On Wed, Feb 13, 2019 at 7:01 AM Bin Meng bmeng.cn@gmail.com wrote:
On Tue, Feb 12, 2019 at 6:23 PM Andreas Schwab schwab@suse.de wrote:
On Feb 12 2019, Bin Meng bmeng.cn@gmail.com wrote:
The env var is stored in whatever supported media in U-Boot. Not like PCI NICs which normally have EEPROM to store pre-flashed MAC address by their vendors, for most embedded network controllers in the SoC, normally there is no hardware provided mechanism to ensure a unique MAC address, instead it relies on software to program one to the hardware before bringing it up.
On the Hifive the MAC is part of the initial DT, so there is no need to use a secondary store.
So for the HiFive board, who is supposed to guarantee the uniqueness of the MAC address? Does SiFive program DT with different MAC to every board they shipped? If so, we can just read "local-mac-address" from DT in U-Boot.
General practice (atlease what I have seen on few boards), is that board will have unique MAC address printed/labelled for each Ethernet port. We can just set-and-save "ethaddr" U-Boot env variable based on MAC address printed on board.
Unfortunately, I was not able to find printed MAC address on Unleashed board.
Regards, Anup