On Tue, Apr 14, 2015 at 10:08 AM, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, Apr 14, 2015 at 05:44:55PM +0800, Kweh, Hock Leong wrote: >> From: "Kweh, Hock Leong" <hock.leong.kweh@xxxxxxxxx> >> >> Introduce this new API for loading firmware from a specific location >> instead of /lib/firmware/ by providing a full path to the firmware >> file. > > Ick, why would we want this? > Because this mechanism should still work even if /lib is unwriteable (e.g it's on squashfs or a read-only NFS root). In this regard, UEFI capsules are very much unlike firmware_class firmware. firmware_class firmwise is kind of like device drivers; it generally comes from the same vendor as your kernel image and /lib/modules, and it can be updated by the same mechanism. UEFI capsules, on the other hand, are one-time things that should be loaded at the explicit request of the admin. There is no reason whatsoever that they should exist on persistent storage, and, in fact, there's a very good reason that they should not. On little embedded devices, which will apparently be the initial users of this code, keeping the capsules around is a waste of valuable space. This is why I think that the right approach would be to avoid using firmware_class entirely for this. IMO a simple_char device would be the way to go (hint hint...) but other simple approaches are certainly possible. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
