COM iMX6ULL Bootloader U-Boot

FAQ

Q: U-Boot doesn't start anymore?

A: See U-Boot recovery for i.MX6_Q/D/DL/S/ULL via JTAG

Q: Initialization of MAC address in the bootloader?

A: At the first start, the bootloader reads the MAC addresses from the EEPROMs and create env variables ethaddr and eth1addr. The env variables ethaddr and eth1addr could be changed during lifetime to any other MAC addresses. If you like to get back the original MAC addresses, please remove ethaddr and/or eth1addr, save environment and restart the system. In addition to that the env variables ethaddr and/or eth1addr would be initialized again with eeprom MAC addresses.

Q: The automatic update is not executed before the operating system boots!

A: Check if the command update auto is included in the bootloader environment variable bootcmd or in a script-variable which is called within bootcmd before bootm.

Q: The automatic update does not work with my desired update-media!

A: The command update auto can be configured with flags within the DHCOM settings.bin block. It is possible to disable a interface for the update mechanism. You can run a update from a disabled interface if you use the command update without the argument auto.

Downloads

Please have a look at the i.MX6ULL Download binaries/images section.

Enter Bootloader Console

Connect DHCOM UART1 via null modem cable to the RS232 Port of your PC
Start terminal program (e.g. Tera Term) on the Host PC with the following settings:
Baud rate: 115200

Data: 8 bit

Parity: none

Stop bits: 1 bit

Flow control: none
Press "DEL" on the Host PC during Core Module system start to enter bootloader console

U-Boot recovery

See U-Boot recovery for i.MX6_Q/D/DL/S/ULL via JTAG

U-boot console commands

SPI Flash

SPI Flash Init

`sf probe`

Example: sf probe

Description: Initializes the OnBoard SPI Flash

SPI Flash Read

`sf read <SDRAM address> <SPI Flash address> <Bytes>`

Example: sf read 10000000 0 100

Description: Copies 256Bytes from SPI Flash address 0x0 to SDRAM address 0x1000_0000

SPI Flash Write

`sf write <SDRAM address> <SPI Flash address> <Bytes>`

Example: sf write 10000000 40000 10000

Description: Copies 64kByte from SDRAM address 0x1000_0000 to SPI Flash address 0x4_0000

SPI Flash Erase

`sf erase <SPI Flash address> <Bytes>`

Example: sf erase 100000 1000

Description: Deletes SPI Flash content from address 0x10_0000 to 0x10_0FFF

Note: The Bytes information needs to be sector size aligned!

NAND-Flash

Read from NAND-Flash Device

`nand read <SDRAM address> <NAND Flash address> <Bytes>`

Example: nand read 80000000 400000 b40000

Description: Copies 11,25MByte from NAND Flash address 0x40_0000 to SDRAM address 0x8000_0000

Erase NAND-Flash blocks

`nand erase <Block base address> <Bytes>`

Example: nand erase 400000 40000

Description: Deletes NAND Flash content from address 0x40_0000 to 0x43_FFFF

Note: The Bytes information needs to be block size aligned!

Write to NAND-Flash Device

`nand write <SDRAM address> <NAND-Flash address> <Bytes>`

Example: nand write 80000000 400000 b40000

Description: Copies 11,25MByte from SDRAM address 0x8000_0000 to NAND Flash address 0x40_0000

Note: The Bytes information needs to be page size aligned!

Show bad NAND-Flash blocks

`nand bad`

Description: Shows the bad NAND-Flash blocks.

Show NAND-Flash content

`nand dump <NAND-Flash address>`

Example: nand dump 400000

Description: Shows the content of the specified NAND-Flash block

UBI Filesystem

Partition Definition

`mtdparts`

Example: mtdparts

Description: Shows the current nand flash partitions. In case of i.MX6 one default partition set, which includes the entire flash. For linux that partition is used to create two volumes "boot" and "rootfs".

