DESK-MX6UL-L/Deployment/Standalone boot

History
Version	Issue Date	Notes
1.0.1	Jun 2021	First DESK release

Standalone boot

Introduction

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. A complete deployment strategy has to be carefully identifiyed taking into account the overall arguments like: boot speed, safe boot, recovery mechanisms, watchdog supervisor, etc.

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 threee 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
• booting with NAND only
  • in this configuration the whole system will boot without the need of a NOR flash storage, all images and the root file system will be fetched from NAND flash
• booting with eMMC only
  • in this configuration the whole system will boot without the need of a NOR/NAND flashes storage, all images and the root file system will be fetched from eMMC flash

Program boot images into NOR flash

u-Boot

Update to the latest u-boot version allows usage of u-boot environment variables available.

=> run load
Using FEC0 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.89
Filename 'desk-mx-l/desk-mx6ul-l-1.0.1_mx6uldesk_lynx_spi_SPL'.
Load address: 0x80800000
Loading: ############
         543.9 KiB/s
done
Bytes transferred = 56320 (dc00 hex)
=> 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 0xdc00
SF: 56320 bytes @ 0x400 Written: OK
=> run load_uboot
Using FEC0 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.89
Filename 'desk-mx-l/desk-mx6ul-l-1.0.1_mx6uldesk_lynx_spi_u-boot.img'.
Load address: 0x80800000
Loading: #################################################################
         ####################################
         584 KiB/s
done
Bytes transferred = 512568 (7d238 hex)
=> run spi_update_uboot
SF: Detected is25lp128 with page size 256 Bytes, erase size 64 KiB, total 16 MiB
SF: 524288 bytes @ 0x10000 Erased: OK
device 0 offset 0x10000, size 0x7d238
SF: 512568 bytes @ 0x10000 Written: OK
=>

kernel image and device tree

We assume that the following environment variables are present in u-boot:

loadk=tftpboot ${loadaddr} ${serverip}:${bootfile}
loadfdt=tftpboot ${fdtaddr} ${serverip}:${fdtfile}
spi_updatek=sf erase 200000 800000; sf write ${loadaddr} 200000 ${filesize}
spi_updatefdt=sf erase 180000 80000; sf write ${fdtaddr} 180000 ${filesize}
spi_loadk=sf read ${loadaddr} 200000 800000
spi_loadfdt=sf read ${fdtaddr} 180000 80000
spi_nand=sf probe; run spi_loadk spi_loadfdt nandargs addcons addmisc; if run configid_fixupfdt; then bootm ${loadaddr} - ${fdtaddr}; fi

• Update the bootfile and fdtfile environment 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.:

=> sf probe; run loadk spi_updatek loadfdt spi_updatefdt
SF: Detected is25lp128 with page size 256 Bytes, erase size 64 KiB, total 16 MiB
Using FEC0 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.89
Filename 'desk-mx-l/desk-mx6ul-l-1.0.1_uImage'.
Load address: 0x80800000
Loading: #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         ##############
         553.7 KiB/s
done
Bytes transferred = 7056696 (6bad38 hex)
SF: 8388608 bytes @ 0x200000 Erased: OK
device 0 offset 0x200000, size 0x6bad38
SF: 7056696 bytes @ 0x200000 Written: OK
Using FEC0 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.89
Filename 'desk-mx-l/desk-mx6ul-l-1.0.1_imx6ul-axelulite-cb003a.dtb'.
Load address: 0x83000000
Loading: #######
         584 KiB/s
done
Bytes transferred = 34095 (852f hex)
SF: 524288 bytes @ 0x180000 Erased: OK
device 0 offset 0x180000, size 0x852f
SF: 34095 bytes @ 0x180000 Written: OK
=>

Reboot the system and configure U-Boot to apply the new configuration

=> setenv bootcmd run spi_nand
=> saveenv

Program boot images into NAND flash

u-Boot

u-boot on NAND flash must be programmed using NXP kobs-ng utility: this tool is required for writing the correct u-boot image on NAND storing all information needed by bootrom to identify the NAND as a boot device.

