[OE-core] [PATCH] wic: add UEFI kernel as UEFI stub

[Maxim Uvarov]

On Mon, 13 Jan 2020 at 16:57, Paul Barker <paul at betafive.co.uk> wrote:
>
> On Sat, 4 Jan 2020, at 20:07, Maxim Uvarov wrote:
> > Linux kernel can be compiled as UEFI stub and loaded directly
> > with UEFI firmware without grub or other UEFI shell.
> >
> > Tested with wic file:
> > bootloader  --ptable gpt --timeout=0  --append="rootwait"
> > part /boot --source bootimg-efi --sourceparams="loader=kernel" \
> >  --ondisk sda  --fstype=vfat --label bootfs \
> >   --active --align 1024 --use-uuid
> > part / --source rootfs --fstype=ext4 --label rootfs \
> >   --align 1024 --exclude-path boot/ --use-label
> > The same wic file for armv7, armv8 and x86_64.
> >
> > Signed-off-by: Maxim Uvarov <maxim.uvarov at linaro.org>
> > ---
> >  scripts/lib/wic/plugins/source/bootimg-efi.py | 27 +++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> >
> > diff --git a/scripts/lib/wic/plugins/source/bootimg-efi.py
> > b/scripts/lib/wic/plugins/source/bootimg-efi.py
> > index 2cfdc10ecd..a39d852f6a 100644
> > --- a/scripts/lib/wic/plugins/source/bootimg-efi.py
> > +++ b/scripts/lib/wic/plugins/source/bootimg-efi.py
> > @@ -13,6 +13,7 @@
> >  import logging
> >  import os
> >  import shutil
> > +import re
> >
> >  from wic import WicError
> >  from wic.engine import get_custom_config
> > @@ -204,6 +205,8 @@ class BootimgEFIPlugin(SourcePlugin):
> >                  cls.do_configure_grubefi(hdddir, creator, cr_workdir,
> > source_params)
> >              elif source_params['loader'] == 'systemd-boot':
> >                  cls.do_configure_systemdboot(hdddir, creator,
> > cr_workdir, source_params)
> > +            elif source_params['loader'] == 'kernel':
> > +                return
> >              else:
> >                  raise WicError("unrecognized bootimg-efi loader: %s" %
> > source_params['loader'])
> >          except KeyError:
> > @@ -243,6 +246,7 @@ class BootimgEFIPlugin(SourcePlugin):
> >              if source_params['loader'] == 'grub-efi':
> >                  shutil.copyfile("%s/hdd/boot/EFI/BOOT/grub.cfg" %
> > cr_workdir,
> >                                  "%s/grub.cfg" % cr_workdir)
> > +
> >                  for mod in [x for x in os.listdir(kernel_dir) if
> > x.startswith("grub-efi-")]:
> >                      cp_cmd = "cp %s/%s %s/EFI/BOOT/%s" % (kernel_dir,
> > mod, hdddir, mod[9:])
> >                      exec_cmd(cp_cmd, True)
> > @@ -252,6 +256,29 @@ class BootimgEFIPlugin(SourcePlugin):
> >                  for mod in [x for x in os.listdir(kernel_dir) if
> > x.startswith("systemd-")]:
> >                      cp_cmd = "cp %s/%s %s/EFI/BOOT/%s" % (kernel_dir,
> > mod, hdddir, mod[8:])
> >                      exec_cmd(cp_cmd, True)
> > +            elif source_params['loader'] == 'kernel':
>
> How about "uefi-stub" instead of just "kernel" here so it's more explicit?
>

It's the same file were other uefi stubs are defined (grub and
systemd), so I named kernel uefi stub as kernel.

> > +                kernel = get_bitbake_var("KERNEL_IMAGETYPE")
> > +                if not kernel:
> > +                    raise WicError("Empty KERNEL_IMAGETYPE %s\n" %
> > target)
> > +                target = get_bitbake_var("TARGET_SYS")
> > +                if not target:
> > +                    raise WicError("Unknown arch (TARGET_SYS) %s\n" %
> > target)
> > +
> > +                if re.match("x86_64", target):
> > +                    kernel_efi_image = "bootx64.efi"
> > +                elif re.match('i.86', target):
> > +                    kernel_efi_image = "bootia32.efi"
> > +                elif re.match('aarch64', target):
> > +                    kernel_efi_image = "bootaa64.efi"
> > +                elif re.match('arm', target):
> > +                    kernel_efi_image = "bootarm.efi"
> > +                else:
> > +                    raise WicError("kernel efi is incompatible with
> > target %s" % target)
>
> Perhaps call this "UEFI stub kernel" instead of just "kernel efi" to make things clearer.
>

Ok.

> > +
> > +                for mod in [x for x in os.listdir(kernel_dir) if
> > x.startswith(kernel)]:
> > +                    cp_cmd = "cp %s/%s %s/EFI/BOOT/%s" % (kernel_dir,
> > mod, hdddir, kernel_efi_image)
> > +                    WicError("cp_cmd = %s" % cp_cmd);
>
> What's this WicError created here for?
>

Good catch. Debug print. Will send v2.

> > +                    exec_cmd(cp_cmd, True)
>
> Wouldn't this result in the destination file being overwritten each time through this loop? I guess you're just copying from the grub-efi implementation above though.
>

It's expected that there are no other uefi stubs and I just copy
kernel to /EFI/BOOT/bootxxx.efi.

Maxim.

> >              else:
> >                  raise WicError("unrecognized bootimg-efi loader: %s" %
> >                                 source_params['loader'])
> > --
> > 2.17.1
>
> --
> Paul Barker