On Wed, Apr 29, 2015 at 2:39 PM, James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 2015-04-29 at 14:36 -0700, Andy Lutomirski wrote: >> On Wed, Apr 29, 2015 at 2:35 PM, James Bottomley >> <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote: >> > On Wed, 2015-04-29 at 11:23 +0000, Kweh, Hock Leong wrote: >> >> I agree with James. Due to different people may have different needs. But >> >> from our side, we would just like to have a simple interface for us to upload >> >> the efi capsule and perform update. We do not have any use case or need >> >> to get info from QueryCapsuleUpdate(). Let me give a suggestion here: >> >> please allow me to focus on deliver this simple loading interface and >> >> upstream it. Then later whoever has the actual use case or needs on the ioctl >> >> implementation, he or she could enhance base on this simple loading interface. >> >> What do you guys think? >> >> >> >> Let me summarize the latest design idea: >> >> - No longer leverage on firmware class but use misc device >> >> - Do not use platform device but use device_create() >> >> - User just need to perform "cat file.bin > /sys/.../capsule_loader" in the shell >> >> - File operation functions include: open(), read(), write() and flush() >> >> - Perform mutex lock in open() then release the mutex in flush() for avoiding >> >> race condition / concurrent loading >> >> - Perform the capsule update and error return at flush() function >> >> >> >> Is there anything I missed? Any one still have concern with this idea? >> >> Thanks for providing the ideas as well as the review. >> > >> > I think that's pretty much it. >> > >> > Why don't you let me construct a straw man patch. It's going to be a >> > bit controversial because it involves adding flush operations to sysfs >> > and kernfs, slicing apart firmware_class.c to extract the transaction >> > handling stuff and creating an new efi update capsule file which makes >> > use of it. >> > >> > Once we have code, we at least have something more concrete to argue >> > over. >> >> Would it be worth checking whether busybox is also okay with it first? >> (Sorry to be a naysayer.) >> >> It would be a shame if we do all this to keep the userspace footprint >> light and then it doesn't work for non-coreutils userspace. > > I don't think so, because we can fix busybox if it's a problem. The > embedded people wanting this control the tool space, so they can decide > to use the fixed version. > > So yes, someone should check and fix busybox cat if broken, but no, it's > not a blocker. It's still a bit unfortunate that: #!/bin/sh cat "$1" >/sys/whatever if [ "$?" != "0" ]; then echo "It didn't work because" ... exit 1 fi echo "It worked! Go reboot if needed." exit 0 will only work sometimes. Will people really test this on their target implementation of cat? I agree that making this possible with just shell is nice, but I'm less happy about it if it'll be unreliable. --Andy -- Andy Lutomirski AMA Capital Management, LLC -- 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