Here below an example:

• boot the system via SD on NFS
• uses a rfs with kobs-ng utility available on it (e.g. DAVE's rfs provided with <KIT>)
• copy the related u-boot imx image file on nfs /home/root (for example)
• execute kobs-ng passing the parameters for flashing u-boot on NAND

root@desk-mx6ul-axelulite:~# kobs-ng -x -v -w desk-mx6ul-l-1.0.2_mx6uldesk_axelulite_nand_SPL
MTD CONFIG:
  chip_0_device_path = "/dev/mtd0"
  chip_1_device_path = "(null)"
  search_exponent = 2
  data_setup_time = 80
  data_hold_time = 60
  address_setup_time = 25
  data_sample_time = 6
  row_address_size = 3
  column_address_size = 2
  read_command_code1 = 0
  read_command_code2 = 48
  boot_stream_major_version = 1
  boot_stream_minor_version = 0
  boot_stream_sub_version = 0
  ncb_version = 3
  boot_stream_1_address = 0
  boot_stream_2_address = 0
         -- We add the 1k-padding to the uboot.
.tmp_kobs_ng: verifying using key '00000000000000000000000000000000'
.tmp_kobs_ng: is a valid bootstream for key '00000000000000000000000000000000'
mtd: use new bch layout raw access mode
mtd: opening: "/dev/mtd0"
NFC geometry :
        ECC Strength       : 2
        Page Size in Bytes : 2071
        Metadata size      : 10
        ECC Chunk Size in byte : 512
        ECC Chunk count        : 4
        Block Mark Byte Offset : 2028
        Block Mark Bit Offset  : 2
====================================================
mtd: opened '/dev/mtd0' - '(null)'
mtd: max_boot_stream_size_in_bytes = 3670016
mtd: boot_stream_size_in_bytes = 672812
mtd: boot_stream_size_in_pages = 329
mtd: #1 0x00100000 - 0x00480000 (0x001a442c)
mtd: #2 0x00480000 - 0x00800000 (0x0052442c)
FCB
  m_u32Checksum = 0x00000000
  m_u32FingerPrint = 0x20424346
  m_u32Version = 0x01000000
  m_NANDTiming.m_u8DataSetup = 80
  m_NANDTiming.m_u8DataHold = 60
  m_NANDTiming.m_u8AddressSetup = 25
  m_NANDTiming.m_u8DSAMPLE_TIME = 6
  m_u32PageDataSize = 2048
  m_u32TotalPageSize = 2112
  m_u32SectorsPerBlock = 64
  m_u32NumberOfNANDs = 0
  m_u32TotalInternalDie = 0
  m_u32CellType = 0
  m_u32EccBlockNEccType = 1
  m_u32EccBlock0Size = 512
  m_u32EccBlockNSize = 512
  m_u32EccBlock0EccType = 1
  m_u32MetadataBytes = 10
  m_u32NumEccBlocksPerPage = 3
  m_u32EccBlockNEccLevelSDK = 0
  m_u32EccBlock0SizeSDK = 0
  m_u32EccBlockNSizeSDK = 0
  m_u32EccBlock0EccLevelSDK = 0
  m_u32NumEccBlocksPerPageSDK = 0
  m_u32MetadataBytesSDK = 0
  m_u32EraseThreshold = 0
  m_u32Firmware1_startingPage = 512
  m_u32Firmware2_startingPage = 2304
  m_u32PagesInFirmware1 = 329
  m_u32PagesInFirmware2 = 329
  m_u32DBBTSearchAreaStartAddress = 256
  m_u32BadBlockMarkerByte = 2028
  m_u32BadBlockMarkerStartBit = 2
  m_u32BBMarkerPhysicalOffset = 2048
  m_u32BCHType = 0
  m_NANDTMTiming.m_u32TMTiming2_ReadLatency = 0
  m_NANDTMTiming.m_u32TMTiming2_PreambleDelay = 0
  m_NANDTMTiming.m_u32TMTiming2_CEDelay = 0
  m_NANDTMTiming.m_u32TMTiming2_PostambleDelay = 0
  m_NANDTMTiming.m_u32TMTiming2_CmdAddPause = 0
  m_NANDTMTiming.m_u32TMTiming2_DataPause = 0
  m_NANDTMTiming.m_u32TMSpeed = 0
  m_NANDTMTiming.m_u32TMTiming1_BusyTimeout = 0
  m_u32DISBBM = 0
  m_u32BBMarkerPhysicalOffsetInSpareData = 0
DBBT
  m_u32Checksum = 0x00000000
  m_u32FingerPrint = 0x54424244
  m_u32Version = 0x01000000
  m_u32DBBTNumOfPages = 0
Firmware: image #0 @ 0x100000 size 0xa4800 - available 0x380000
Firmware: image #1 @ 0x480000 size 0xa4800 - available 0x380000
-------------- Start to write the [ FCB ] -----
mtd: erasing @0:0x0-0x20000
mtd: Writing FCB0 [ @0:0x0 ] (840) *
mtd: erasing @0:0x20000-0x40000
mtd: Writing FCB1 [ @0:0x20000 ] (840) *
mtd: erasing @0:0x40000-0x60000
mtd: Writing FCB2 [ @0:0x40000 ] (840) *
mtd: erasing @0:0x60000-0x80000
mtd: Writing FCB3 [ @0:0x60000 ] (840) *
mtd_commit_bcb(FCB): status 0

