Difference between revisions of "Novena/EEPROM"
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| 6 || (Random) || Gigabit MAC address || Random MAC address is generated on each boot | | 6 || (Random) || Gigabit MAC address || Random MAC address is generated on each boot | ||
| + | |- | ||
| + | | 2 || 0 || Feature bitmask || No features are enabled | ||
| + | |} | ||
| + | |||
| + | ==Feature bitmask== | ||
| + | There is a bitmask field that defines various board features. In this way, a single image can be shipped that supports various components. For example, a router might not have a display, but a laptop would need to have its LCD turned on. A bit is "1" if the feature is present (and needs to be enabled), and "0" if it is not present. Note that some values are mutually-exclusive (e.g. you can only have one kind of LVDS display attached). | ||
| + | {| class="wikitable sortable" | ||
| + | |+ Feature list | ||
| + | |- | ||
| + | ! scope="col" | Bit position | ||
| + | ! scope="col" | Feature | ||
| + | ! scope="col" | Description | ||
| + | ! scope="col" | Result if no EEPROM present | ||
| + | |- | ||
| + | | 1 || ES8328 Audio Codec | ||
| + | |- | ||
| + | | 2 || Battery board | ||
| + | |- | ||
| + | | 3 || Retina LVDS display | ||
| + | |- | ||
| + | | 4 || (Reserved: Other LVDS display) | ||
| + | |- | ||
| + | | 5 || Power Management Board | ||
|} | |} | ||
Revision as of 04:19, 27 September 2013
Novena has a utility EEPROM that can be used for storing device-specific data. This is optional, and default values will be used if it is blank / not present.
All multi-byte integers are in native host order.
Structure
| Size | Default Value | Description | Result if no EEPROM present |
|---|---|---|---|
| 6 | 'Novena' | Unterminated EEPROM signature | The EEPROM contents will not be used |
| 1 | 1 | Version number of EEPROM structure | The EEPROM contents will not be used |
| 1 | 0xff | Supported peripherals | All peripherals are assumed present |
| 4 | 0 | Device serial number | No change |
| 6 | (Random) | Gigabit MAC address | Random MAC address is generated on each boot |
| 2 | 0 | Feature bitmask | No features are enabled |
Feature bitmask
There is a bitmask field that defines various board features. In this way, a single image can be shipped that supports various components. For example, a router might not have a display, but a laptop would need to have its LCD turned on. A bit is "1" if the feature is present (and needs to be enabled), and "0" if it is not present. Note that some values are mutually-exclusive (e.g. you can only have one kind of LVDS display attached).
| Bit position | Feature | Description | Result if no EEPROM present |
|---|---|---|---|
| 1 | ES8328 Audio Codec | ||
| 2 | Battery board | ||
| 3 | Retina LVDS display | ||
| 4 | (Reserved: Other LVDS display) | ||
| 5 | Power Management Board |
