DESK-MX6UL-L/Development/How to create a bootable microSD card
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How to create a bootable SD card[edit | edit source]
 The procedure described here was tested with a virtual machine such as the MVM. The USB controller of the MVM should be enabled by default. If you are using Linux-based distribution and are having trouble detecting a USB device in virtual machine, please make sure your user belongs to the vboxusers group. |
This article shows how to create a bootable microSD for the DESK-MX6UL-L Release Notes kit by using a simple bash script.
Note: Note: Starting from DESK-MX6UL-L 1.0.1 release the support for the SPL has been introduced in U-Boot. Previous versions of this script will no longer produce a fully functional and bootable microSD card.
The procedure has been tested on a MVM released with DESK-MX6UL-L 4.0.1 release with
- a 32 GB microSD card [1]
- a USB SD card reader
- the binary files delivered along with the DESK-MX6UL-L 4.0.0
The resulting card is partitioned as depicted here below:
- bootable partition (mmcblk0p1, vfat) containing:
- binary images (U-Boot and kernel images)
- root file system partition (mmcblk0p2, ext3)
- root file system binaries and init scripts
The script - named mksd.sh - can be realized with the following code:
#!/bin/bash
if [[ -z $1 || -z $2 || -z $3 || -z $4 || -z $5 ]]
then
echo "$0 Usage:"
echo " $0 <device> <u-boot.img> <SPL> <binaries directory> <rootfs tar.bz2>"
echo " Example: $0 /dev/sdc u-boot.img SPL binaries/ rootfs.tar.bz2"
exit
fi
if [ "$(whoami)" != "root" ]
then
echo "you must be root to run this script!"
exit
fi
if ! [[ -b $1 ]]
then
echo "$1 is not a valid block device!"
exit
fi
if ! [[ -e $2 ]]
then
echo "Incorrect u-boot.img location!"
exit
fi
if ! [[ -e $3 ]]
then
echo "Incorrect SPL location!"
exit
fi
if ! [[ -d $4 ]]
then
echo "Incorrect Binaries location!"
exit
fi
if ! [[ -f $5 ]]
then
echo "Incorrect rootfs location!"
exit
fi
DRIVE=$1
if [[ "$DRIVE" == *"mmcblk"* ]]
then
echo "You're using a mmc device, I need to fix partition names"
PART="p"
else
PART=""
fi
UBOOT=$2
SPL=$3
BINARIES=$4
RFS=$5
echo "All data on "$DRIVE" now will be destroyed! Continue? [y/n]"
read ans
if ! [ $ans == 'y' ]
then
exit
fi
echo "[Partitioning $1...]"
dd if=/dev/zero of=$DRIVE bs=1024 count=1024
SIZE=`fdisk -l $DRIVE | grep Disk | awk '{print $5}'`
echo DISK SIZE - $SIZE bytes
CYLINDERS=`echo $SIZE/255/63/512 | bc`
# check if we're running an old (e.g. 2.20.x) or new (e.g. 2.24.x) sfdisk
sfdisk --help | grep -- -H
if [ "$?" -eq "0" ]
then
{
echo 40,1380,0x0c,*
echo 1420,,83,-
} | sfdisk -D -H 255 -S 63 -C $CYLINDERS $DRIVE
else
{
echo 16M,8176M,0x0c,*
echo 8192M,,83,-
} | sfdisk $DRIVE
fi
partprobe
echo "[Making filesystems...]"
mkfs.vfat -F 32 -n BOOT "$DRIVE$PART"1 #> /dev/null
mkfs.ext3 -F -L ROOTFS "$DRIVE$PART"2 #> /dev/null
# wait for the VM to recognize the uSD
sleep 60
echo "[Copying files...]"
binaries_dir=${BINARIES%/}
mount "$DRIVE$PART"1 /mnt
cp -av --no-preserve=ownership $binaries_dir/* /mnt/
umount "$DRIVE$PART"1
echo "[Extracting rfs (this may take a while...)]"
