package/intel-microcode: make target installation optional

For early microcode loading, there is no need to install the individual
microcode files to /lib/firmware - So make that optional.

Let the option default to y for backwards compatibility, and select it from
iucode-tool as the init script relies on the /lib/firmware files.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/intel-microcode/Config.in

@@ -7,3 +7,12 @@ config BR2_PACKAGE_INTEL_MICROCODE
 	  proper kernel support are required to upload the microcode.
 
 	  https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files
+
+config BR2_PACKAGE_INTEL_MICROCODE_INSTALL_TARGET
+	bool "install microcode files to /lib/firmware in target"
+	default y
+	depends on BR2_PACKAGE_INTEL_MICROCODE
+	help
+	  Select this option to have the microcode files installed to
+	  /lib/firmware/intel-ucode in the target root filesystem, in
+	  addition to the images directory.

package/intel-microcode/intel-microcode.mk

@@ -17,10 +17,14 @@ define INTEL_MICROCODE_INSTALL_IMAGES_CMDS
 		$(@D)/intel-ucode/*
 endef
 
+ifeq ($(BR2_PACKAGE_INTEL_MICROCODE_INSTALL_TARGET),y)
 define INTEL_MICROCODE_INSTALL_TARGET_CMDS
 	mkdir -p $(TARGET_DIR)/lib/firmware/intel-ucode
 	$(INSTALL) -m 0644 -t $(TARGET_DIR)/lib/firmware/intel-ucode \
 		$(@D)/intel-ucode/*
 endef
+else
+INTEL_MICROCODE_INSTALL_TARGET = NO
+endif
 
 $(eval $(generic-package))

package/iucode-tool/Config.in

@@ -2,6 +2,7 @@ config BR2_PACKAGE_IUCODE_TOOL
 	bool "iucode-tool"
 	depends on BR2_x86_64 || BR2_i386
 	select BR2_PACKAGE_INTEL_MICROCODE
+	select BR2_PACKAGE_INTEL_MICROCODE_INSTALL_TARGET
 	select BR2_PACKAGE_ARGP_STANDALONE \
 	       if BR2_TOOLCHAIN_USES_UCLIBC || BR2_TOOLCHAIN_USES_MUSL
 	help