lookup-order.rst (918B)
1===================== 2Firmware lookup order 3===================== 4 5Different functionality is available to enable firmware to be found. 6Below is chronological order of how firmware will be looked for once 7a driver issues a firmware API call. 8 9* The ''Built-in firmware'' is checked first, if the firmware is present we 10 return it immediately 11* The ''Firmware cache'' is looked at next. If the firmware is found we 12 return it immediately 13* The ''Direct filesystem lookup'' is performed next, if found we 14 return it immediately 15* The ''Platform firmware fallback'' is performed next, but only when 16 firmware_request_platform() is used, if found we return it immediately 17* If no firmware has been found and the fallback mechanism was enabled 18 the sysfs interface is created. After this either a kobject uevent 19 is issued or the custom firmware loading is relied upon for firmware 20 loading up to the timeout value.