[LEDE-DEV] [PATCH 3/3] intel-microcode: create early load microcode image

[Tomasz Maciej Nowak]

Create initrd image with packed microcode. This'll allow to load it at
early boot stage. Unfortunately the package can't install files directly
to /boot directory, therefore additional installation hooks are placed
for standalone package and when building directly into target image.

Signed-off-by: Tomasz Maciej Nowak <tomek_n at o2.pl>
---
 package/firmware/intel-microcode/Makefile | 32 +++++++++++++++++++++++++------
 target/linux/x86/image/Makefile           |  6 ++++++
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/package/firmware/intel-microcode/Makefile b/package/firmware/intel-microcode/Makefile
index d2663bb901..9970f8f072 100644
--- a/package/firmware/intel-microcode/Makefile
+++ b/package/firmware/intel-microcode/Makefile
@@ -35,15 +35,35 @@ define Package/intel-microcode
 endef
 
 define Build/Compile
-	IUCODE_TOOL=$(STAGING_DIR)/../host/bin/iucode_tool $(MAKE) -C $(PKG_BUILD_DIR)
-	mkdir $(PKG_BUILD_DIR)/intel-ucode
-	$(STAGING_DIR)/../host/bin/iucode_tool -q \
-		--write-firmware=$(PKG_BUILD_DIR)/intel-ucode $(PKG_BUILD_DIR)/$(MICROCODE).bin
+	IUCODE_TOOL=$(STAGING_DIR)/../host/bin/iucode_tool \
+		$(MAKE) -C $(PKG_BUILD_DIR)
+	$(STAGING_DIR)/../host/bin/iucode_tool -q --mini-earlyfw \
+		--write-earlyfw=$(PKG_BUILD_DIR)/intel-ucode.cpio \
+		$(PKG_BUILD_DIR)/$(MICROCODE).bin
 endef
 
 define Package/intel-microcode/install
-	$(INSTALL_DIR) $(1)/lib/firmware/intel-ucode
-	$(INSTALL_DATA) $(PKG_BUILD_DIR)/intel-ucode/* $(1)/lib/firmware/intel-ucode
+	$(INSTALL_DIR) $(1)/lib/firmware
+	$(INSTALL_DATA) $(PKG_BUILD_DIR)/intel-ucode.cpio \
+		$(1)/lib/firmware/intel-ucode.img
+endef
+
+ifeq ($(CONFIG_PACKAGE_intel-microcode),m)
+define Package/intel-microcode/postinst
+#!/bin/sh
+
+mount /boot -o remount,rw,noatime
+cp -f /lib/firmware/intel-ucode.img /boot/
+mount /boot -o remount,ro,noatime
+endef
+endif
+
+define Package/intel-microcode/prerm
+#!/bin/sh
+
+mount /boot -o remount,rw,noatime
+rm /boot/intel-ucode.img
+mount /boot -o remount,ro,noatime
 endef
 
 $(eval $(call BuildPackage,intel-microcode))
diff --git a/target/linux/x86/image/Makefile b/target/linux/x86/image/Makefile
index a05f4babd9..4d6a3016d2 100644
--- a/target/linux/x86/image/Makefile
+++ b/target/linux/x86/image/Makefile
@@ -83,6 +83,9 @@ ifneq ($(CONFIG_GRUB_IMAGES),)
 		-e 's#@TIMEOUT@#$(GRUB_TIMEOUT)#g' \
 		-e 's#@ROOT@#$(GRUB_ROOT)#g' \
 		./grub.cfg > $(KDIR)/root.grub/boot/grub/grub.cfg
+    ifeq ($(CONFIG_PACKAGE_intel-microcode),y)
+	$(CP) $(STAGING_DIR)/root-x86/lib/firmware/intel-ucode.img $(KDIR)/root.grub/boot/
+    endif
 	PADDING="$(CONFIG_TARGET_IMAGES_PAD)" SIGNATURE="$(SIGNATURE)" PATH="$(TARGET_PATH)" $(SCRIPT_DIR)/gen_image_generic.sh \
 		$(BIN_DIR)/$(IMG_PREFIX)-combined-$(1).img \
 		$(CONFIG_TARGET_KERNEL_PARTSIZE) $(KDIR)/root.grub \
@@ -120,6 +123,9 @@ define Image/Build/iso
 		-e 's#@CMDLINE@#root=/dev/sr0 rootfstype=iso9660 rootwait $(strip $(call Image/cmdline/$(1)) $(BOOTOPTS) $(GRUB_CONSOLE_CMDLINE))#g' \
 		-e 's#@TIMEOUT@#$(GRUB_TIMEOUT)#g' \
 		./grub-iso.cfg > $(KDIR)/root.grub/boot/grub/grub.cfg
+  ifeq ($(CONFIG_PACKAGE_intel-microcode),y)
+	$(CP) $(STAGING_DIR)/root-x86/lib/firmware/intel-ucode.img $(KDIR)/root.grub/boot/
+  endif
 	mkisofs -R -b boot/grub/eltorito.img -no-emul-boot -boot-info-table \
 		-o $(KDIR)/root.iso $(KDIR)/root.grub $(TARGET_DIR)
 endef
-- 
2.16.3