| ===================== |
| Firmware lookup order |
| ===================== |
| |
| Different functionality is available to enable firmware to be found. |
| Below is chronological order of how firmware will be looked for once |
| a driver issues a firmware API call. |
| |
| * The ''Built-in firmware'' is checked first, if the firmware is present we |
| return it immediately |
| * The ''Firmware cache'' is looked at next. If the firmware is found we |
| return it immediately |
| * The ''Direct filesystem lookup'' is performed next, if found we |
| return it immediately |
| * The ''Platform firmware fallback'' is performed next, but only when |
| firmware_request_platform() is used, if found we return it immediately |
| * If no firmware has been found and the fallback mechanism was enabled |
| the sysfs interface is created. After this either a kobject uevent |
| is issued or the custom firmware loading is relied upon for firmware |
| loading up to the timeout value. |
