DESK-MX6UL-L/Deployment/Standalone boot
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| Issue Date | Notes | ||
| First DESK-MX6UL-L release | |||
| DESK-MX6UL-L 3.0.0 release | |||
| DESK-MX6UL-L 4.0.0 release | |||
| 2025/12/17 | DESK-MX6UL-L 6.0.0 release | ||
Contents
Standalone boot[edit | edit source]
Introduction[edit | edit source]
This document was written and tested with the software/hardware combination described in the history table above. However, it contains general concepts that can be adapted on any DAVE Embedded Systems' Linux platform.
 The following programming examples are intended for laboratory usage or for preliminary deployment strategy. |
We'll explain how to program and configure a <SOM> to boot in standalone mode, without the need of a system microSD card or an NFS server, with two options:
- booting with NOR and NAND internal storage
- in this configuration the primary boot images will be fetched from NOR flash storage, while the root file system will be fetched from NAND flash
Program boot images into NOR flash[edit | edit source]
U-Boot[edit | edit source]
Update to the latest U-Boot version allows usage of u-boot environment variables available.
=> run load_spl
Using ethernet@2188000 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.90
Filename 'desk-mx6ul-l/SPL'.
Load address: 0x80800000
Loading: #############
248 KiB/s
done
Bytes transferred = 64512 (fc00 hex)
=> run spi_update
spi_update_spl spi_update_uboot spi_updatefdt spi_updatek spi_updatesplash
=> run spi_update_spl
SF: Detected is25lp128 with page size 256 Bytes, erase size 64 KiB, total 16 MiB
SF: 65536 bytes @ 0x0 Erased: OK
device 0 offset 0x400, size 0xfc00
SF: 64512 bytes @ 0x400 Written: OK
=> run load_uboot
Using ethernet@2188000 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.90
Filename 'desk-mx6ul-l/u-boot.img'.
Load address: 0x80800000
Loading: #################################################################
#################################################################
##########################
268.6 KiB/s
done
Bytes transferred = 794660 (c2024 hex)
=> run spi_update_uboot
SF: Detected is25lp128 with page size 256 Bytes, erase size 64 KiB, total 16 MiB
SF: 851968 bytes @ 0x10000 Erased: OK
device 0 offset 0x10000, size 0xc2024
SF: 794660 bytes @ 0x10000 Written: OK
=>
kernel image and device tree[edit | edit source]
We assume that the environment variables in U-Boot are properly configured:
env default spi_loadk env default spi_loadfdt env default spi_updatek env default spi_updatefdt env default spi_nand saveenv
- Update the
bootfileandfdtfileenvironment variables to fit the filename as found inside the TFTP server. - Program kernel and device tree on NOR flash with the following U-Boot command
sf probe; run loadk spi_updatek loadfdt spi_updatefdt
E.g.:
=> run loadk spi_updatek loadfdt spi_updatefdt
Using ethernet@2188000 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.90
Filename 'desk-mx6ul-l/uImage'.
Load address: 0x80800000
Loading: #################################################################
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#################
267.6 KiB/s
done
Bytes transferred = 10401080 (9eb538 hex)
SF: 11534336 bytes @ 0x200000 Erased: OK
device 0 offset 0x200000, size 0x9eb538
SF: 10401080 bytes @ 0x200000 Written: OK
Using ethernet@2188000 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.90
Filename 'desk-mx6ul-l/imx6ul-axelulite-cb003a.dtb'.
