CompuLab EEPROM utility

This utility displays and updates EEPROM information. It works for any EEPROM, but has special support for Compulab SoMs by being aware of the EEPROM layout, and using that information to display the EEPROM contents in a human readable format.

The utility provides a WYSIWYG UI for updating EEPROM contents; the user can specify the target field by name, and provide the new value in the same formatting as displayed by the read command. The user can also clear a field by name. Direct offset/value mode of writing is also supported.

Finally, the utility can list accessible devices on i2c buses, or a more concise listing of just the EEPROM devices, depending on the available interfaces in the OS.

Example run:

# ./eeprom-util read 2 0x50
Major Revision                1.00
Minor Revision                0.00
1st MAC Address               00:01:c0:13:91:d0
2nd MAC Address               00:01:ca:12:91:d0
Production Date               29/Aug/2013
Serial Number                 ffffffffffff123456789abc
3rd MAC Address (WIFI)        ff:ff:ff:ff:ff:ff
4th MAC Address (Bluetooth)   ff:ff:ff:ff:ff:ff
Layout Version                02
Reserved fields               (83 bytes)
Product Name                  CM-FX6
Product Options #1            C1200QM-D2G-N0-
Product Options #2            ND0-U5-E-A-WB
Product Options #3
Reserved fields               (64 bytes)

# ./eeprom-util write fields 2 0x50 "Production Date=01/Jun/2014"
# ./eeprom-util clear fields 2 0x50 "Serial Number" "Minor Revision"

Requirements

The utility requires a Linux system with either /dev/i2c interface, or a loaded EEPROM driver (at24).

Building

To build the utility you can type one of the following:

• make - Only read functionality will be supported, system default linking type.

• make write - Enable the write capabilities, system default linking type.

• make static - Only read functionality, force static linking of libraries.

• make write_static - Enable the write capabilities, force static linking of libraries.

• make debug - Enable the write capabilities, compile with debug flags.

Adding custom EEPROM layouts

To add support for your custom EEPROM layouts do the following:

layout.c:

• Create a new struct field array with the fields of your layout.

  Each field must define a name, a short name, a size (in bytes) and a type.

  The available field’s types are listed under enum field_type in field.h.

  The total size of all fields must not exceed the defined EEPROM_SIZE in layout.h

• Update detect_layout() function to properly auto-detect your layout.

  Notice the value of LAYOUT_CHECK_BYTE. It is the offset of the "layout version" field.

• Update build_layout() function to select the fields array of your layout.

layout.h:

• Add the version or the name of your layout to enum layout_version

parser.c:

• (optional) Update parse_layout_version() to enable manual selection of your layout using the -l <layout_version> command line option.

Warning

Some features of the utility may not work correctly if your custom layout does not retain backward compatibility with existing Compulab layouts. To ensure full support, your custom layout should expand existing layouts only within the reserved fields area. In any case, try not to change the offset of the "Layout Version" field to avoid complicating the auto detection of your layout by the utility.