Note: In case of UBIFS it is better to have one big partition with different volumes instead of many small partitions, because the wear leveling process is always applied to every partition.

device nand0 <gpmi-nand>, # parts = 1
 #: name                size            offset          mask_flags
 0: main-nand           0x10000000      0x00000000      0
active partition: nand0,0 - (main-nand) 0x10000000 @ 0x00000000

Set or show active partition

`ubi part <partition name>`

Example: ubi part main-nand

Description: Show or set current partition. In i.MX6ULL default case this is shold always set to main-nand.

Show ubi layout information

`ubi info layout`

Example: ubi info layout

Description: Display ubi layout information.

Mount UBI volume

`ubifsmount <UBI device>:<volume name>`

Example: ubifsmount ubi0:boot

Description: Mount UBIFS volume. The default name of the first i.MX6ULL volume is "boot".

List files

`ubifsls <directory>`

Example 1: ubifsls

Description: List files in a UBIFS directory.

Load Files from UBI volume

`ubifsload <SDRAM address> <directory+filename>`

Example 1: ubifsload 10100000 zimage

Description: Load file from an UBIFS filesystem to memory.

Unmount UBI volume

`ubifsumount`

Example: ubifsumount

Description: Unmount current volume.

SD/MMC Card

Switch between MicroSD, SD Slot and eMMC

`mmc dev <Slot number> <Partition number>`

Example: mmc dev 1

Description: Switch between SD/MMC Slots: 1 => MicroSD Slot | 2 => eMMC (0 => SD/MMC Slot is not available on i.MX6ULL)

Note eMMC hardware partition number: 0 => User partition | 1 => first boot partition | 2 => second boot partition

Initialize SD/MMC Card

`mmc rescan`

Description: Initialize new inserted SD Card

Show SD/MMC information

`mmcinfo`

Description: Shows SD/MMC device information

Device: FSL_SDHC
Manufacturer ID: 45
OEM: 100
Name: SEM08
Tran Speed: 52000000
Rd Block Len: 512
MMC version 4.41
High Capacity: Yes
Capacity: 7.3 GiB
Bus Width: 8-bit

Write to MicroSD, SD Slot and eMMC

`mmc write <SDRAM address> <block number> <block count>`

Example: mmc write 11000000 5000 400

Description: Write 512kByte (device block size is 512Byte) to the eMMC offset 10MByte.

Read from MicroSD, SD Slot and eMMC

`mmc read <SDRAM address> <block number> <block count>`

Example: mmc read 11000000 5000 400

Description: Read 512kByte (device block size is 512Byte) from the eMMC offset 10MByte.

Filesystem

NOTE: File system types are recognized automatically

List files

`ls <interface> <device[:partition]> <directory>`

Example 1: ls mmc 1

Example 2: ls mmc 1 /folder

Load Files from device to SDRAM

`load <interface> <device[:partition]> <SDRAM address> <directory+filename>`

Example 1: load mmc 1 10100000 nk.gz

Example 2: load mmc 1 10100000 /folder/nk.gz

Ethernet

Load File via TFTP to SDRAM

`tftp <SDRAM address> <directory+filename>`

Example: tftp 80100000 nk.gz

Example TFTP Server: "Winagents TFTP Server Manager"

Note: For TFTP download it is necessary to config the ENV variables "ipaddr" and "serverip"

Load File via TFTP to SDRAM using DHCP

`dhcp <SDRAM address> <directory+filename>`

Example: dhcp 80100000 nk.gz

Example TFTP Server: "Winagents TFTP Server Manager"

Note: It is necessary to config the ENV variable "serverip" with the ip-address of your TFTP-Server

Ping

`ping <IP address>`

Example: ping 192.168.55.32

Unzip

`unzip <source address> <destination address>`

Example: unzip 12900000 10100000

Note: The unzip command is supporting the gzip file format.

Bitmap

Information

`bmp info <Bitmap address>`

Image size    : 800 x 480
Bits per pixel: 8
Compression   : 0

Display

`bmp display <Bitmap SDRAM address> [x y]`

Note: It is necessary to load bitmap file to memory address with an offset of an odd multiple of +2, since the use of a four-byte alignment will cause alignment exceptions at run-time.

