On Mar 6, 2015 4:20 AM, "Kweh, Hock Leong" <hock.leong.kweh@xxxxxxxxx> wrote: > > > -----Original Message----- > > From: Andy Lutomirski [mailto:luto@xxxxxxxxxxxxxx] > > Sent: Friday, March 06, 2015 7:09 AM > > > > On Mar 5, 2015 1:19 AM, "Kweh, Hock Leong" <hock.leong.kweh@xxxxxxxxx> > > wrote: > > > > > > > > This really is not a big deal. User should cope with it. > > > > > > > > No, it's a big deal, and the user should not cope. > > > > > > > > The user *should not* be required to have write access to anything in > > > > /lib to install a UEFI capsule that they download from their > > > > motherboard vendor's website. /lib belongs to the distro, and UEFI > > > > capsules do not belong to the distro. In this regard, UEFI capsules > > > > are completely unlike your wireless card firmware, your cpu microcode, > > > > etc. > > > > > > > > Imagine systems using NFS root, Atomic-style systems (e.g. ostree), > > > > systems that boot off squashfs, etc. They should still be able to > > > > load capsules. The basic user interface that should work is: > > > > > > > > # uefi-load-capsule /path/to/capsule > > > > > > > > or: > > > > > > > > # uefi-load-capsule - </path/to/capsule > > > > > > > > I don't really care how uefi-load-capsule is implemented, as long as > > > > it's straightforward, because people will screw it up if it isn't > > > > straightforward. > > > > > > > > Why is it so hard to have a file in sysfs that you write the capsule > > > > to using *cat* (not echo) and that will return an error code if cat > > > > fails? Is it because you don't know where the end of the capsule is? > > > > if so, ioctl is designed for exactly this purpose. > > > > > > > > TBH, I find this thread kind of ridiculous. The problem that you're > > > > trying to solve is extremely simple, the functionality that userspace > > > > needs is trivial, and all of these complex proposals for how it should > > > > work are an artifact of the fact that the kernel-internal interfaces > > > > you're using for it are not well suited to the problem at hand. > > > > > > > > --Andy > > > > > > Sorry, I may not catch your point correctly. Are you trying to tell that > > > a "normal" user can perform efi capsule update. But a "normal" user > > > does not have the right to install or copy the capsule binary into > > > "/lib/firmware/". So, there is a need to make this capsule module to > > > allow uploading the capsule binary at any path or location other than > > > "/lib/firmware/". > > > > > > Is this what you mean? > > > > No. Only root should be able to load capsules, but even root may not > > be able to write to /lib. > > > > --Andy > > > > Okay, I accept that only root user can perform the load capsule. It is new > to me that root user may not have the access right to "/lib/firmware". > > But I remember you do mention that CPU micro code and wifi firmware > they are different and able to write in /lib/firmware. I am curious why > efi capsule binary have such a restriction. What is preventing it being > write to that location? > It has to do with where the firmware comes from. When someone prepares Linux fs image, they put user code, a kernel (usually), all modules that might be needed, and all firmware that's likely to be needed into /. This might come from the distro or a company-wide image. If a normal firmware firmware file needs an update, it's just like updating a driver or a library -- / will be updated by whatever mechanism is in use. Nonvolatile firmware is different. The update isn't needed on subsequent boots, and it could be much less generic than a driver. For example, a capsule could contain a boot splash screen image that says "this is computer #27." Updating the system image to do this makes little sense. Instead it'll be a one-time thing done by root. --Andy > I even went to check out the FHS: > http://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard > I do not find any restriction calling out for that. > > Would you mind to educate me on that? > Thanks. > > > Regards, > Wilson > -- 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
