Beaglebone: Peripheral boot from EMAC1


I am playing with beaglebone (rev A5) and I am trying to make it peripheral boot from the EMAC1 peripheral.

I have placed R100 on the board to pull SYS_BOOT[0] low so boot mode reads: 10110b. I have verified this from the CONTROL_STATUS register.

The rest of the hardware seems correct for MII mode peripheral boot from EMAC1. MAC_ID0 EFUSE is programmed with the MAC address.

EMAC1 boot does not happen however, I do not get an ethernet link on the switch I have connected so I figure there is still something wrong.

The AM335x errata 1.0.7 does seem to pertain to the PHY used since the datasheet for LAN8710A does not indicate it updates the speed selection bits to reflect current speed when in autonegotiate mode. I wonder if this is the reason for failure.

Has anyone succeeded in EMAC peripheral booting of the 'bone?

  • Juha

From what I have heard, peripheral boot cannot work at 100MB/s as the ROM does not read the PHY to detect the speed. You may be able to connect to a 10mB hub and get that to work. But to my knowledge I do not know if anyone has this working.


Thanks for your reply. I tried this with forced 10Mbit connection with no luck.

  • Juha