payloads/external/LinuxBoot: Clean up

There were some issues with the current Linuxboot Makefiles.
- multithreaded compilation didn't work, because some prerequisites
  were missing
- initramfs wasn't added for x86 qemu boot.
- riscv support was incomplete

It began with separate patches, but resulted in a clean up patch, that
is hard to separate. The most important changes are the following:
- Instead of phony targets, actual files are now used as prerequisites
- riscv can now be used as target
- initramfs works now also for x86
- instead of querying the most recent version from the internet, I set a
  known working version (because I tested it) that can be customized
  and/or upgraded in the future. The reasons:
      - querying the version from the internet requires a constant
        connection to the internet even after linux kernel is already
        build (aka subsequent builds).
      - one usually wants to use a known working version, but optionally
        still have the posibillity to choose a custom one. This patch
        introduces this possibility in its most simple form.
- I removed as much ifeq statements as possible and moved that
  responsibility to Kconfig, because they tend to make the
  Makefile less readable.

Signed-off-by: Maximilian Brune <maximilian.brune@9elements.com>
Change-Id: I25e757108e0dd473969fe5a192ad0733f1fe6286
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76150
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

11 files changed, 246 insertions, 279 deletions

diff --git a/payloads/external/LinuxBoot/Kconfig b/payloads/external/LinuxBoot/Kconfig
index 4feb98b9db..24bfe3f112 100644
--- a/payloads/external/LinuxBoot/Kconfig
+++ b/payloads/external/LinuxBoot/Kconfig
@@ -19,6 +19,13 @@ config LINUXBOOT_X86
 	help
 	  X86 kernel and initramfs
 
+config LINUXBOOT_ARM
+	bool "arm64"
+	depends on ARCH_ARM
+	select PAYLOAD_FIT_SUPPORT
+	help
+	  arm kernel and initramfs
+
 config LINUXBOOT_ARM64
 	bool "arm64"
 	depends on ARCH_ARM64
@@ -26,9 +33,16 @@ config LINUXBOOT_ARM64
 	help
 	  AARCH64 kernel and initramfs
 
-config LINUXBOOT_RISCV
+config LINUXBOOT_RISCV_RV32
+	bool "RISC-V"
+	depends on ARCH_RISCV_RV32
+	select PAYLOAD_FIT_SUPPORT
+	help
+	  RISC-V kernel and initramfs
+
+config LINUXBOOT_RISCV_RV64
 	bool "RISC-V"
-	depends on ARCH_RISCV
+	depends on ARCH_RISCV_RV64
 	select PAYLOAD_FIT_SUPPORT
 	help
 	  RISC-V kernel and initramfs
@@ -41,76 +55,38 @@ config LINUXBOOT_COMPILE_KERNEL
 	bool "Compile kernel"
 	default n
 
-if LINUXBOOT_COMPILE_KERNEL
-comment "parse linux crosscompiler with: LINUXBOOT_CROSS_COMPILE"
-endif
-
 config LINUXBOOT_KERNEL_PATH
 	string "Path to kernel"
-	default "Image"
-	depends on !LINUXBOOT_COMPILE_KERNEL
-
-if LINUXBOOT_COMPILE_KERNEL
-
-choice
-	prompt "Kernel release"
-	default LINUXBOOT_KERNEL_STABLE
-	help
-	  Choose the kernel release.
-
-	  Select 'custom' if your want to define the kernel version.
-	  For more information about the current 'mainline', 'stable' or 'longterm'
-	  version, visit: https://www.kernel.org/
-
-config LINUXBOOT_KERNEL_MAINLINE
-	bool "mainline"
+	default "build/uImage" if LINUXBOOT_KERNEL_UIMAGE
+	default "build/bzImage" if LINUXBOOT_KERNEL_BZIMAGE
 	help
-	  Mainline kernel version
+	  The kernel path is either and absolute path or relative to the
+	  LinuxBoot directory
 
-config LINUXBOOT_KERNEL_STABLE
-	bool "stable"
-	help
-	  Stable kernel version
-
-config LINUXBOOT_KERNEL_LONGTERM
-	bool "longterm"
-	help
-	  Longterm (LTS) kernel version
+if LINUXBOOT_COMPILE_KERNEL
 
-config LINUXBOOT_KERNEL_CUSTOM
-	bool "custom"
+config LINUXBOOT_CROSS_COMPILE
+	string "cross compiler"
+	default "" # e.g. "aarch64-linux-gnu-"
 	help
-	  Custom kernel version
+	  Choose a custom cross compiler toolchain to use.
+	  It can be useful if you don't want to use the coreboot toolchain
+	  or experience problems using it.
 
-endchoice
-
-config LINUXBOOT_KERNEL_CUSTOM_VERSION
+config LINUXBOOT_KERNEL_VERSION
 	string "kernel version"
-	default ""
-	depends on LINUXBOOT_KERNEL_CUSTOM
+	default "6.3"
 	help
 	  Choose the Linux kernel version number. (x.x.x)
 	  Release candidate kernels (rc) are currently are not supported.
 