mount "$DRIVE$PART"2 /mnt
tar jxf $RFS -C /mnt > /dev/null
chmod 755 /mnt
umount "$DRIVE$PART"2
echo "[Programming SPL]"
dd if=$SPL of=$DRIVE bs=512 seek=2 conv=fsync
echo "[Programming u-boot.img]"
dd if=$UBOOT of=$DRIVE bs=1k seek=69 conv=fsync
echo "[Done]"
Here is an example that shows how to use this script. We use here files delivered with DESK-MX6UL-L 4.0.0 release. Before invoking the script, the following files has to be renamed in order to make them compatible with the default U-Boot environment variables:
- bootscript:
boot.scr - splash image:
splash_image.bmp - Linux kernel:
desk-mx6ul-l-4.0.0_uImage - Device tree blob:
desk-mx6ul-l-4.0.0_imx6ul-axelulite-cb003a.dtb.
In the case of you don't have some file on MVM, please download it from mirro.dave.eu.
We will copy them into ~/desk-mx-l/desk directory. Needed binary files can be found on MVM in the following location:
dvdk@vagrant:~$ ll /tftpboot/desk-mx6ul-l/ total 11352 -rw-r--r-- 1 dvdk root 32964 Mar 31 11:01 desk-mx6ul-l-4.0.0-imx6ul-axelulite-cb003a.dtb -rw-r--r-- 1 dvdk root 32002 Mar 31 11:01 desk-mx6ul-l-4.0.0-imx6ul-axelulite-cb006c.dtb -rw-r--r-- 1 dvdk root 33028 Mar 31 11:01 desk-mx6ul-l-4.0.0-imx6ul-lynx-som0013-cb002f.dtb -rw-r--r-- 1 dvdk root 8017976 Mar 31 11:01 desk-mx6ul-l-4.0.0-uImage -rw-r--r-- 1 dvdk root 35840 Mar 31 10:59 desk-mx6ul-l-4.0.0-mx6uldesk_axelulite_SPL -rw-r--r-- 1 dvdk root 48128 Mar 31 10:59 desk-mx6ul-l-4.0.0-mx6uldesk_axelulite_spi_SPL -rw-r--r-- 1 dvdk root 552184 Mar 31 11:00 desk-mx6ul-l-4.0.0-mx6uldesk_axelulite_spi_u-boot.img -rw-r--r-- 1 dvdk root 551704 Mar 31 10:59 desk-mx6ul-l-4.0.0-mx6uldesk_axelulite_u-boot.img -rw-r--r-- 1 dvdk root 35840 Mar 31 10:59 desk-mx6ul-l-4.0.0-mx6uldesk_lynx_SPL -rw-r--r-- 1 dvdk root 48128 Mar 31 10:59 desk-mx6ul-l-4.0.0-mx6uldesk_lynx_spi_SPL -rw-r--r-- 1 dvdk root 517248 Mar 31 10:59 desk-mx6ul-l-4.0.0-mx6uldesk_lynx_spi_u-boot.img -rw-r--r-- 1 dvdk root 516776 Mar 31 10:59 desk-mx6ul-l-4.0.0-mx6uldesk_lynx_u-boot.img -rw-r--r-- 1 dvdk root 1152054 Mar 31 10:59 splash_image.bmp dvdk@vagrant:~$ mkdir -p ~/desk-mx-l/desk dvdk@vagrant:~$ cp /tftpboot/desk-mx6ul-l/desk-mx6ul-l-4.0.0_uImage ~/desk-mx-l/desk/desk-mx6ul-l-4.0.0_uImage dvdk@vagrant:~$ cp /tftpboot/desk-mx6ul-l/desk-mx6ul-l-4.0.0_imx6ul-axelulite-cb003a.dtb ~/desk-mx-l/desk/desk-mx6ul-l-4.0.0_imx6ul-axelulite-cb003a.dtb dvdk@vagrant:~$ cp /tftpboot/desk-mx6ul-l/splash_image.bmp ~/desk-mx-l/desk/ dvdk@vagrant:~$ cp ~/desk-mx-l/boot.scr ~/desk-mx-l/desk/boot.scr dvdk@vagrant:~$ cp ~/desk-mx-l/rfs/desk-mx6ul-l-4.0.0_modules.tar.gz ~/desk-mx-l/desk/
You can now run the script, by passing the following parameters:
- Device file of the microSD card (
/dev/sdbin the example) - U-Boot image
- SPL
- Path of the directory containing the bootscript file, the Linux kernel image, and the device tree blob files
- Archive of the target's root file system (compressed as
.tar.bz2file).
