ohos-image.bbclass: Define dtb_boot_files and extlinux_boot_files

* dtb_boot_files - converts dtb entries from KERNEL_DEVICETREE (assumed
  in DEPLOY/kernel) into IMAGE_BOOT_FILES ones (assuming destination is
  the root of the filesystem)
* extlinux_boot_files - converts extlinux files (assumed in
  DEPLOY/bootloader/extlinux) to IMAGE_BOOT_FILES entries (assuming
  destination is relative to the deploy directory of the extlinux files)

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-ohos-core/classes/ohos-image.bbclass

@@ -16,3 +16,25 @@ systemd_mask_getty () {
 }
 
 IMAGE_PREPROCESS_COMMAND_append = " ${@ 'systemd_mask_getty;' if bb.utils.contains('DISTRO_FEATURES', 'systemd', True, False, d) and not bb.utils.contains('IMAGE_FEATURES', 'stateless-rootfs', True, False, d) else ''}"
+
+# Convert all KERNEL_DEVICETREE enties to IMAGE_BOOT_FILES entries
+def dtb_boot_files(d):
+    k_dt = d.getVar('KERNEL_DEVICETREE')
+    if not k_dt:
+        return ''
+    return ' '.join(['kernel/{dtb};{dtb}'.format(dtb=dt) for dt in k_dt.split()])
+
+# Convert all extlinux files to IMAGE_BOOT_FILES entries
+def extlinux_boot_files(d):
+    import os
+    deploy_dir_image = d.getVar('DEPLOY_DIR_IMAGE')
+    deploy_extlinux_files = os.path.join(deploy_dir_image, 'bootloader/extlinux')
+    boot_files = []
+    for root, _, files in os.walk(deploy_extlinux_files):
+        for file in files:
+            src = os.path.relpath(os.path.join(root, file), deploy_dir_image)
+            dst = os.path.relpath(os.path.join(root, file), deploy_extlinux_files)
+            boot_files.append('{0};{1}'.format(src, dst))
+    if not boot_files:
+        return ''
+    return ' '.join(boot_files)