Load address: 0x83000000
Loading: #######
209 KiB/s
done
Bytes transferred = 32964 (80c4 hex)
SF: 524288 bytes @ 0x180000 Erased: OK
device 0 offset 0x180000, size 0x80c4
SF: 32964 bytes @ 0x180000 Written: OK
=>
then save the new boot configuration from SPI:
=> setenv bootcmd run spi_nand => saveenv
Program root file system into NAND flash[edit | edit source]
- boot the system via SD or NFS as described in the Booting from NFS
- by default, the NAND is already partitioned to allow booting from NAND-only (see next section) and, thus, some partitions are reserved for u-boot and kernel images. Here we won't modify this default configuration. The MTD partitions can be dumped with
/proc/mtd(the partition's name should be self-explanatory)
root@desk-mx6ul-axelulite:~# cat /proc/mtd dev: size erasesize name mtd0: 00200000 00080000 "nand-SPL" mtd1: 00600000 00080000 "nand-uboot" mtd2: 00100000 00080000 "nand-env1" mtd3: 00100000 00080000 "nand-env2" mtd4: 00100000 00080000 "nand-fdt" mtd5: 00100000 00080000 "nand-spare" mtd6: 00c00000 00080000 "nand-kernel" mtd7: 00400000 00080000 "nand-splash" mtd8: 7e400000 00080000 "nand-ubi" mtd9: 00010000 00010000 "spi-SPL" mtd10: 000f0000 00010000 "spi-uboot" mtd11: 00040000 00010000 "spi-env1" mtd12: 00040000 00010000 "spi-env2" mtd13: 00080000 00010000 "spi-dtb" mtd14: 00b00000 00010000 "spi-kernel" mtd15: 00200000 00010000 "spi-splash" mtd16: 00100000 00010000 "spi-free" root@desk-mx6ul-axelulite:~#
|
Please note that MTD partition index may change depending of flash device availability, flash device size, u-boot environment variables or kernel device driver load order. Always take care of looking inside |
- Format and initialize nand-ubi partition, which in our case is
mtd8, using UBI with:
ubiformat /dev/mtd8 ubiattach -m 8 ubimkvol /dev/ubi0 -N rootfs -m
E.g.
root@desk-mx6ul-axelulite:~# ubiformat /dev/mtd8 ubiformat: mtd8 (nand), size 109051904 bytes (104.0 MiB), 832 eraseblocks of 131072 bytes (128.0 KiB), min. I/O size 2048 bytes libscan: scanning eraseblock 831 -- 100 % complete ubiformat: 832 eraseblocks have valid erase counter, mean value is 39 ubiformat: formatting eraseblock 831 -- 100 % complete root@desk-mx6ul-axelulite:~# ubiattach -m 8 UBI device number 0, total 832 LEBs (105644032 bytes, 100.7 MiB), available 808 LEBs (102596608 bytes, 97.8 MiB), LEB size 126976 bytes (124.0 KiB) root@desk-mx6ul-axelulite:~# ubimkvol /dev/ubi0 -N rootfs -m Set volume size to 102596608 Volume ID 0, size 808 LEBs (102596608 bytes, 97.8 MiB), LEB size 126976 bytes (124.0 KiB), dynamic, name "rootfs", alignment 1
- Now mount the UBI volume using UBIFS in a temporary directory
mkdir -p /mnt/nand mount -t ubifs ubi0_0 /mnt/nand
E.g.:
root@desk-mx6ul-axelulite:~# mkdir -p /mnt/nand root@desk-mx6ul-axelulite:~# mount -t ubifs ubi0_0 /mnt/nand/ root@desk-mx6ul-axelulite:~# dmesg | tail -n 7 [ 86.268589] UBIFS (ubi0:0): Mounting in unauthenticated mode [ 86.272276] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" started, PID 276 [ 86.302293] UBIFS (ubi0:0): UBIFS: mounted UBI device 0, volume 0, name "rootfs" [ 86.302349] UBIFS (ubi0:0): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes [ 86.302377] UBIFS (ubi0:0): FS size: 101199872 bytes (96 MiB, 797 LEBs), max 808 LEBs, journal size 5079040 bytes (4 MiB, 40 LEBs) [ 86.302411] UBIFS (ubi0:0): reserved for root: 4779919 bytes (4667 KiB) [ 86.302431] UBIFS (ubi0:0): media format: w5/r0 (latest is w5/r0), UUID 36C676F6-9160-4334-B687-9CEE57A30FEF, small LPT model
- you can now extract the root file system into that directory
tar xvjf dave-image-minimal-desk-mx6ul-axelulite-fsl-imx-fb.tar.bz2 -C /mnt/nand/
- finally, you need to cleanly umount and detach the MTD partition
umount /mnt/nand/ ubidetach -m 8
E.g.
root@desk-mx6ul-axelulite:~# umount /mnt/nand/ root@desk-mx6ul-axelulite:~# ubidetach -m 8 root@desk-mx6ul-axelulite:~# dmesg | tail -n 4 [ 105.493236] UBIFS (ubi0:0): un-mount UBI device 0 [ 105.493401] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" stops [ 109.963440] ubi0: detaching mtd8 [ 109.971275] ubi0: mtd8 is detached
You can now safely reboot or turn off the system.
In U-Boot environment check the following variable, which must contain the same MTD partition number used above
nandargs=setenv bootargs ubi.mtd=8 root=ubi0_0 rootfstype=ubifs rw
