AM623: about boot from emmc

hao teng

Part Number: AM623

Tool/software:

Using our own AM623 board, the SD card can start normally, but it cannot start when using EMMC. The program in EMMC is programmed through script burning after starting from an SD card. The attachment contains the script for burning and running screenshots

this is sh

#!/bin/bash

set -e

# Major version
MAJOR_VERSION="4"
# Minor version
MINOR_VERSION="1"

# eMMC device
EMMC_DEVICE=/dev/mmcblk0

# SD device
SD_DEVICE=/dev/mmcblk1

# SD mount point
SD_MOUNT_POINT=/run/media/mmcblk1

# eMMC default unit size (1024 * 1024 = 1048576Byte = 1MB)
SIZE_MB=$((1024 * 1024))

# eMMC boot partition size (128MB)
EMMC_BOOT_PART_SIZE=$((128 * 1024 * 1024))

# The reserved capacity of rootfs partition is 800MB
# Since inode also takes up space, the actual free space is insufficient for 800MB.
ROOTFS_RESERVE_SIZE=$((800 * 1024 * 1024))

# Print error log
function err() {
echo "[$(date +'%Y-%m-%dT%H:%M:%S%z')]: $@" >&2
}

# Check the SD card is mounted
function check_sdboot_mount() {
if [[ ! -e ${SD_DEVICE} ]]; then
err "ERROR! Can not find SD."
err "Abort, work not done!"
exit 1
fi

sdboot_mount_status=$(df ${SD_DEVICE}p1 | grep ${SD_DEVICE}p1 | awk '{print $6}')
if [[ -z ${sdboot_mount_status} ]]; then
err "ERROR! ${SD_DEVICE}p1 not mounted."
err "Abort, work not done!"
exit 1
fi

sdboot_mount_status=$(df ${SD_DEVICE}p3 | grep ${SD_DEVICE}p3 | awk '{print $6}')
if [[ -z ${sdboot_mount_status} ]]; then
err "ERROR! ${SD_DEVICE}p3 not mounted."
err "Abort, work not done!"
exit 1
fi

echo "SD card is mounted."
}

# Check emmc device is exist.
function check_emmc_device() {
# Check whether the eMMC device exists
if [[ ! -b ${EMMC_DEVICE} || -z ${EMMC_DEVICE} ]]; then
err "ERROR: ${EMMC_DEVICE} is not exist."
err "Abort, work not done!"
exit 1
fi

echo "eMMC device is exist."

# Check whether the EMMC capacity is sufficient
# Calculate eMMC and filesystem size
emmc_size=$(($(fdisk -s ${EMMC_DEVICE}) * 1024))
fs_size=$(($(du -s ${SD_MOUNT_POINT}p3 | awk '{print $1}') * 1024))

# The eMMC capacity must be larger than the size of the filesystem
if [[ $(($emmc_size - $EMMC_BOOT_PART_SIZE)) -lt ${fs_size} ]]; then
err "ERROR: Create eMMC partition failed, The eMMC capacity is not sufficient!"
exit 1
fi

echo "eMMC capacity is satisfied."
}

# Create emmc partition
function create_emmc_partition() {
echo "Partitioning ${EMMC_DEVICE}..."

# umount them in case mounted already.
for i in $(cat /proc/mounts | grep ${EMMC_DEVICE}p | awk '{print $1}'); do
umount $i 2>/dev/null
done

# Clear the head of emmc.
dd if=/dev/zero of=${EMMC_DEVICE} bs=1024 count=1024

# Divide boot partition
partition_start=1
partition_end=$((${EMMC_BOOT_PART_SIZE} / ${SIZE_MB} + ${partition_start}))

parted -s ${EMMC_DEVICE} mklabel msdos
parted -s ${EMMC_DEVICE} unit MiB mkpart primary fat32 -- ${partition_start} ${partition_end}
parted -s ${EMMC_DEVICE} set 1 boot on

# Divide rootfs partition
# The rootfs partition is twice the size of the filesystem
partition_start=${partition_end}
partition_end=$(($((${fs_size} + ${ROOTFS_RESERVE_SIZE})) / ${SIZE_MB} + ${partition_start}))

if [[ $(($emmc_size - $EMMC_BOOT_PART_SIZE)) -lt $((${fs_size} + ${ROOTFS_RESERVE_SIZE})) ]]; then
# If the rootfs partition cannot reserve 800MB of free space,
# a warning prompt is printed, but it can be flash normally.
err "WARNING: Due to insufficient eMMC space, The rootfs partition cannot reserve 800MB of space."

