Hi Tom, On Mon, 28 Jun 2021 at 11:27, Tom Rini <tr...@konsulko.com> wrote: > > On Mon, Jun 28, 2021 at 10:26:35AM -0600, Simon Glass wrote: > > Hi Heinrich, > > > > On Mon, 28 Jun 2021 at 09:20, Heinrich Schuchardt <xypron.g...@gmx.de> > > wrote: > > > > > > On 6/28/21 4:18 PM, Simon Glass wrote: > > > > Hi Tom, Mark, > > > > > > > > On Mon, 28 Jun 2021 at 07:37, Tom Rini <tr...@konsulko.com> wrote: > > > >> > > > >> On Mon, Jun 28, 2021 at 10:38:50AM +0200, Mark Kettenis wrote: > > > >>>> From: Simon Glass <s...@chromium.org> > > > >>>> Date: Sun, 27 Jun 2021 19:48:34 -0600 > > > >>>> > > > >>>> It has come to light that EFI_LOADER adds an extraordinary amount of > > > >>>> code to U-Boot. For example, with nokia_rx51 the size delta is about > > > >>>> 90KB. About 170 boards explicitly disable the option, but is is clear > > > >>>> that many more could, thus saving image size and boot time. > > > >>> > > > >>> EFI_LOADER used to be a lot smaller. It is great to see that over the > > > >>> years UEFI support has become more complete, but a lot of that new > > > >>> code implements features that are not at all essential for just > > > >>> booting an OS from storage. If that growth leads to the suggestion to > > > >>> disable EFI_LOADER completely by default, we're putting the cart > > > >>> before the horse. > > > >> > > > >> Well, I see I forgot to prefix my patch with RFC, but I hadn't found > > > >> EFI_LOADER being used in the wild on armv7, but wasn't sure about the > > > >> BSD families. I did see that Debian doesn't use it, and that Armbian > > > >> doesn't even use it on aarch64. > > > >> > > > >>>> The current situation is affecting U-Boot's image as a svelt > > > >>>> bootloader. > > > >>> > > > >>> Really? I know UEFI has a bad reputation in the Open Source world, > > > >>> and some of its Microsoft-isms are really annoying (yay UCS-2). But > > > >>> it works, it provides a standardized approach across several platforms > > > >>> (ARMv7, AMRv8, RISC-V) and the industry seems to like it. Personally > > > >>> I'd wish the industry had standardized on Open Firmware instead, but > > > >>> that ship sailed a long time ago... > > > >>> > > > >>> I find it hard to imagine that 90k is a serious amount of storage for > > > >>> something that is going to include a multi-MB Linux kernel. This > > > >>> isn't code that lives in SPL or TPL where severe size restrictions > > > >>> apply. > > > >> > > > >> In one of those cases where I need to pop back in to the other (Nokia > > > >> N900 specific) thread and see if the big size reduction really was just > > > >> disabling EFI_LOADER, it's perhaps just one of those "fun" things about > > > >> Kconfig and anything other than "make oldconfig" for spotting new > > > >> config > > > >> options that default to enabled. > > > > > > > > Yes it will be interesting to see what you find there. My results on > > > > nokia_rx51 were something like this: > > > > > > > > default > > > > arm: (for 1/1 boards) all +129370.0 bss +1136.0 data +7399.0 > > > > rodata +10989.0 text +109846.0 > > > > > > > > without ebbr > > > > arm: (for 1/1 boards) all +38460.0 bss +1040.0 data +2375.0 > > > > rodata +5333.0 text +29712.0 > > > > > > > > with various other things: > > > > CONFIG_OF_LIBFDT_ASSUME_MASK=7 > > > > # CONFIG_OF_TRANSLATE is not set > > > > # CONFIG_SIMPLE_BUS is not set > > > > # CONFIG_TI_SYSC is not set > > > > # CONFIG_CMD_FDT is not set > > > > > > > > arm: (for 1/1 boards) all +19170.0 bss -16.0 data +360.0 rodata > > > > +3274.0 text +15552.0 > > > > > > > > (Mark, in the same email:) > > > >>> FIT simply isn't fit for purpose (pun intended). It only really works > > > >>> for booting Linux, and forces people to combine u-boot, kernel, > > > >>> initial ramdisk and other firmware components into a single image. > > > >>> That is really undesirable as: > > > >>> - This makes it sigificantly harder to update individual components of > > > >>> such an image. Making it hard to update a kernel is obviously a > > > >>> serious security risk. > > > >>> - This makes it impossible to build an OS install image that works om > > > >>> multiple boards/SoCs. > > > > > > > > > > > > I would really like to understand this better. The whole thing is a > > > > complete mystery to me. > > > > > > > > Firstly I have sometimes fiddled with booting other OSes using FIT. It > > > > seemed OK. I can't see why it only works with Linux. > > > > > > > > Secondly, I don't expect that U-Boot itself would be in the FIT. > > > > > > > > Thirdly, do you really want the kernel and initrd to be separate? At > > > > least in the systems I have used, they are built together, even having > > > > the same name, e.g.: > > > > > > > > initrd.img-5.10.40-1rodete1-amd64 > > > > System.map-5.10.40-1rodete1-amd64 > > > > vmlinuz-5.10.28-1rodete2-amd64 > > > > > > I have not hit any distro that builds FIT images. All install vmlinux > > > and initrd as separate files. > > > > > > Why would you want to change that? > > > > Well there is no point in having two files if one will do. Also it > > allows for a hash / signature check. > > The question of "how great would it be and how many problems would it > have solved if FIT images had become popular" is one for another time. > It will always have its use cases and users but never the broad adoption > many of us felt it should have. Bringing it up in this context won't > change that.
I see Peter's reply below so will make time to dig into this and understand the problems with FIT better. I feel that EFI comes with all sorts of problems so I'm far from convinced, at this point. Sorry. > > I'm saying this because I think there are some important technical > questions within U-Boot to resolve because the EFI loader part of U-Boot > is critical to our long term future. And DM is an important part of our > internal design and we're (probably later than I should have) pulling > out the parts that haven't been updated so that we can deliver on some > of the overall promise of DM better, too. Yes, migration has certainly been slow. As you know I mostly stopped pushing it a few years back when I saw all the reluctance. I'm very pleased you are taking that on and I think it will help a lot. If what you say comes to pass, it is even more important that EFI is more integrated, rather than being a bolt on. Thanks largely to Heinrich, the tests are in quite good shape, so refactoring should be feasible. Regards, Simon
