[U-Boot] [U-Boot, PATCHv1, 1/3] net: Add ability to set MAC address via EEPROM to Kconfig

Joe Hershberger joe.hershberger at gmail.com
Thu Dec 10 21:26:56 CET 2015


Hi Hans,

On Thu, Dec 10, 2015 at 4:29 AM, Hans de Goede <hdegoede at redhat.com> wrote:
> Hi Olliver and Joe,
>
> On 11/30/2015 05:50 PM, Oliver Schinagl wrote:
>>
>> From: Olliver Schinagl <o.schinagl at ultimaker.com>
>>
>> This patch allows Kconfig to enable and set parameters to make it
>> possible to read the MAC address from an EEPROM. This patch only sets up
>> some environment variables, it is up to the specific boards to actually
>> use these defines.
>>
>> 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).
>>
>> 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.
>>
>> Signed-off-by: Olliver Schinagl <o.schinagl at ultimaker.com>
>
>
> Thanks, from a sunxi pov this and the other 2 patches look good.
>
> Joe can we have your ack for this one please and/or can you merge this
> one through your tree? Either way I will take care of the other 2
> patches in this set.

I'm fine either way. I'm thinking I'll be pulling anything assigned to
me in patchwork next week.

> From my pov this is fine as v2016.01 material, but if you would
> rather postpone this to v2016.04 that is fine too.

Seems safe enough. v2016.01 is fine with me.

> Thanks & Regards,
>
> Hans
>
>
>
>> ---
>>   doc/README.enetaddr | 36 +++++++++++++++++++++++++++++++++
>>   net/Kconfig         | 58
>> +++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 94 insertions(+)
>>
>> diff --git a/doc/README.enetaddr b/doc/README.enetaddr
>> index 50e4899..c53b455 100644
>> --- a/doc/README.enetaddr
>> +++ b/doc/README.enetaddr
>> @@ -47,6 +47,42 @@ Correct flow of setting up the MAC address
>> (summarized):
>>   Previous behavior had the MAC address always being programmed into
>> hardware
>>   in the device's init() function.
>>
>> +--------
>> + EEPROM
>> +--------
>> +
>> +When there is an EEPROM available on a board, but the EEPROM is not large
>> enough
>> +to store the whole environment, it may be desired to store a MAC address
>> in the
>> +onboard EEPROM. Using CONFIG_NET_ETHADDR_EEPROM enables this feature.
>> Depending
>> +on the board, the EEPROM may be connected on various methods, but
>> currently,
>> +only the I2C bus is available via CONFIG_NET_ETHADDR_EEPROM_I2C.
>> +CONFIG_NET_ETHADDR_EEPROM_I2C_BUS I2C bus on which the eeprom is present
>> and
>> +CONFIG_NET_ETHADDR_EEPROM_I2C_ADDR set the address of the EEPROM, which
>> +defaults to the very common 0x50. Small size EEPROM's generally use
>> single byte
>> +addressing but larger EEPROM's may use double byte addressing, which can
>> be
>> +configured using CONFIG_NET_ETHADDR_EEPROM_ADDRLEN.
>> +
>> +Within the EEPROM, the MAC address can be stored on any arbitrary offset,
>> +CONFIG_NET_ETHADDR_EEPROM_OFFSET sets this to 8 as a default however,
>> allowing
>> +the first 8 bytes to be used for some header magic for example.
>> +
>> +After the 6 bytes used for the MAC address, there is an 8 byte field to
>> indicate
>> +the ID of the network interface this MAC address is for. 0xff here means
>> 'for
>> +the first available interface' and 0x00 means the first network
>> interface, 0x01
>> +the second, etc. It is up to the platform however to enforce this.
>> +
>> +Appending the 6 MAC bytes and the 7th interface byte is a CRC8 byte over
>> the
>> +previous 7 bytes. Whether to check this CRC8 or not is dependent on
>> +CONFIG_NET_ETHADDR_EEPROM_CRC8.
>> +
>> +Layout example:
>> +
>> +00000000  21 4d 61 67 69 63 2e 21  01 23 45 67 89 ab ff c0
>> |!Magic.!.#Eg....|
>> +
>> +where the Header magic (!Magic.!) is spread over the first 8 bytes, and
>> the MAC
>> +address '01-23-45-67-89-ab' for the first interface (0xff) with the CRC8
>> +checksum 0xc0.
>> +
>>   -------
>>    Usage
>>   -------
>> diff --git a/net/Kconfig b/net/Kconfig
>> index a44a783..aced51e 100644
>> --- a/net/Kconfig
>> +++ b/net/Kconfig
>> @@ -7,6 +7,64 @@ menuconfig NET
>>
>>   if NET
>>
>> +config NET_ETHADDR_EEPROM
>> +       bool "Get ethaddr from eeprom"
>> +       help
>> +         Selecting this will try to get the Ethernet address from an
>> onboard
>> +         EEPROM and set into the environment if and only if the
>> environment
>> +         does currently not already hold a MAC address. For more
>> information
>> +         see doc/README.enetaddr.
>> +
>> +config NET_ETHADDR_EEPROM_I2C
>> +       depends on NET_ETHADDR_EEPROM
>> +       bool "EEPROM on I2C bus"
>> +       help
>> +         This switch enables checks for an EEPROM on the I2C bus.
>> Naturally
>> +         this will only work if there is an actual EEPROM connected on
>> the
>> +         I2C bus and the bus and device are properly configured via the
>> +         options below.
>> +
>> +config NET_ETHADDR_EEPROM_I2C_BUS
>> +       depends on NET_ETHADDR_EEPROM_I2C
>> +       int "I2C bus"
>> +       default 0
>> +       help
>> +         Select the bus on which the EEPROM is present, defaults to bus
>> 0.
>> +
>> +config NET_ETHADDR_EEPROM_I2C_ADDR
>> +       depends on NET_ETHADDR_EEPROM_I2C
>> +       hex "eeprom address"
>> +       default 0x50
>> +       help
>> +         Select the address of the eeprom, defaults to address 0x50.
>> +
>> +config NET_ETHADDR_EEPROM_I2C_ADDRLEN
>> +       depends on NET_ETHADDR_EEPROM_I2C
>> +       int "eeprom address length"
>> +       default 1
>> +       help
>> +         Number of bytes to be used for the I2C address length. Typically
>> 1,
>> +         2 for large memories, 0 for register type devices with only one
>> +         register.
>> +
>> +config NET_ETHADDR_EEPROM_OFFSET
>> +       depends on NET_ETHADDR_EEPROM
>> +       int "EEPROM offset"
>> +       default 8
>> +       help
>> +         Select the byte offset of the MAC address within the page,
>> +         defaults to byte 8.
>> +
>> +config NET_ETHADDR_EEPROM_CRC8
>> +       depends on NET_ETHADDR_EEPROM
>> +       bool "Check CRC8 of MAC"
>> +       default y
>> +       help
>> +         Optionally, it is possible to run a CRC-8-CCITT check on the MAC
>> +         address. To do so, the MAC address is stored with a CRC8 byte
>> append.
>> +         This option enables the CRC check of the MAC address against the
>> CRC
>> +         byte.
>> +
>>   config NET_RANDOM_ETHADDR
>>         bool "Random ethaddr if unset"
>>         select LIB_RAND
>>
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