[U-Boot] [linux-sunxi] [PATCHv6 12/28] net: Add ability to set MAC address via EEPROM

[Jonathan Liu]

Hi Olliver,

On 15 May 2017 at 18:02, Olliver Schinagl <oliver at schinagl.nl> wrote:
> This patch allows Kconfig to enable and set parameters to make it
> possible to read the MAC address from an EEPROM. The net core layer then
> uses this information to read MAC addresses from this EEPROM.
>
> Besides the various tuneables as to how to access the eeprom (bus,
> address, addressing mode/length, 2 configurable that are EEPROM generic
> (e.g. SPI or some other form of access) which are:
>
> NET_ETHADDR_EEPROM_OFFSET, indicating where in the EEPROM the start of
> the MAC address is. The default is 8 allowing for 8 bytes before the MAC
> for other purposes (header MAGIC for example).

Note that Olimex has started to write their own data to the EEPROM for
their A20 boards:
https://github.com/OLIMEX/OLINUXINO/blob/master/SOFTWARE/A20/A20-eeprom-contents/Olimex-A20-EEPROM-september-2017.pdf

>
> NET_ETHADDR_EEPROM_CRC8, indicating the MAC is appended with a CRC8-CCIT
> checksum that should be verified.
>
> Currently only I2C eeproms have been tested and thus only those options
> are available, but shouldn't be a limit. NET_ETHADDR_EEPROM_SPI can be
> just as created and added.
>
> The code currently first checks if there is a non-zero MAC address in
> the eeprom. If that fails to be the case, the read_rom_hwaddr can be
> used by a board to supply the MAC in other ways.
>
> If both these fails, the other code is still in place to query the
> environent, which then can be used to override the hardware supplied
> data.
>
> Signed-off-by: Olliver Schinagl <oliver at schinagl.nl>

Regards,
Jonathan