On Mon, Nov 3, 2014 at 3:02 PM, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Mon, Nov 03, 2014 at 01:32:46PM -0800, Andy Lutomirski wrote: >> On Mon, Nov 3, 2014 at 1:27 PM, Greg Kroah-Hartman >> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> > On Mon, Nov 03, 2014 at 11:33:23AM -0800, Andy Lutomirski wrote: >> >> On 11/02/2014 07:07 PM, Kweh Hock Leong wrote: >> >> > From: "Kweh, Hock Leong" <hock.leong.kweh-ral2JQCrhuEAvxtiuMwx3w@xxxxxxxxxxxxxxxx> >> >> > >> >> > Hi Guys, >> >> > >> >> > This patchset is created on top of "efi: Capsule update support" patch: >> >> > http://permalink.gmane.org/gmane.linux.kernel.efi/4837 >> >> > >> >> > It leverages the request_firmware_nowait() to expose the user helper interface for user to upload the capsule binary and calling the >> >> > efi_capsule_update() API to pass the binary to EFI firmware. >> >> >> >> I don't get it. Why is the firmware interface at all reasonable for >> >> uploading capsules? >> > >> > Tradition dictates that BIOS updates go through the firmware interface, >> > that way you don't have to write a new userspace tool, which is a good >> > thing. >> > >> >> The firmware interface makes sense for nonvolatile firmware where >> >> hotplugging something or otherwise loading a driver needs a blob. >> > >> > Or BIOS data. We've been doing it this way for a long time now. >> >> On what system? Dell? > > Yes. > >> IMO this sucks from a UI point of view. When I install wifi firmware, >> I expect to stick it somewhere and have the driver find it, because >> the driver knows exactly when it needs the firmware. When I update my >> BIOS, I want to click a button or type a command and update my bios. > > I agree, it should be "triggered" by something, not just automagically > loaded whenever the kernel randomly looks for it. > >> >> But uploading an EFI capsule is an *action*, not something that should >> >> happen transparently. If there's an EFI firmware update available and >> >> the user wants to install it, then the userspace tool should install it, >> >> and it shouldn't hang around in /lib/firmware. In fact, you shouldn't >> >> even need /lib to be on writable media to use this. >> > >> > What does /lib have to do with this? >> >> Where else does the file come from, given that udev no longer supports >> userspace firmware loading? Is there really some pre-existing tool >> that pokes it into the sysfs firmware class thing? > > Well, you can specify other locations than /lib/firmware/ for firmware > updates, but yes, you are right, it should be in /lib somewhere. But > /lib doesn't need to be writable, it's a read-only file. > I assume that whoever downloaded the firmware update will want to install it, right? I don't really expect distros to ship EFI capsules in packages that install to /lib/firmware. Won't there be userspace code that either installs a capsule from some URL or uses some future magical find-my-firmware service? >> Since EFI capsules are apparently on their way to becoming a >> ubiquitous mechanism, I think it might be time to rethink >> request_firmware for this. > > What do you suggest instead? A "custom" sysfs file? What is going to > trigger it to be loaded? A userspace script that someone else has to > write? :) Some ioctl on /dev/efi_capsule seems reasonable to me, or a new script that uses a custom sysfs file. Isn't the Dell thing already a rather custom script? You write to a custom sysfs file ("rbu_image_type", I think) and then the handler for that file calls request_firmware. I think that we can handle a very small C program or script that uploads the EFI capsule. Also, FWIW, I think that there are EFI capsules that aren't firmware updates. For example, IIRC there's some mechansim that allows you to pass data to the next OS that boots via a capsule. It's probably buggy on every motherboard in existence, but if it ever worked, using it through /lib/firmware would make no sense. --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