# Since the rootfs partition cannot be divided into twice the free space,
# all the remaining space in the emmc is divided into the rootfs partition.
partition_end=-2
fi

parted -s ${EMMC_DEVICE} unit MiB mkpart primary ext4 -- ${partition_start} ${partition_end}
sleep 15 #FIXME Make sure partition emmc is finished

# Format partition
partition_list=(${EMMC_DEVICE}p1 ${EMMC_DEVICE}p2)

for partition in ${partition_list[*]}; do
mount_state=$(cat /proc/mounts | grep ${partition} | awk '{print $1}')

# Umount in case mounted alraady
if [[ ! -z "${mount_state}" ]]; then
umount ${partition}
fi
done

mkfs.vfat -F 32 -n BOOT ${partition_list[0]}
sleep 1

mkfs.ext4 -F -L rootfs ${partition_list[1]}
sleep 1

echo "Partition done!"
}

# Check that the environment is satisfied
function check_environment() {
echo "Checking flash environment..."

# Check the SD card is mounted
check_sdboot_mount

# Check emmc device is exist
check_emmc_device

echo "Check flash environment done."
}

# Get MTD partition
function get_mtd_partition() {
mtd_partition=$(cat /proc/mtd | grep $1 | awk -F ':' '{print $1}' | awk -F 'mtd' '{print $2}')
if [[ -z "${mtd_partition}" ]]; then
err "ERROR! Get MTD partition number of $1 failed!"
err "Abort, work not done!"
exit 1
fi
echo ${mtd_partition}
}

# Erase u-boot environment variable
function erase_uboot_env() {
local emmc_boot_partition="${EMMC_DEVICE}boot0"
local profile="/sys/block/mmcblk0boot0/force_ro"

echo "Erasing u-boot environment variable..."

if [[ ! -e ${profile} ]]; then
err "ERROR: ${profile} is not exist."
exit 1
fi

if [[ ! -e ${emmc_boot_partition} ]]; then
err "ERROR: ${emmc_boot_partition} is not exist."
exit 1
fi

# Enable to can write the boot partition
echo 0 > ${profile}

# Erase environment variable
# ENV_SIZE: 0x20000
# ENV_OFFSET: 0x380000
dd if=/dev/zero of=${emmc_boot_partition} bs=1k count=128 seek=3584

echo "Erase u-boot environment variable done."
}

# Flash u-boot/dtb/kernel/rootfs
function flash_system() {
local emmc_boot_partition="${EMMC_DEVICE}boot0"
local profile="/sys/block/mmcblk0boot0/force_ro"

echo "Flashing system..."

# Flash u-boot
echo "-> Flashing tiboot3/tispl/u-boot..."

# Enable to can write the boot partition
echo 0 > ${profile}

# Flash tiboot3.bin
dd if=/media/mmcblk1p1/tiboot3.bin of=${emmc_boot_partition} bs=1K
# Flash tispl.bin
dd if=/media/mmcblk1p1/tispl.bin of=${emmc_boot_partition} bs=1K seek=512
# Flash u-boot.img
dd if=/media/mmcblk1p1/u-boot.img of=${emmc_boot_partition} bs=1K seek=1536

echo "-> Flash tiboot3/tispl/u-boot done."

echo "-> Flashing dtb/kernel/rootfs to ${EMMC_DEVICE}p2..."

# Mount points of rootfs partition.
local rootfs_mount_point="/tmp/$$-rootfs"

if [[ ! -d ${rootfs_mount_point} ]]; then
mkdir -p ${rootfs_mount_point}
fi
mount ${EMMC_DEVICE}p2 ${rootfs_mount_point}

# Copy file to dtb/kernel/rootfs from backup partition of SD
sd_p3_mount_point=$(df ${SD_DEVICE}p3 | grep ${SD_DEVICE}p3 | awk '{print $6}')
cp -rf ${sd_p3_mount_point}/. ${rootfs_mount_point}

# Umount rootfs partition
rootfs_partition=$(cat /proc/mounts | grep ${EMMC_DEVICE}p2 | awk '{print $1}')
if [[ ! -z "${rootfs_partition}" ]]; then
umount ${EMMC_DEVICE}p2
fi

echo "-> Flash dtb/kernel/rootfs done."

