switch to partitions #0, OK
mmc1(part 0) is current device
OSD32MP> mmc info
Device: STM32 SD/MMC
Manufacturer ID: 13
OEM: 14e
Name: S0J56
Bus Speed: 52000000
Mode: MMC High Speed (52MHz)
Rd Block Len: 512
MMC version 5.1
High Capacity: Yes
Capacity: 14.8 GiB
Bus Width: 8-bit
Erase Group Size: 512 KiB
HC WP Group Size: 8 MiB
User Capacity: 14.8 GiB WRREL
Boot Capacity: 31.5 MiB ENH
RPMB Capacity: 4 MiB ENH

[BillR]

I followed directions to instead do it from u-boot and it will boot now.
I was unaware that eMMC has some dedicated boot partitions.

a) prepare GPT on eMMC,
example with 2 partitions, bootfs and rootfs:

# setenv emmc_part “name=ssbl,size=2MiB;name=bootfs,type=linux,bootable,size=64MiB;name=rootfs,type=linux,size=512”
# gpt write mmc 1 ${emmc_part}

b) copy SPL on eMMC on first boot partition
(SPL max size is 256kB, with LBA 512, 0x200)

# ext4load mmc 0:4 0xC0000000 tf-a.stm32
# mmc dev 1
# mmc partconf 1 1 1 1
# mmc write ${fileaddr} 0 200
# mmc partconf 1 1 1 0

b) copy U-Boot in first GPT partition of eMMC

# ext4load mmc 0:4 0xC0000000 u-boot.stm32
# mmc dev 1
# part start mmc 1 1 partstart
# part size mmc 1 1 partsize
# mmc write ${fileaddr} ${partstart} ${partsize}

To boot from eMMC, select BootPinMode = 0 1 0 and reset.

[Neeraj Dantu]

BillR,

Glad you are able to resolve your problem. As you indicated, eMMC and SD card have different partition layouts. Please see https://wiki.st.com/stm32mpu-ecosystem-v2/wiki/STM32CubeProgrammer_flashlayout for reference.

Best,
Neeraj

[Author]

Posts