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
- 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.