dave_user
226
edits
Changes
Created page with "<section begin=History/> {| style="border-collapse:collapse; " !colspan="4" style="width:100%; text-align:left"; border-bottom:solid 2px #ededed"|History |- ! style="border-l..."
<section begin=History/>
{| style="border-collapse:collapse; "
!colspan="4" style="width:100%; text-align:left"; border-bottom:solid 2px #ededed"|History
|-
! style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#ededed; padding:5px; color:#000000" |2024/01/30
! style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#ededed; padding:5px; color:#000000" |DESK-MX9-L-5.0.0 release
|}
<section end=History/>
__FORCETOC__
<section begin=Body/>
== MAC Address programming ==
Every network adapter has a Media Access Control address (usually shortened to MAC address). A MAC address is a six-byte identifying number permanently embedded in the firmware of the adapter, and is readable by the network and the operating system of the device on which the adapter is installed.
The address must follow the standards set by the [https://standards.ieee.org/products-services/regauth/index.html Institute of Electrical and Electronics Engineers (IEEE)], which sets computer networking standards.
The MAC address is a six-pair set of hexadecimal numbers, for example <code>a1-c2-e3-44-5f-6d</code>. Specifically, in Ethernet, the MAC address is known as the Ethernet Address, which is the unique ID serial number of the Ethernet device in one's computer. MAC Addresses are used in a Local Area Network (LAN) by computers to communicate with each other. Every adapter has a unique MAC address.
=== Platform supported===
In this Application Note, we will describe how to use the i.MX8M eFuse for programming and using the MAC address(es) and it applies to the following DAVE <code>i.MX8M family</code> products:
* [[AURA SOM | AURA SOM]]
{{ImportantMessage|text=This Application Note has been validated in the [[AURA SOM | AURA SOM]]. The commands used have been not validated in the other platform yet.}}
=== Obtaining a MAC address ===
To obtain a MAC address for your organization, please refer to our [[Deploying_Embedded_Linux_Systems#Setting_the_MAC_address_of_network_interfaces | Setting the MAC address]] wiki page with the overall information about this topic.
=== Permanent storage areas ===
Some SOCs provide programmable OTPs for security, MAC address, boot modes, etc. Usually, some of these are general-purpose registers and can be managed by the user.
In other cases, an external permanent storage device can be used for storing permanent settings like the MAC address: for the i.MX9 product family, DAVE proposes to use the ''General Purposes eFuses'' (OTP blocks) on SoC itself for storing permanently the MAC address(es).
=== MAC address programming on i.MX9 family ===
==== MAC address configuration in u-boot====
If the MAC address is not already programmed in the OTPs and the <code>ethaddr</code> u-boot variable is not set, u-boot assignes a random value (different at every power on cycle):
Net:
Warning: ethernet@428a0000 (eth1) using random MAC address - 56:ea:aa:42:d2:0e
eth1: ethernet@428a0000 [PRIME]
If the <code>ethaddr</code> is set and saved in the u-boot environment, its value is used as the MAC Address:
u-boot=> setenv ethaddr 00:50:c2:1e:af:a8
u-boot=> saveenv
Saving Environment to MMC... Writing to MMC(1)... OK
u-boot=>
==== eFuse bank registers ====
i.MX9 family uses the Bank39 Word3, Word4, and Word5 (if the SoC has two ethernet interfaces) for storing the MAC addresses. The MAC values should be properly divided into the three registers for correct programming.
{{ImportantMessage|text='''Warning!!''' eFuse programming is a permanent and non reversible action. Pay attention to the values and commands used during MAC programming.}}
==== eth0 eFuse programming ====
U-Boot uses the <code>fuse prog</code> command for writing the MAC address into the eFuse. The MAC address should be divided in high 16 bit and low 32 bits, for example MAC address <code>AB:CD:12:34:56:78</code> for eth0 is then divided into :
<pre>
fuse prog -y 39 3 0x12345678
fuse prog -y 39 4 0xABCD
</pre>
In the following example the MAC address <code>00:50:c2:1e:af:a8</code> is stored in the SOC:
* (in case of presence) clear the <code>ethaddr</code> u-boot variable
<pre class="workstation-terminal">
u-boot=> setenv ethaddr
u-boot=> saveenv
Saving Environment to MMC... Writing to MMC(1)... OK
</pre>
* program the MAC address in the OPTs with the following commands:
<pre class="workstation-terminal">
u-boot=> fuse prog 39 3 c21eafa8
Programming bank 9 word 0x00000000 to 0xc21eafa8...
Warning: Programming fuses is an irreversible operation!
This may brick your system.
Use this command only if you are sure of what you are doing!
Really perform this fuse programming? <y/N>
y
u-boot=> fuse prog 39 4 0050
Programming bank 9 word 0x00000001 to 0x00000050...
