yocto-kernel: add support for destroying recipe-space kernel features

Add a yocto-kernel command allowing users to destroy a recipe-space
kernel feature local to a particular BSP.  The removed feature is
subsequently no longer available for the normal feature addition and
removal yocto-kernel commands.

(From meta-yocto rev: faa18f56d9412694f2c8e0b0c09e751cb7f3a743)

Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 110 insertions, 0 deletions

diff --git a/scripts/lib/bsp/help.py b/scripts/lib/bsp/help.py
index d7c0360a7a..427b5a00e9 100644
--- a/scripts/lib/bsp/help.py
+++ b/scripts/lib/bsp/help.py
@@ -389,6 +389,7 @@ yocto_kernel_usage = """
    features list     List the features available to BSPs
    feature describe  Describe a particular feature
    feature create    Create a new BSP-local feature
+   feature destroy   Remove a BSP-local feature
 
  See 'yocto-kernel help COMMAND' for more information on a specific command.
 
@@ -788,6 +789,36 @@ DESCRIPTION
     (which for the time being can be one of: 'all' or 'board').
 """
 
+
+yocto_kernel_feature_destroy_usage = """
+
+ Destroy a recipe-space kernel feature in a BSP
+
+ usage: yocto-kernel feature destroy <bsp-name> feature.scc
+
+ This command destroys a kernel feature defined in the specified BSP's
+ recipe-space kernel definition.
+"""
+
+
+yocto_kernel_feature_destroy_help = """
+
+NAME
+    yocto-kernel feature destroy <bsp-name> feature.scc - destroy a
+    recipe-space kernel feature in a BSP
+
+SYNOPSIS
+    yocto-kernel feature destroy <bsp-name> feature.scc
+
+DESCRIPTION
+    This command destroys a kernel feature defined in the specified
+    BSP's recipe-space kernel definition.  The named feature must end
+    with .scc and must not contain a feature directory to contain the
+    feature (this will be determined automatically).  If the kernel
+    feature is in use by a BSP, it can't be removed until the BSP
+    stops using it (see yocto-kernel feature rm to stop using it).
+"""
+
 ##
 # yocto-layer help and usage strings
 ##
diff --git a/scripts/lib/bsp/kernel.py b/scripts/lib/bsp/kernel.py
index ac6861e14b..fc1e6bdd08 100644
--- a/scripts/lib/bsp/kernel.py
+++ b/scripts/lib/bsp/kernel.py
@@ -910,6 +910,85 @@ def yocto_kernel_feature_create(scripts_path, machine, feature_items):
     print "\t%s" % feature_dirname + "/" + feature
 
 
+def feature_in_use(scripts_path, machine, feature):
+    """
+    Determine whether the specified feature is in use by the BSP.
+    Return True if so, False otherwise.
+    """
+    features = read_features(scripts_path, machine)
+    for f in features:
+        if f == feature:
+            return True
+    return False
+
+
+def feature_remove(scripts_path, machine, feature):
+    """
+    Remove the specified feature from the available recipe-space
+    features defined for the BSP.
+    """
+    features = read_features(scripts_path, machine)
+    new_features = []
+    for f in features:
+        if f == feature:
+            continue
+        new_features.append(f)
+    write_features(scripts_path, machine, new_features)
+
+
+def yocto_kernel_feature_destroy(scripts_path, machine, feature):
+    """
+    Remove a recipe-space kernel feature from a BSP.
+    """
+    if not check_feature_name(feature):
+        sys.exit(1)
+
+    if feature_in_use(scripts_path, machine, "features/" + feature) or \
+            feature_in_use(scripts_path, machine, "cfg/" + feature):
+        print "Feature %s is in use (use 'feature rm' to un-use it first), exiting" % feature
+        sys.exit(1)
+
+    filesdir = find_filesdir(scripts_path, machine)
+    if not filesdir:
+        print "Couldn't destroy feature (%s), no 'files' dir found" % feature
+        sys.exit(1)
+
+    feature_dirname = "features"
+    featdir = os.path.join(filesdir, feature_dirname)
+    if not os.path.exists(featdir):
+        print "Couldn't find feature directory (%s)" % feature_dirname
+        sys.exit(1)
+
+    feature_fqn = os.path.join(featdir, feature)
+    if not os.path.exists(feature_fqn):
+        feature_dirname = "cfg"
+        featdir = os.path.join(filesdir, feature_dirname)
+        if not os.path.exists(featdir):
+            print "Couldn't find feature directory (%s)" % feature_dirname
+            sys.exit(1)
+        feature_fqn = os.path.join(featdir, feature_filename)
+        if not os.path.exists(feature_fqn):
+            print "Couldn't find feature (%s)" % feature
+            sys.exit(1)
+
+    f = open(feature_fqn, "r")
+    lines = f.readlines()
+    for line in lines:
+        s = line.strip()
+        if s.startswith("patch ") or s.startswith("kconf "):
+            split_line = s.split()
+            filename = os.path.join(featdir, split_line[-1])
+            if os.path.exists(filename):
+                os.remove(filename)
+    f.close()
+    os.remove(feature_fqn)
+
+    feature_remove(scripts_path, machine, feature)
+
+    print "Removed feature:"
+    print "\t%s" % feature_dirname + "/" + feature
+
+
 def base_branches(context):
     """
     Return a list of the base branches found in the kernel git repo.