-------------- Start to write the [ DBBT ] -----
mtd: erasing @0:0x80000-0xa0000
mtd: Writing DBBT0 [ @0:0x80000 ] (800) *
mtd: erasing @0:0xa0000-0xc0000
mtd: Writing DBBT1 [ @0:0xa0000 ] (800) *
mtd: erasing @0:0xc0000-0xe0000
mtd: Writing DBBT2 [ @0:0xc0000 ] (800) *
mtd: erasing @0:0xe0000-0x100000
mtd: Writing DBBT3 [ @0:0xe0000 ] (800) *
mtd_commit_bcb(DBBT): status 0

---------- Start to write the [ .tmp_kobs_ng ]----
mtd: Writting .tmp_kobs_ng: #0 @0: 0x00100000 - 0x001a4800
mtd: erasing @0:0x100000-0x120000
mtd: erasing @0:0x120000-0x140000
mtd: erasing @0:0x140000-0x160000
mtd: erasing @0:0x160000-0x180000
mtd: erasing @0:0x180000-0x1a0000
mtd: erasing @0:0x1a0000-0x1c0000
mtd: The last page is not full : 1068
mtd: We write one page for save guard. *
mtd: Writting .tmp_kobs_ng: #1 @0: 0x00480000 - 0x00524800
mtd: erasing @0:0x480000-0x4a0000
mtd: erasing @0:0x4a0000-0x4c0000
mtd: erasing @0:0x4c0000-0x4e0000
mtd: erasing @0:0x4e0000-0x500000
mtd: erasing @0:0x500000-0x520000
mtd: erasing @0:0x520000-0x540000
mtd: The last page is not full : 1068
mtd: We write one page for save guard. *
root@desk-mx6ul-axelulite:~# flash_erase /dev/mtd1 0 0
Erasing 128 Kibyte @ 5e0000 -- 100 % complete
root@desk-mx6ul-axelulite:~# nandwrite -p /dev/mtd1 desk-mx6ul-l-1.0.1_mx6uldesk_axelulite_nand_u-boot.img
Writing data to block 0 at offset 0x0
Writing data to block 1 at offset 0x20000
Writing data to block 2 at offset 0x40000
Writing data to block 3 at offset 0x60000
root@desk-mx6ul-axelulite:~#

kernel image and device tree

We assume that the following environment variables are present in u-boot:

nand_updatek=nand erase.part nand-kernel; nand write ${loadaddr} nand-kernel ${filesize}
nand_updatefdt=nand erase.part nand-fdt; nand write ${fdtaddr} nand-fdt ${filesize}
nand_loadk=nand read ${loadaddr} nand-kernel
nand_loadfdt=nand read ${fdtaddr} nand-fdt
nand_nand=run nand_loadk nand_loadfdt nandargs addcons addmisc; if run configid_fixupfdt; then bootm ${loadaddr} - ${fdtaddr}; fi

• Update the bootfile and fdtfile environment variables to fit the filename as found inside the TFTP server.
• Program kernel and device tree on NAND flash with the following U-Boot command

run loadk nand_updatek loadfdt nand_updatefdt

E.g.:

=> run loadk nand_updatek loadfdt nand_updatefdt
Using FEC0 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.89
Filename 'desk-mx-l/desk-mx6ul-l-1.0.1_uImage'.
Load address: 0x80800000
Loading: #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         ##############
         504.9 KiB/s
done
Bytes transferred = 7056696 (6bad38 hex)

NAND erase.part: device 0 offset 0xc00000, size 0x800000
Erasing at 0x13e0000 -- 100% complete.
OK

NAND write: device 0 offset 0xc00000, size 0x6bad38
 7056696 bytes written: OK
Using FEC0 device
TFTP from server 192.168.0.125; our IP address is 192.168.0.89
Filename 'desk-mx-l/desk-mx6ul-l-1.0.1_imx6ul-axelulite-cb003a.dtb'.
Load address: 0x83000000
Loading: #######
         165 KiB/s
done
Bytes transferred = 34095 (852f hex)