Warning: Programming fuses is an irreversible operation!
This may brick your system.
Use this command only if you are sure of what you are doing!
Really perform this fuse programming? <y/N>
y
u-boot=>
</pre>
If you want to write the eFuse value '''directly''' without confirmation, uses the <code>-y</code> parameter with the <code>fuse prog</code> command, as per the previous example:
<pre>
u-boot=> fuse prog -y 39 3 c21eafa8
u-boot=> fuse prog -y 39 4 0050
</pre>
At the next boot, the <code>ethaddr</code> value wil be read from the OPTs:
<pre class="workstation-terminal">
Warning: ethernet@30be0000 using MAC address from ROM
eth0: ethernet@30be0000
Fastboot: Normal
Normal Boot
Hit any key to stop autoboot: 0
u-boot=> print ethaddr
ethaddr=00:50:c2:1e:af:a8
u-boot=>
</pre>
The warning message informs that the <code>ethaddr</code> is not present in the u-boot environment and it has been set using the value read from the OTPs. For clearing the warning, it is enough to save the environment with <code>saveenv</code>.
<pre>
u-boot=> saveenv
</pre>
==== eFuse locking ====
The OTP eFuse registers should be locked in order to avoid unwanted registers (and then MAC addresses) modifications. OTP lock grants the MAC values cannot be modified anymore.
{{ImportantMessage|text=If not locked yet, OTP bits can be set to ''''1'''' but not reversed to ''''0'''' value, so some modifications can be applied if the eFuse registers are not locked.
TBD
==== eFuse reading ====
The eFuse registers can be read - after programming - for checking the written values:
<pre class="workstation-terminal">
u-boot=> fuse read 39 3
Reading bank 39:
Word 0x00000003: c21eafa8
u-boot=> fuse read 39 4
Reading bank 39:
Word 0x00000004: 00000050
u-boot=> fuse read 39 5
Reading bank 39:
Word 0x00000005: 0050c21e
u-boot=>
</pre>
=== Linux kernel MAC address ===
The MAC Address configured in u-boot is passed to the kernel which configures the <code>eth0</code> and <code>eth1</code> peripherals with the correct values:
<pre class="workstation-terminal">
root@desk-mx93:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:50:c2:1e:af:a8
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:82 errors:0 dropped:0 overruns:0 frame:0
TX packets:82 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:6220 (6.0 KiB) TX bytes:6220 (6.0 KiB)
root@desk-mx93:~#
</pre>
{| style="border-collapse:collapse; "
!colspan="4" style="width:100%; text-align:left"; border-bottom:solid 2px #ededed"|History
|-
! style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#ededed; padding:5px; color:#000000" |2024/01/30
! style="border-left:solid 2px #73B2C7; border-right:solid 2px #73B2C7;border-top:solid 2px #73B2C7; border-bottom:solid 2px #73B2C7; background-color:#ededed; padding:5px; color:#000000" |DESK-MX9-L-5.0.0 release
|}
<section end=History/>
__FORCETOC__
<section begin=Body/>
== MAC Address programming ==
Every network adapter has a Media Access Control address (usually shortened to MAC address). A MAC address is a six-byte identifying number permanently embedded in the firmware of the adapter, and is readable by the network and the operating system of the device on which the adapter is installed.
The address must follow the standards set by the [https://standards.ieee.org/products-services/regauth/index.html Institute of Electrical and Electronics Engineers (IEEE)], which sets computer networking standards.
The MAC address is a six-pair set of hexadecimal numbers, for example <code>a1-c2-e3-44-5f-6d</code>. Specifically, in Ethernet, the MAC address is known as the Ethernet Address, which is the unique ID serial number of the Ethernet device in one's computer. MAC Addresses are used in a Local Area Network (LAN) by computers to communicate with each other. Every adapter has a unique MAC address.
=== Platform supported===
In this Application Note, we will describe how to use the i.MX8M eFuse for programming and using the MAC address(es) and it applies to the following DAVE <code>i.MX8M family</code> products:
* [[AURA SOM | AURA SOM]]
{{ImportantMessage|text=This Application Note has been validated in the [[AURA SOM | AURA SOM]]. The commands used have been not validated in the other platform yet.}}
=== Obtaining a MAC address ===
To obtain a MAC address for your organization, please refer to our [[Deploying_Embedded_Linux_Systems#Setting_the_MAC_address_of_network_interfaces | Setting the MAC address]] wiki page with the overall information about this topic.
=== Permanent storage areas ===
Some SOCs provide programmable OTPs for security, MAC address, boot modes, etc. Usually, some of these are general-purpose registers and can be managed by the user.
In other cases, an external permanent storage device can be used for storing permanent settings like the MAC address: for the i.MX9 product family, DAVE proposes to use the ''General Purposes eFuses'' (OTP blocks) on SoC itself for storing permanently the MAC address(es).
