---
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
