Conclusive EEPROM format

Table of contents:

EEPROM address

Each of the boards contains at least one EEPROM memory chip. The EEPROM SYS_I2C bus addresses, specified in the hardware documentation of each board, are as follows:

• KSTR-SAMA5D27 - 0x50

• RCHD-PF - 0x50

• WHLE-LS1 - 0x56

Please consult the hardware documentation if the address is not listed here, or the EEPROM cannot be reached.

EEPROM memory format and structure

EEPROM memory size and protected area

Each of the Conclusive boards has an EEPROM memory of size of 32-64KB. Memory area range of 0 to 2KB is reserved for board identification and cannot be erased or overwritten.

ONIE TLV

ONIE TLV is an industry standard format of marking hardware-specific information in the EEPROM memory. All Conclusive Engineering devices use it.

EEPROM memory format structure is binary and size-oriented. The EEPROM memory starts with a special header containing 'TlvInfo' string and other information required for parsing the rest of the memory.

Each field is stored in a triplet of 'Field ID', 'Field Size', 'Field Value'. Format of 'Field Value' may differ based on 'Field ID'. For securing the ONIE TLV EEPROM all data is protected using CRC32 checksum that is modified by any edit.

For more specific information about the ONIE TLV format please follow to ONIE website EEPROM Information Format.

Here is a real example of how the EEPROM memory is programmed on the Conclusive Devices KSTR-SAMA5D27 board.

U-boot

U-Boot bootloader is a prevailing option on most Conclusive Devices products. U-Boot by default is configured to use ONIE TLV EEPROM for onboard device information like MAC addresses for built-in network cards.
It is possible to read, edit or delete TLV values using U-Boot.

After editing and writing TLV data please restart the board to ensure that values presented by U-Boot are refreshed.

Read

To read the ONIE TLV EEPROM from U-Boot, interrupt the startup process by pressing any key on the serial console and type in the command tlv:

Edit

Before doing any changes to TLV information please backup the original contents. Failing to do so may result in a malfunctioning board.

To edit the ONIE TLV EEPROM from U-Boot, interrupt the startup process. Type the tlv list command to list valid Field IDs.

EEPROM memory is write protected. To disable the write protect lock and write to EEPROM memory you should use the Conclusive Devices development cable connector.