=== MAC address programming on i.MX9 family ===
==== MAC address configuration in u-boot====
If the MAC address is not already programmed in the OTPs and the <code>ethaddr</code> u-boot variable is not set, u-boot assignes a random value (different at every power on cycle):
Net:
Warning: ethernet@428a0000 (eth1) using random MAC address - 56:ea:aa:42:d2:0e
eth1: ethernet@428a0000 [PRIME]
If the <code>ethaddr</code> is set and saved in the u-boot environment, its value is used as the MAC Address:
u-boot=> setenv ethaddr 00:50:c2:1e:af:a8
u-boot=> saveenv
Saving Environment to MMC... Writing to MMC(1)... OK
u-boot=>
==== eFuse bank registers ====
i.MX9 family uses the Bank39 Word3, Word4, and Word5 (if the SoC has two ethernet interfaces) for storing the MAC addresses. The MAC values should be properly divided into the three registers for correct programming.
{{ImportantMessage|text='''Warning!!''' eFuse programming is a permanent and non reversible action. Pay attention to the values and commands used during MAC programming.}}
==== eth0 eFuse programming ====
U-Boot uses the <code>fuse prog</code> command for writing the MAC address into the eFuse. The MAC address should be divided in high 16 bit and low 32 bits, for example MAC address <code>AB:CD:12:34:56:78</code> for eth0 is then divided into :
<pre>
fuse prog -y 39 3 0x12345678
fuse prog -y 39 4 0xABCD
</pre>
In the following example the MAC address <code>00:50:c2:1e:af:a8</code> is stored in the SOC:
* (in case of presence) clear the <code>ethaddr</code> u-boot variable
<pre class="workstation-terminal">
u-boot=> setenv ethaddr
u-boot=> saveenv
Saving Environment to MMC... Writing to MMC(1)... OK
</pre>
* program the MAC address in the OPTs with the following commands:
<pre class="workstation-terminal">
u-boot=> fuse prog 39 3 c21eafa8
Programming bank 9 word 0x00000000 to 0xc21eafa8...
Warning: Programming fuses is an irreversible operation!
This may brick your system.
Use this command only if you are sure of what you are doing!
Really perform this fuse programming? <y/N>
y
u-boot=> fuse prog 39 4 0050
Programming bank 9 word 0x00000001 to 0x00000050...
Warning: Programming fuses is an irreversible operation!
This may brick your system.
Use this command only if you are sure of what you are doing!
Really perform this fuse programming? <y/N>
y
u-boot=>
</pre>
If you want to write the eFuse value '''directly''' without confirmation, uses the <code>-y</code> parameter with the <code>fuse prog</code> command, as per the previous example:
<pre>
u-boot=> fuse prog -y 39 3 c21eafa8
u-boot=> fuse prog -y 39 4 0050
</pre>
At the next boot, the <code>ethaddr</code> value wil be read from the OPTs:
<pre class="workstation-terminal">
Warning: ethernet@30be0000 using MAC address from ROM
eth0: ethernet@30be0000
Fastboot: Normal
Normal Boot
Hit any key to stop autoboot: 0
u-boot=> print ethaddr
ethaddr=00:50:c2:1e:af:a8
u-boot=>
</pre>
The warning message informs that the <code>ethaddr</code> is not present in the u-boot environment and it has been set using the value read from the OTPs. For clearing the warning, it is enough to save the environment with <code>saveenv</code>.
<pre>
u-boot=> saveenv
</pre>
==== eFuse locking ====
The OTP eFuse registers should be locked in order to avoid unwanted registers (and then MAC addresses) modifications. OTP lock grants the MAC values cannot be modified anymore.
{{ImportantMessage|text=If not locked yet, OTP bits can be set to ''''1'''' but not reversed to ''''0'''' value, so some modifications can be applied if the eFuse registers are not locked.
TBD
==== eFuse reading ====
The eFuse registers can be read - after programming - for checking the written values:
<pre class="workstation-terminal">
u-boot=> fuse read 39 3
Reading bank 39:
Word 0x00000003: c21eafa8
u-boot=> fuse read 39 4
Reading bank 39:
Word 0x00000004: 00000050
u-boot=> fuse read 39 5
Reading bank 39:
Word 0x00000005: 0050c21e
u-boot=>
</pre>
=== Linux kernel MAC address ===
The MAC Address configured in u-boot is passed to the kernel which configures the <code>eth0</code> and <code>eth1</code> peripherals with the correct values:
<pre class="workstation-terminal">
root@desk-mx93:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:50:c2:1e:af:a8
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:82 errors:0 dropped:0 overruns:0 frame:0
TX packets:82 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:6220 (6.0 KiB) TX bytes:6220 (6.0 KiB)
root@desk-mx93:~#
</pre>
