[OE-core] [PATCH] grub-efi-cfg: enable per-label APPEND override

[Rich Persaud]

For legacy bios boot configurations, syslinux supports multiple
labels with per-label APPEND definitions.  grub-efi-cfg supports
multiple labels, but only a single APPEND definition.

Enable optional per-label APPEND definitions for grub EFI, with
variable names prefixed by "grub_" to isolate grub definitions from
syslinux defintions.

Example use from an ISO image recipe that inherits grub-efi-cfg:

 LABELS_LIVE="foo bar"
 APPEND_grub_foo = "linuxcmdline"

No change in behavior for those using APPEND without overrides.

Signed-off-by: Rich Persaud <rp at stacktrust.org>
---
 meta/classes/grub-efi-cfg.bbclass | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meta/classes/grub-efi-cfg.bbclass b/meta/classes/grub-efi-cfg.bbclass
index 8b5ff20c72..3a2cdd698b 100644
--- a/meta/classes/grub-efi-cfg.bbclass
+++ b/meta/classes/grub-efi-cfg.bbclass
@@ -88,6 +88,12 @@ python build_efi_cfg() {
     for label in labels.split():
         localdata = d.createCopy()
 
+        overrides = localdata.getVar('OVERRIDES')
+        if not overrides:
+            bb.fatal('OVERRIDES not defined')
+
+        localdata.setVar('OVERRIDES', 'grub_' + label + ':' + overrides)
+
         for btype in btypes:
             cfgfile.write('\nmenuentry \'%s%s\'{\n' % (label, btype[0]))
             lb = label
-- 
2.20.1