dvdk@vagrant:~/desk-mx-l$ sudo umount /dev/sdb*
dvdk@vagrant:~/desk-mx-l$ sudo ./desk-mx6ul-l-4.0.1_mksd.sh /dev/sdb /tftpboot/desk-mx6ul-l/desk-mx6ul-l-4.0.0_mx6uldesk_axelulite_u-boot.img /tftpboot/desk-mx6ul-l/desk-mx6ul-l-4.0.0_mx6uldesk_axelulite_SPL ~/desk-mx-l/desk ./rfs/desk-mx6ul-l-4.0.1_dave-image-devel-desk-mx6ul.tar.bz2
All data on /dev/sdb now will be destroyed! Continue? [y/n]
y
[Partitioning /dev/sdb...]
1024+0 records in
1024+0 records out
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.262305 s, 4.0 MB/s
DISK SIZE - 31002198016 bytes
Checking that no-one is using this disk right now ... OK
Disk /dev/sdb: 28.89 GiB, 31002198016 bytes, 60551168 sectors
Disk model: Transcend
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
>>> Created a new DOS disklabel with disk identifier 0x937180d6.
/dev/sdb1: Created a new partition 1 of type 'W95 FAT32 (LBA)' and of size 8 GiB.
/dev/sdb2: Created a new partition 2 of type 'Linux' and of size 20.9 GiB.
/dev/sdb3: Done.
New situation:
Disklabel type: dos
Disk identifier: 0x937180d6
Device Boot Start End Sectors Size Id Type
/dev/sdb1 * 32768 16777215 16744448 8G c W95 FAT32 (LBA)
/dev/sdb2 16777216 60551167 43773952 20.9G 83 Linux
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
[Making filesystems...]
mkfs.fat 4.1 (2017-01-24)
mke2fs 1.45.5 (07-Jan-2020)
/dev/sdb2 contains a ext3 file system labelled 'ROOTFS'
created on Mon Apr 3 10:19:52 2023
Creating filesystem with 5471744 4k blocks and 1368064 inodes
Filesystem UUID: a0208180-9d1c-47e8-a8e0-c92a63a7059a
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
[Copying files...]
'/home/dvdk/desk-mx-l/desk/boot.scr' -> '/mnt/boot.scr'
'/home/dvdk/desk-mx-l/desk/desk-mx6ul-l-4.0.0_imx6ul-axelulite-cb003a.dtb' -> '/mnt/desk-mx6ul-l-4.0.0_imx6ul-axelulite-cb003a.dtb'
'/home/dvdk/desk-mx-l/desk/desk-mx6ul-l-4.0.0_uImage' -> '/mnt/desk-mx6ul-l-4.0.0_uImage'
'/home/dvdk/desk-mx-l/desk/splash_image.bmp' -> '/mnt/splash_image.bmp'
[Extracting rfs (this may take a while...)]
