scripts/oe-setup-builddir: add a check that TEMPLATECONF is valid

specifically that ../../layer.conf exists, and that second-from-last
component in the path is 'templates'.

This requires tweaking template.conf creation in eSDK bbclass, as
we need to ensure that the path in it is valid, and exists
(which may not be the case if the SDK is poky-based).

(From OE-Core rev: c6f2b57be8893ee58f20cc29d8ec3a5a6edf7c07)

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes-recipe/populate_sdk_ext.bbclass

@@ -438,7 +438,8 @@ python copy_buildsystem () {
     else:
         # Write a templateconf.cfg
         with open(baseoutpath + '/conf/templateconf.cfg', 'w') as f:
-            f.write('meta/conf\n')
+            f.write('meta/conf/templates/default\n')
+        os.makedirs(os.path.join(baseoutpath, core_meta_subdir, 'conf/templates/default'), exist_ok=True)
 
     # Ensure any variables set from the external environment (by way of
     # BB_ENV_PASSTHROUGH_ADDITIONS) are set in the SDK's configuration

scripts/oe-setup-builddir

@@ -61,6 +61,11 @@ if [ -n "$TEMPLATECONF" ]; then
             echo >&2 "Error: TEMPLATECONF value points to nonexistent directory '$TEMPLATECONF'"
             exit 1
         fi
+        templatesdir=$(python3 -c "import sys; print(sys.argv[1].strip('/').split('/')[-2])" $TEMPLATECONF)
+        if [ ! -f "$TEMPLATECONF/../../layer.conf" -o $templatesdir != "templates" ]; then
+            echo >&2 "Error: TEMPLATECONF value (which is $TEMPLATECONF) must point to meta-some-layer/conf/templates/template-name"
+            exit 1
+        fi
     fi
     OECORELAYERCONF="$TEMPLATECONF/bblayers.conf.sample"
     OECORELOCALCONF="$TEMPLATECONF/local.conf.sample"