For cases where we need to apply a patch to an existing package, we should use FILESEXTRAPATHS, which includes new directories in the searching algorithm, making the extra file visible to BitBake, as shown here:
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}-${PV}:"
SRC_URI += "file://mypatch.patch"In the preceding example, THISDIR expands to the current directory, and PN and PV expand to the package name and package version, respectively. This new path is then included in the directories list used for file searching. The use of the _prepend operator is important as it guarantees that our provided file is used, even if a file with the same name is added in the lower priority layers in future.
BitBake assumes that every file with a .patch extension is a patch and applies them accordingly.
