I generally agree with Mark here. 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. > > > 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 think the basics of EFI (mostly those that EBBR requires) are sane and nice to boot multiple architectures as well. > > 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. > > > EFI_LOADER is required by EBBR, a new boot standard which aims to > > bring in UEFI protocols to U-Boot. But EBRR is not required for > > booting. U-Boot already provides support for FIT, the 'bootm' command > > and a suitable hand-off to Linux. EBRR has made the decision to create > > a parallel infrastructure, e.g. does not use FIT, nor U-Boot's signing > > infrastructure. > > EFI_LOADER is required to boot FreeBSD and OpenBSD on several > platforms as well as generic Linux distros. For example > OpenBSD/armv7, OpenBSD/arm64 and OpenBSD/riscv64 all rely on > EFI_LOADER to boot and have done so for the last 4 years. The fact > that ARM has embraced UEFI as an embedded boot standard and branded it > EBBR really isn't all that relevant. > > 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. > > > EBBR should be truly optional, enabled only by boards that use it. Most > > don't use it but it is enabled anyway. The default boot path should be > > one that makes use of the existing U-Boot support. > > I don't particularly care about EBBR myself, but EFI_LOADER should be > the default for as many armv7/arm64/riscv U-Boot targets as possible > to give users an easy way to choose the OS they want to run on their > machines. That is the best way to guarantee that vendors ship their > firmware with it enabled. > > > To try to retify this situation, this series adds a new Kconfig option > > for EBBR so that the naming is more explicit. Then EFI_LOADER is updated > > to depend on it. > > Isn't using the the term EBBR for non-ARM platforms misleading? Not really, we are discussing with RISC-V atm and having platfomrs being EBBR compliant. In essence we don't desire EBBR to be an Arm only thing. > EFI_LOADER is used much more widely. Anyway, I disagree with this > direction. > Same here > If size really matters here, we should look at reducing the EFI_LOADER > feature set to reduce the amount of code i adds, and maybe introduce > an EBBR option that can be enabled by those boards that desire full > EBBR compliance? +1 [...]
