Setting MAC address on iMX6ULL - Revision history

KrzysztofChojnowski at 09:14, 6 October 2023

2023-10-06T09:14:57Z

← Older revision		Revision as of 09:14, 6 October 2023
Line 30:		Line 30:
	* StarSBC-6ULL ''board/somlabs/starsbc-6ull/starsbc-6ull.env''		* StarSBC-6ULL ''board/somlabs/starsbc-6ull/starsbc-6ull.env''
	* StarSOM-6ULL ''board/somlabs/starsom-6ull/starsom-6ull.env''		* StarSOM-6ULL ''board/somlabs/starsom-6ull/starsom-6ull.env''
	* VisionSOM-6ULL ''board/somlabs/~~visionsom_6ull~~/~~visionsom_6ull~~.env''		* VisionSOM-6ULL ''board/somlabs/visionsom-6ull/visionsom-6ull.env''

	Older u-boot versions		Older u-boot versions

KrzysztofChojnowski at 09:14, 6 October 2023

2023-10-06T09:14:40Z

← Older revision		Revision as of 09:14, 6 October 2023
Line 28:		Line 28:
	U-boot 2022.04 or later		U-boot 2022.04 or later

	* StarSBC-6ULL ''board/somlabs/~~starsbc_6ull~~/~~starsbc_6ull~~.h''		* StarSBC-6ULL ''board/somlabs/starsbc-6ull/starsbc-6ull.env''
	* StarSOM-6ULL ''board/somlabs/~~starsom_6ull~~/~~starsom_6ull~~.h''		* StarSOM-6ULL ''board/somlabs/starsom-6ull/starsom-6ull.env''
	* VisionSOM-6ULL ''board/somlabs/visionsom_6ull/visionsom_6ull.env''		* VisionSOM-6ULL ''board/somlabs/visionsom_6ull/visionsom_6ull.env''

KrzysztofChojnowski at 09:13, 6 October 2023

2023-10-06T09:13:34Z

← Older revision		Revision as of 09:13, 6 October 2023
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	The default U-Boot configuration generates a random MAC address for the ETH interface. This behavior may be changed by adding a new env variable to the U-Boot. The environment variables are stored in one of the following files:		The default U-Boot configuration generates a random MAC address for the ETH interface. This behavior may be changed by adding a new env variable to the U-Boot. The environment variables are stored in one of the following files:

			U-boot 2022.04 or later

			* StarSBC-6ULL ''board/somlabs/starsbc_6ull/starsbc_6ull.h''
			* StarSOM-6ULL ''board/somlabs/starsom_6ull/starsom_6ull.h''
			* VisionSOM-6ULL ''board/somlabs/visionsom_6ull/visionsom_6ull.env''

			Older u-boot versions

	* StarSBC-6ULL ''include/configs/starsbc_6ull.h''		* StarSBC-6ULL ''include/configs/starsbc_6ull.h''

KrzysztofChojnowski: Created page with "{{PageHeader|Setting MAC address on iMX6ULL}} toc This article describes a couple of methods to set the board MAC address and avoid the assignment its random value after..."

2023-02-27T21:09:17Z

Created page with "{{PageHeader|Setting MAC address on iMX6ULL}} __toc__ This article describes a couple of methods to set the board MAC address and avoid the assignment its random value after..."

New page

{{PageHeader|Setting MAC address on iMX6ULL}}

__toc__

This article describes a couple of methods to set the board MAC address and avoid the assignment its random value after device reboot.

== Setting MAC address in systemd-networkd service files ==

The systemd-networkd interface configuration is stored in the *.network files within the ''/etc/systemd/network'' directory. To assign a MAC address to the chosen interface a new configuration file should be created (if it does not exist already). For the ''eth0'' interface a file named ''25-eth.network'' may be created with the following content:

<pre>
[Match]
Name=eth0

[Link]
MACAddress=fe:51:11:6c:62:e8

[Network]
DHCP=ipv4
</pre>

This file will assign the given address to the ''eth0'' interface and enable the DHCP client for IPv4 address setting. More information may be found on the systemd-networkd service documentation.

== U-Boot env variable ==

The default U-Boot configuration generates a random MAC address for the ETH interface. This behavior may be changed by adding a new env variable to the U-Boot. The environment variables are stored in one of the following files:

* StarSBC-6ULL ''include/configs/starsbc_6ull.h''
* StarSOM-6ULL ''include/configs/starsom_6ull.h''
* VisionSOM-6ULL ''include/configs/visionsom_6ull.h''

A new MAC address may be set by adding the following variable:

<pre>
ethaddr=fe:51:11:6c:62:e8
</pre>

== Linux device tree file ==

A MAC address may be defined in the dtb file used by the Linux kernel. The address definition should be added in the device tree source in the following section:

<pre>
&fec1 {
local-mac-address = [ 70 b3 d5 1a 70 06 ];
}
</pre>

This code configures given MAC address for the ''fec1'' interface.

To prevent overwriting this value by u-boot, a random address generation should be disabled in the bootloader defconfig:

* StarSBC-6ULL ''configs/starsbc_6ull_defconfig''
* StarSOM-6ULL ''configs/starsom_6ull_defconfig''
* VisionSOM-6ULL ''configs/visionsom_6ull_defconfig''

<pre>
CONFIG_NET_RANDOM_ETHADDR=n
</pre>

== Processor OTP memory ==

{| class="frame-green"
|-
|'''NOTE!''' The described operation may be performed only once and cannot be reversed!
|}

The iMX6ULL processor has an OTP memory area that is used by default to store the permanent MAC address. The registers responsible for this are described in the Reference Manual:

* OTP Bank4 Word2 (MAC Address) (OCOTP_MAC0)
* OTP Bank4 Word3 (MAC Address) (OCOTP_MAC1)
* OTP Bank4 Word4 (MAC Address) (OCOTP_MAC2)

This area may be written from the U-Boot console by executing the following commands. In this example the '''fe:51:11:6c:62:e8''' address is stored in OTP:

<pre>
fuse prog 4 2 0x116c62e8
fuse prog 4 3 0xfe51
</pre>

Setting MAC address on iMX6ULL - Revision history

KrzysztofChojnowski at 09:14, 6 October 2023

KrzysztofChojnowski at 09:14, 6 October 2023

KrzysztofChojnowski at 09:13, 6 October 2023

KrzysztofChojnowski: Created page with "{{PageHeader|Setting MAC address on iMX6ULL}} __toc__ This article describes a couple of methods to set the board MAC address and avoid the assignment its random value after..."

KrzysztofChojnowski: Created page with "{{PageHeader|Setting MAC address on iMX6ULL}} toc This article describes a couple of methods to set the board MAC address and avoid the assignment its random value after..."