Hi Heinrich, On Wed, 5 Jun 2024 at 02:40, Heinrich Schuchardt <[email protected]> wrote: > > On 29.05.24 18:30, Simon Glass wrote: > > Hi, > > > > On Tue, 28 May 2024 at 18:38, E Shattow <[email protected]> wrote: > >> > >> Hi, > >> > >> On Tue, May 28, 2024 at 7:43 AM Heinrich Schuchardt > >> <[email protected]> wrote: > >>> > >>> In U-Boot EFI boot options can already specify both an EFI binary and > >>> an initrd. With this series we can additionally define the matching > >>> device-tree to be loaded in the boot option. > >>> > >>> With the last patch the boot manager will fall back the device-tree > >>> specified by $fdtfile in directories '/dtb/', '/', or '/dtb/current/' > >>> on the boot device if no device-tree is specified in the boot > >>> option or via a bootefi command parameter. > >>> > >> > >> As tested the $fdtfile environment variable has no effect on > >> global EFI boot when i.e. EFI/BOOT/BOOTRISCV64.EFI > >> on EFI System Partition and no user-added boot option; > >> $fdtfile env variable is not used with "mmc 0" or whichever > >> global boot option is enabled by default in the boot order. > >> > >> Adding a boot option for EFI/BOOT/BOOTRISCV64.EFI > >> and giving this priority in the boot order allows $fdtfile to > >> be effective here. This is consistent with what is described > >> by the series. Would the global EFI boot also get support > >> for $fdtfile either with this or a later series? > >> > >>> v2: > >>> Update efi_dp_concat() instead of new function efi_dp_merge(). > >>> Carve out a function efi_load_option_dp_join() which we can > >>> use both for the eficonfig and the efidebug command. > >>> Rename variables id_dp, final_dp_size. > >>> Rename create_initrd_dp() to create_lo_dp_part(). > >>> Use enum as parameter for create_lo_dp_part(). > >>> Put all related changes into one patch. > >>> > >>> Heinrich Schuchardt (8): > >>> efi_loader: allow concatenation with contained end node > >>> cmd: eficonfig: add support for setting fdt > >>> cmd: efidebug: add support for setting fdt > >>> efi_loader: load device-tree specified in boot option > >>> efi_loader: move distro_efi_get_fdt_name() > >>> efi_loader: return binary from efi_dp_from_lo() > >>> efi_loader: export efi_load_image_from_path > >>> efi_loader: load distro dtb in bootmgr > >>> > >>> boot/bootmeth_efi.c | 60 +--------- > >>> cmd/eficonfig.c | 83 +++++++++---- > >>> cmd/efidebug.c | 130 +++++++++++++++------ > >>> include/efi_loader.h | 24 +++- > >>> lib/efi_loader/Makefile | 1 + > >>> lib/efi_loader/efi_bootbin.c | 2 +- > >>> lib/efi_loader/efi_bootmgr.c | 75 +++++++++++- > >>> lib/efi_loader/efi_boottime.c | 3 +- > >>> lib/efi_loader/efi_device_path.c | 40 ++++--- > >>> lib/efi_loader/efi_device_path_utilities.c | 2 +- > >>> lib/efi_loader/efi_fdt.c | 117 +++++++++++++++++++ > >>> lib/efi_loader/efi_helper.c | 44 +++++++ > >>> 12 files changed, 445 insertions(+), 136 deletions(-) > >>> create mode 100644 lib/efi_loader/efi_fdt.c > >>> > >>> -- > >>> 2.43.0 > >>> > >> > > > > Can we use the best-match compatible approach as expected by the new > > 'make image.fit' in Linux? > > > > Filenames should be deprecated IMO. I am happy to help work on how to > > do that if you agree. > > Hello Simon, > > It is the OS that creates boot options. The OS can determine the exact > dtb file based on the compatible string and the kernel version once per > kernel upgrade. This is much more efficient than doing the same on every > boot. > > Replacing $fdtfile by a matching logic could make sense. But please > consider the effect on boot time if have to read through more than 1000 > arm64 dtbs with U-Boot's non-caching file-system drivers.
The suggested option here is to use FIT, which is very fast at scanning the files. Please see [1] Failing that, we could implement a way (in FIT) of specifying that the FDT is in an external file. In that case FIT would become a mapping from compatible strings to filenames. Regards, Simon [1] https://github.com/open-source-firmware/flat-image-tree/blob/main/source/chapter3-usage.rst