[Programming SPL]
70+0 records in
70+0 records out
35840 bytes (36 kB, 35 KiB) copied, 0.0120358 s, 3.0 MB/s
[Programming u-boot.img]
538+1 records in
538+1 records out
551704 bytes (552 kB, 539 KiB) copied, 0.164175 s, 3.4 MB/s
[Done]
[1] In case you have a different size, you'll need to change the sfdisk parameters accordingly.
bootscr[edit | edit source]
Once you got the new binaries compiled from your modified sources, they have to be installed on first SD partition preserving the original file names used into boot.scr U-Boot bootscript.
Here below there is an example on how to create a boot.scr file from the bootscript.txt for booting from SD card:
echo 'bootscript generated with command "mkimage -A ARM -T script -C none -n DESK-MX6UL -d bootscript.txt boot.scr"'
setenv desk_release 'desk-mx6ul-l-4.0.0'
if test 0x${som_configid#} = 0x00000013 && test 0x${cb_configid#} = 0x0000002f;
then
setenv fdtfile ${desk_release}_imx6ul-lynx-som0013-cb002f.dtb
elif test 0x${cb_configid#} = 0x0000003a
then
setenv fdtfile ${desk_release}_imx6ul-axelulite-cb003a.dtb
elif test 0x${cb_configid#} = 0x0000006c
then
setenv fdtfile ${desk_release}_imx6ul-axelulite-cb006c.dtb
else
echo Invalid CB! Autoreset ...
sleep 30
reset
fi
setenv bootfile ${desk_release}_uImage
setenv mmc_loadk 'fatload mmc ${mmcdev}:1 ${loadaddr} ${bootfile}'
setenv mmc_loadfdt 'fatload mmc ${mmcdev}:1 ${fdtaddr} ${fdtfile}'
echo Booting DESK-MX6UL via mmcboot with ${fdtfile} as device tree
run mmcboot
echo mmcboot FAILURE
and compile it using:
mkimage -A ARM -T script -C none -n DESK-MX6UL -d bootscript.txt boot.scr
Then copy the boot.scr into the <binaries_dir> directories used by the script to create the SD card.
Install Module[edit | edit source]
To install kernel modules, follow the steps below.
root@desk-mx6ul-axelulite:~# sudo mount /dev/mmcblk0p1 /media root@desk-mx6ul-axelulite:~# tar xvzf /media/desk-mx6ul-l-4.0.0_modules.tar.gz -C /
After installation, run the following command to verify that the installation was successful:
root@desk-mx6ul-axelulite:~# ls -l /lib/modules/$(uname -r) total 300 lrwxrwxrwx 1 541 502 65 Apr 3 2023 build -> /home/jenkins/workspace/workspace/DESK-MX6UL-L-4.x.x_Linux-kernel drwxr-xr-x 6 541 502 4096 Apr 3 2023 kernel -rw-r--r-- 1 541 502 2718 Apr 3 2023 modules.alias -rw-r--r-- 1 541 502 4768 Apr 3 2023 modules.alias.bin -rw-r--r-- 1 541 502 14878 Apr 3 2023 modules.builtin -rw-r--r-- 1 541 502 34704 Apr 3 2023 modules.builtin.alias.bin -rw-r--r-- 1 541 502 17778 Apr 3 2023 modules.builtin.bin -rw-r--r-- 1 541 502 105373 Apr 3 2023 modules.builtin.modinfo -rw-r--r-- 1 541 502 10689 Apr 3 2023 modules.dep -rw-r--r-- 1 541 502 21666 Apr 3 2023 modules.dep.bin -rw-r--r-- 1 541 502 0 Apr 3 2023 modules.devname -rw-r--r-- 1 541 502 8657 Apr 3 2023 modules.order -rw-r--r-- 1 541 502 85 Apr 3 2023 modules.softdep -rw-r--r-- 1 541 502 16970 Apr 3 2023 modules.symbols -rw-r--r-- 1 541 502 23964 Apr 3 2023 modules.symbols.bin lrwxrwxrwx 1 541 502 65 Apr 3 2023 source -> /home/jenkins/workspace/workspace/DESK-MX6UL-L-4.x.x_Linux-kernel