echo "Flash system done."
}

######### MAIN ENTRANCE#########
function main() {

echo -e "\nVersion: mkemmcboot_${MAJOR_VERSION}.${MINOR_VERSION}"

# Check the flash environment
echo -e "\n1/4:"
check_environment

# Erases the u-boot environment variable
echo -e "\n2/4:"
erase_uboot_env

# Create emmc partition
echo -e "\n3/4:"
create_emmc_partition

# Flash u-boot/kernel/rootfs etc
echo -e "\n4/4:"
flash_system

sync

}

main

9 months ago

0 Prashant Shivhare 9 months ago

TI__Guru* 76491 points

Hello,

Please refer to the following guide for flashing Linux to eMMC using SD card:

https://dev.ti.com/tirex/explore/node?node=A__AdNWBqCVds4ZSqU9osT1tQ__AM62-ACADEMY__uiYMDcq__LATEST

For your own script, please make sure you are following each step listed in the above guide. More specifically, make sure to run the "mmc partconf" and "mmc bootbus" commands from the U-Boot.

Regards,

Prashant

0 hao teng 9 months ago in reply to Prashant Shivhare

Intellectual 380 points

I can write using the uboot command, but my u-boot.img file is too large, causing the download to fail.

0 Prashant Shivhare 9 months ago in reply to hao teng

TI__Guru* 76491 points

Hello,

Please see the following thread:

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1494767/am6442-emmc-boot-spl-failed-to-boot-from-all-boot-devices

Regards,

Prashant

0 hao teng 9 months ago in reply to Prashant Shivhare

Intellectual 380 points

I modified the defconfig of A53 to load the u-boot.img address from 0x1400 to 0xc00, but during the process of burning u-boot.img to EMMC, there was a problem as shown in the diagram. My file only has 890KB and does not exceed 4MB. My understanding is that there may be loading issues during the loading process, but executing mmc write ${loadaddr} 0x1400 0x2000 should result in normal writing.

0 hao teng 9 months ago in reply to Prashant Shivhare

Intellectual 380 points

Is it possible to configure MMC partconf 0 1 1 ，mmc bootbus 0 2 0 0，in the Linux user phase

0 Prashant Shivhare 9 months ago in reply to hao teng

TI__Guru* 76491 points

hao teng said:
but executing mmc write ${loadaddr} 0x1400 0x2000 should result in normal writing.

If the A53 U-Boot is just 1MB then you may use the following command:

=> mmc write $loadaddr 0x1400 0x800

hao teng said:
Is it possible to configure MMC partconf 0 1 1 ，mmc bootbus 0 2 0 0，in the Linux user phase

These commands are meant to be run from the U-Boot.

0 hao teng 9 months ago in reply to Prashant Shivhare

Intellectual 380 points

Hi
I understand that the size of the boot0 partition is determined by my emmc, and the size of the mmc write command is set incorrectly. Thank you very much for your help.
Can I find a way to configure partconf and bootbus in the Linux application layer?Because I want to implement EMMC from SD card burning on Linux layer, if I still need to enter U-boot layer configuration, I need to restart the device and modify the U-boot code.

+1 Prashant Shivhare 9 months ago in reply to hao teng

TI__Guru* 76491 points

Hi, I will check if there is a way from Linux and get back to you.

+1 Prashant Shivhare 9 months ago in reply to Prashant Shivhare

TI__Guru* 76491 points

hao teng said:
Can I find a way to configure partconf and bootbus in the Linux application layer?

You may use the following commands from the "mmc-utils" userspace application:

https://git.kernel.org/pub/scm/utils/mmc/mmc-utils.git/tree/man/mmc.1#n56

https://git.kernel.org/pub/scm/utils/mmc/mmc-utils.git/tree/man/mmc.1#n62

Sample logs:

root@am62pxx-evm:/run/media/root-mmcblk1p2/usr/bin# ./mmc bootpart enable 1 1 /dev/mmcblk0
root@am62pxx-evm:/run/media/root-mmcblk1p2/usr/bin# ./mmc bootbus set single_backward x1 x8 /dev/mmcblk0
Changing ext_csd[BOOT_BUS_CONDITIONS] from 0x02 to 0x02

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AM623: about boot from emmc