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

[Maxim Uvarov]

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':
+                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)
+
+                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);
+                    exec_cmd(cp_cmd, True)
             else:
                 raise WicError("unrecognized bootimg-efi loader: %s" %
                                source_params['loader'])
-- 
2.17.1