Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: firmware loading interface | Date | Fri, 13 Nov 2009 20:29:00 +0100 |
| |
On Friday 13 November 2009, Philip Downer wrote: > However our device will have flash to store the firmware in and, whilst > it looks as though it would be possible for us to use request_firmware > to provide occasional firmware upgrades from userspace, I can't find any > reference as to whether this is an accepted method for doing so. Could > someone please confirm for me whether or not it's a good idea to use > request_firmware for this, or perhaps point me at another standard > method for doing firmware updates from userspace?
The idea of request_firmware is that it helps you load the firmware into the device at initialization time so you can use it directly, without making the firmware blob a part of the kernel driver.
If I understand you correctly, you never need a firmware in user space in order to use the device, but only for flashing a new version into the nonvolatile memory.
The easiest way to do that would be an ioctl operation, if you are implementing a character or block device interface anyway. Just load the firmware into the RAM of a user application and call an ioctl with the pointer to the firmware as an argument, but don't use a data structure with a pointer in it, which would mess up 32 bit compatibility operation.
If you don't implement a character or block device, the chances are that you need something else besides an ioctl, depending on how an application would communicate with your hardware.
Arnd <><
| |