initial buildroot for linux 5.15

package/protobuf-c/Config.in

@@ -0,0 +1,15 @@
+config BR2_PACKAGE_PROTOBUF_C
+	bool "protobuf-c"
+	depends on BR2_INSTALL_LIBSTDCPP
+	depends on BR2_TOOLCHAIN_HAS_THREADS
+	# host-protobuf only builds on certain architectures
+	depends on BR2_HOSTARCH = "x86_64" || BR2_HOSTARCH = "x86"
+	help
+	  Code generator and runtime libraries to use Protocol Buffers
+	  from pure C (not C++).
+
+	  https://github.com/protobuf-c/protobuf-c
+
+comment "protobuf-c needs a toolchain w/ C++, threads"
+	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_TOOLCHAIN_HAS_THREADS
+	depends on BR2_HOSTARCH = "x86_64" || BR2_HOSTARCH = "x86"

package/protobuf-c/protobuf-c.hash

@@ -0,0 +1,3 @@
+# Locally calculated
+sha256  1068bca1e9870e9492096f97c409cd15f10c5019c183e52ec6d53e8d18630cbf  protobuf-c-1.4.0.tar.gz
+sha256  20e800cad4550f4b19bb37fc9577dac21de13333ae66497c4c45ae489c35c34a  LICENSE

package/protobuf-c/protobuf-c.mk

@@ -0,0 +1,23 @@
+################################################################################
+#
+# protobuf-c
+#
+################################################################################
+
+PROTOBUF_C_VERSION = 1.4.0
+PROTOBUF_C_SITE = $(call github,protobuf-c,protobuf-c,v$(PROTOBUF_C_VERSION))
+PROTOBUF_C_DEPENDENCIES = host-protobuf-c
+HOST_PROTOBUF_C_DEPENDENCIES = host-protobuf host-pkgconf
+PROTOBUF_C_MAKE = $(MAKE1)
+PROTOBUF_C_CONF_OPTS = --disable-protoc
+PROTOBUF_C_INSTALL_STAGING = YES
+PROTOBUF_C_LICENSE = BSD-2-Clause
+PROTOBUF_C_LICENSE_FILES = LICENSE
+PROTOBUF_C_AUTORECONF = YES
+HOST_PROTOBUF_C_AUTORECONF = YES
+
+# host-protobuf needs c++11 (since 3.6.0)
+HOST_PROTOBUF_C_CONF_ENV += CXXFLAGS="$(HOST_CXXFLAGS) -std=c++11"
+
+$(eval $(autotools-package))
+$(eval $(host-autotools-package))