firmware: add microcode package for AMD

Use the Debian repository for sourcing the ucode files.

Current (20171205) includes support for fam17h CPUs already.

The microcodes will be updated from preinit via a common
script - that's the earliest place where we can do it.

Signed-off-by: Zoltan HERPAI <wigyori@uid0.hu>

package/firmware/amd64-microcode/Makefile

@@ -0,0 +1,45 @@
+#
+# Copyright (C) 2018 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=amd64-microcode
+PKG_VERSION:=20171205
+PKG_RELEASE:=1
+
+PKG_SOURCE:=amd64-microcode_3.$(PKG_VERSION).$(PKG_RELEASE).tar.xz
+PKG_SOURCE_URL:=http://ftp.debian.org/debian/pool/non-free/a/amd64-microcode/
+PKG_HASH:=a38bc072f535a3d3c1bf4e9e545197aa5114e979e94ef7e4a67e615df2f853a7
+PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-3.$(PKG_VERSION).$(PKG_RELEASE)
+
+PKG_LICENSE_FILE:=LICENSE.amd-ucode
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/amd64-microcode
+  SECTION:=firmware
+  CATEGORY:=Firmware
+  URL:=$(PKG_SOURCE_URL)
+  DEPENDS:=@TARGET_x86
+  TITLE:=AMD64 CPU microcode
+endef
+
+define Build/Prepare
+	rm -rf $(PKG_BUILD_DIR)
+	mkdir -p $(PKG_BUILD_DIR)
+	$(TAR) -C $(BUILD_DIR) -xJf $(DL_DIR)/$(PKG_SOURCE)
+endef
+
+define Build/Compile
+endef
+
+define Package/amd64-microcode/install
+	$(INSTALL_DIR) $(1)/lib/firmware/amd-ucode
+	$(INSTALL_DATA) $(PKG_BUILD_DIR)/*.bin $(1)/lib/firmware/amd-ucode
+endef
+
+$(eval $(call BuildPackage,amd64-microcode))