NAND erase.part: device 0 offset 0xa00000, size 0x100000
Erasing at 0xae0000 -- 100% complete.
OK

NAND write: device 0 offset 0xa00000, size 0x852f
 34095 bytes written: OK
=>

Reboot the system and configure U-Boot to apply the new configuration

=> setenv bootcmd run nand_nand
=> saveenv

Program root file system into NAND flash

• Boot the system via SD or NFS as described in the e [[(<KIT>)#Quick_start_guide|Quick start guide]]
• 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 00020000 "nand-SPL"
mtd1: 00600000 00020000 "nand-uboot"
mtd2: 00100000 00020000 "nand-env1"
mtd3: 00100000 00020000 "nand-env2"
mtd4: 00100000 00020000 "nand-fdt"
mtd5: 00100000 00020000 "nand-spare"
mtd6: 00800000 00020000 "nand-kernel"
mtd7: 00400000 00020000 "nand-splash"
mtd8: 06800000 00020000 "nand-ubi"
mtd9: 00010000 00001000 "spi-SPL"
mtd10: 000f0000 00001000 "spi-uboot"
mtd11: 00040000 00001000 "spi-env1"
mtd12: 00040000 00001000 "spi-env2"
mtd13: 00080000 00001000 "spi-dtb"
mtd14: 00800000 00001000 "spi-kernel"
mtd15: 00400000 00001000 "spi-splash"
mtd16: 00200000 00001000 "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 /proc/mtd to match your specific layout

• Format and initialize nand-ubi partition, which in our case is mtd7, 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
li[   52.440377] random: crng init done% complete
[   52.446177] random: 7 urandom warning(s) missed due to ratelimiting
libscan: scanning eraseblock 831 -- 100 % complete
ubiformat: 830 eraseblocks have valid erase counter, mean value is 0
ubiformat: warning!: 2 of 832 eraseblocks contain non-UBI data
ubiformat: continue? (y/N) y
ubiformat: formatting eraseblock 831 -- 100 % complete
root@desk-mx6ul-axelulite:~# ubiattach -m 8
[   68.203880] ubi0: attaching mtd8
[   69.488529] ubi0: scanning is finished
[   69.526881] ubi0: attached mtd8 (name "nand-ubi", size 104 MiB)
[   69.545319] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes
[   69.552230] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048
[   69.576138] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096
[   69.587298] ubi0: good PEBs: 832, bad PEBs: 0, corrupted PEBs: 0
[   69.594040] ubi0: user volume: 0, internal volumes: 1, max. volumes count: 128
[   69.601292] ubi0: max/mean erase counter: 2/1, WL threshold: 4096, image sequence number: 1623728395
[   69.613873] ubi0: available PEBs: 808, total reserved PEBs: 24, PEBs reserved for bad PEB handling: 20
[   69.623519] ubi0: background thread "ubi_bgt0d" started, PID 264
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
root@desk-mx6ul-axelulite:~#

• 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
[  104.646929] UBIFS (ubi0:0): default file-system created
[  104.656524] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" started, PID 271
[  104.795980] UBIFS (ubi0:0): UBIFS: mounted UBI device 0, volume 0, name "rootfs"
[  104.803631] UBIFS (ubi0:0): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[  104.817174] UBIFS (ubi0:0): FS size: 101199872 bytes (96 MiB, 797 LEBs), journal size 5079040 bytes (4 MiB, 40 LEBs)
[  104.829554] UBIFS (ubi0:0): reserved for root: 4779919 bytes (4667 KiB)
[  104.838248] UBIFS (ubi0:0): media format: w5/r0 (latest is w5/r0), UUID 0687F325-4ED1-488F-B637-57FAEADE745E, small LPT model
root@desk-mx6ul-axelulite:~#

• you can now extract the root file system into that directory

tar xvjf tar xjf desk-mx6ul-l-1.0.1_dave-image-devel-desk-mx6ul.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/
[ 1264.460672] UBIFS (ubi0:0): un-mount UBI device 0
[ 1264.465626] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" stops
root@desk-mx6ul-axelulite:~# ubidetach -m 8
[ 1270.298143] ubi0: detaching mtd8
[ 1270.316092] ubi0: mtd8 is detached
root@desk-mx6ul-axelulite:~#

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

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