Memory

Display

`md[.b, .w, .l] <address> [count]`

Example: md.b 80100000 100

Write

`mw[.b, .w, .l] <address> <value> [count]`

Example: mw.b 80100000 aa 100

Description: Writes the value 0xaa to the next 0x100 bytes from the address 0x8010_0000.

Copy

`cp[.b, .w, .l] <source> <destination> <count>`

I2C

Set current I2C bus

`i2c dev <I2C bus>`

Example: i2c dev 0

Description: Set current I2C bus to 0.

Valid buses on i.MX6ULL:
0 = DHCOM I2C port 1
1 = DHCOM I2C port 2

List available devices

`i2c probe`

Description: Test for and show device(s) on the I2C bus.

Valid chip addresses: 32 50 51 52 53 58 59

Read

`i2c md <I2C address> <start address> <end address>`

Example: i2c md 57 10 20

Description: Reads 16 Bytes from the address 0x10 to address 0x20.

Write

`i2c mw <I2C address> <I2C register> <Value> <Bytes>`

Example: i2c mw 57 0 aa 5

Description: Writes 0xaa to 5 Bytes from the offset 0.

Environment

Show ENV variables

`env print`

or

`printenv`

bootdelay=0
baudrate=38400
ipaddr=192.168.55.230
serverip=192.168.55.36
gatewayip=192.168.55.36
netmask=255.255.255.0
frias=5
...
Environment size: 449/262140 bytes

Set ENV variables

`env set <ENV name> <ENV value>`

or

`setenv <ENV name> <ENV value>`

Example: env set ipaddr 192.168.55.2

Note: If you need to edit "bootcmd" it is necessary to insert ; between the unique commands. Put the whole sequence in quotation marks '...'.

Save ENV variables

`env save`

or

`saveenv`

Delete ENV variable

`env delete <ENV name>`

Revert to default ENV (all)

`env default -a`

Revert to default ENV (almost everything: preserve DH serial numbers and ethernet MAC addresses)

`env default -ae`

Import ENV from textfile

`env import -t <SDRAM address> $filesize`

Example:

load mmc 0 0x10000000 uLinuxEnv.txt

env import -t 0x10000000 $filesize

Important:

The uLinuxEnv.txt file should have unix line ending. Also make sure that there is an empty line at the end of the file.

USB Mass Storage

Use device as USB Mass Storage

`ums <USB_controller> <devtype> <dev[:part]>`

Example: Write an image on PDK2 to the eMMC using the "ums" command:

1. Connect the USB OTG on the PDK2 with a suitable cable to a computer running Debian Linux

2. Go to the U-Boot console on the module

3. Start UMS by typing:

`ums 0 mmc 2`

4. Eject partitions that may appear

5. Double klick on the image (*.img.xz file)

6. Select a destination drive

7. Press "Start Restoring..."

8. Stop UMS in U-Boot by pressing CTRL+C

How to do Updates

DHCOM Update Mechanism

Building U-Boot

Prepare Build Environment

Download and start the Virtual Machine based on Debian 8 (see i.MX6 Downloads)
Install Denx ELDK 5.4 to /opt (Available at ftp://ftp.denx.de/pub/eldk/5.4/iso/: we use eldk-5.4-armv7a.iso)

Get Sources

1. Start a terminal on Linux 2. `# git clone https://github.com/dh-electronics/u-boot-imx6qdl.git` 3. `# cd u-boot-imx6qdl` 4. `# git checkout release/v1.0.0.6 # checkout latest/required branch or tag`

Start Build

6. `# ./uboot_make [q_d dl s s_1g]` # add argument 'dl' to build for Duallite (if unsure contact DH electronics)

Your new u-boot.imx file is available in u-boot-imx6qdl/
If your build does fail please check content of uboot_make and adjust PATH.

Attention: Risk of bricking the Device!!