DM365 DVEVM Ethernet MAC address - how is this obtained?

NickAllen

Dear all,

How is the DVEVM boards MAC address set in the DM365 DVEVM? Is it simply a uBoot environment setting? Is it pulled from hardware during the uBoot bootup sequence? The only approach I have in mind at the moment is querying a MAC EEPROM (SPI or I2C - both are available) to ensure our MAC's are unique but I am not too sure whether this is the best way forward.

I would really would appreciate someone giving me a a nudge in the right direction as to the most practical solution (even if it does not involve an external MAC eeprom) & some pointers.

Many thanks,
NickA

over 16 years ago

0 Miguel A. Alanis over 16 years ago

TI__Genius 9490 points

NickA,

This is more of a question for the EVM manufacturer, please send them an email at support@spectrumdigital.com.

regards,

miguel

0 Jeff Hayes over 16 years ago in reply to Miguel A. Alanis

TI__Expert 6850 points

The answer can be found in the Technical Reference Manual for the board on Spectrum Digital's website here:

http://support.spectrumdigital.com/boards/evmdm365/revf/files/EVMDM365_TechRef_revf.pdf

Please see Section 2.7. If you have further questions on the board itself, please use the Support email address above for Spectrum Digital. Thanks.

0 John Anderson over 16 years ago

Genius 5240 points

This question is probably best addressed in the Linux forum as I believe the MAC address is read by Linux from the I2C serial EEPROM. The DM365 EVM is configured for an AT24C256 EEPROM. It's actually this thread that prompted me to look into this. Our board uses an AT24C16 EEPROM. I've created a new Linux configuration for our design since it deviates from the EVM by a few parts.

At this time I'm not sure where the MAC address is located in the EEPROM. The u-boot environment variable doesn't seem to get passed to Linux. I believe that when I discover the exact location, the procedure to set the address will best be done by using U-Boot's I2C write command to store the address in the EEPROM. The Linux kernel will then pick it up by reading the EEPROM. I will pass on any more info when I have it.

John Anderson

0 John Anderson over 16 years ago

Genius 5240 points

Got some good luck searching the forum. The answer can be found in this thread....

http://e2e.ti.com/support/embedded/f/354/p/60727/217673.aspx#217673

senchuss said:

show mac addr from i2c-eeprom (via u-boot)

DM365 EVM :> imd 0x50 0x7f00.2 0x10

i2c chip addr: 0x50

addr of mac in memory: 0x7f00

You must specify suffix ".2" (dot two) after mem addr, because adr is 16bit long

last param is "how many bytes to show"

You can rewrite mac in i2c-eeprom using u-boot (cmd 'imw').

For more info, see u-boot sources.. in file /git/common/cmd_i2c.c

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DM365 DVEVM Ethernet MAC address - how is this obtained?