Messages in this thread | | | Date | Mon, 16 Nov 2009 10:57:00 +0000 | From | Philip Downer <> | Subject | Re: firmware loading interface |
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Arnd Bergmann wrote: > 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. >
Thats correct.
> 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.
Thank you for this suggestion and for the warning about 32bit, we are in fact implementing a character device and could use this method.
Thanks,
Philip Downer
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