-choice
-	prompt "Kernel configuration"
-	default LINUXBOOT_KERNEL_ARCH_DEFAULT_CONFIG
-
-config LINUXBOOT_KERNEL_ARCH_DEFAULT_CONFIG
-	bool "Default architecture configuration"
-	help
-	  This option will use the default configuration for the
-	  selected architecture.
-
-config LINUXBOOT_KERNEL_CUSTOM_CONFIG
-	bool "Custom (def)config file"
-
-endchoice
-
 config LINUXBOOT_KERNEL_CONFIGFILE
 	string "Config file path"
-	default "defconfig"
-	depends on LINUXBOOT_KERNEL_CUSTOM_CONFIG
+	default "i386/defconfig"     if LINUXBOOT_X86
+	default "x86_64/defconfig"   if LINUXBOOT_X86_64
+	default "arm64/defconfig"    if LINUXBOOT_ARM64
+	default "riscv/defconfig-32" if LINUXBOOT_RISCV_RV32
+	default "riscv/defconfig-64" if LINUXBOOT_RISCV_RV64
 	help
 	  Path to the kernel configuration file.
 
@@ -119,7 +95,7 @@ config LINUXBOOT_KERNEL_CONFIGFILE
 choice
 	prompt "Kernel binary format"
 	default LINUXBOOT_KERNEL_BZIMAGE if LINUXBOOT_X86 || LINUXBOOT_X86_64
-	default LINUXBOOT_KERNEL_UIMAGE if LINUXBOOT_ARM64 || LINUXBOOT_RISCV
+	default LINUXBOOT_KERNEL_UIMAGE if LINUXBOOT_ARM64 || LINUXBOOT_RISCV_RV32 || LINUXBOOT_RISCV_RV64
 
 config LINUXBOOT_KERNEL_BZIMAGE
 	bool "bzImage"
@@ -127,14 +103,14 @@ config LINUXBOOT_KERNEL_BZIMAGE
 
 config LINUXBOOT_KERNEL_UIMAGE
 	bool "uImage"
-	depends on LINUXBOOT_ARM64 || LINUXBOOT_RISCV
+	depends on LINUXBOOT_ARM64 || LINUXBOOT_RISCV_RV32 || LINUXBOOT_RISCV_RV64
 
 endchoice
 
-config LINUXBOOT_DTB_FILE
+config LINUXBOOT_DTS_FILE
 	string "Compiled devicetree file"
-	depends on LINUXBOOT_ARM64 || LINUXBOOT_RISCV
-	default ""
+	depends on LINUXBOOT_ARM64 || LINUXBOOT_RISCV_RV32 || LINUXBOOT_RISCV_RV64
+	default "empty.dts"
 
 endif #LINUXBOOT_COMPILE_KERNEL
 
@@ -145,9 +121,7 @@ config LINUX_COMMAND_LINE
 	  Add your own kernel command-line arguments.
 
 config PAYLOAD_FILE
-	default "payloads/external/LinuxBoot/linuxboot/bzImage" if LINUXBOOT_COMPILE_KERNEL && ( LINUXBOOT_X86 || LINUXBOOT_X86_64 )
-	default "payloads/external/LinuxBoot/linuxboot/uImage" if LINUXBOOT_COMPILE_KERNEL && (LINUXBOOT_ARM64 || LINUXBOOT_RISCV)
-	default LINUXBOOT_KERNEL_PATH if !LINUXBOOT_COMPILE_KERNEL
+	default "payloads/external/LinuxBoot/build/Image"
 
 comment "Linux initramfs"
 
@@ -157,16 +131,17 @@ config LINUXBOOT_BUILD_INITRAMFS
 
 config LINUXBOOT_INITRAMFS_PATH
 	string "Path to initramfs"
-	depends on !LINUXBOOT_BUILD_INITRAMFS
+	default "build/initramfs_u-root.cpio" if LINUXBOOT_UROOT
 
 if LINUXBOOT_BUILD_INITRAMFS
 
 choice
-	prompt "Payload Mode"
+	prompt "Initramfs"
 	default LINUXBOOT_UROOT
 
 config LINUXBOOT_UROOT
 	bool "u-root"
+	depends on !LINUXBOOT_RISCV_RV32 # not supported by u-root
 	help
 	  Enable u-root linuxboot mode.
 	  See http://u-root.tk/ for more information.
@@ -345,11 +320,6 @@ config LINUXBOOT_INITRAMFS_COMPRESSION_XZ
 
 endchoice
 
-config LINUX_INITRD
-	string
-	default "payloads/external/LinuxBoot/linuxboot/initramfs_u-root.cpio" if LINUXBOOT_UROOT
-	default LINUXBOOT_INITRAMFS_PATH if !LINUXBOOT_BUILD_INITRAMFS
-
 config LINUXBOOT_INITRAMFS_SUFFIX
 	string
 	default "" if LINUXBOOT_INITRAMFS_COMPRESSION_NONE
diff --git a/payloads/external/LinuxBoot/Makefile b/payloads/external/LinuxBoot/Makefile
index cd9f7eaa0e..d12d323f5e 100644
--- a/payloads/external/LinuxBoot/Makefile
+++ b/payloads/external/LinuxBoot/Makefile
@@ -1,62 +1,51 @@
 ## SPDX-License-Identifier: GPL-2.0-only
 
-project_dir=linuxboot
-
 unexport $(COREBOOT_EXPORTS)
 
-all: linuxboot
+DTC ?= dtc
 
-u-root:
-	$(MAKE) -f targets/u-root.mk
+LINUX_ARCH-$(CONFIG_LINUXBOOT_X86_64)     = x86_64
+LINUX_ARCH-$(CONFIG_LINUXBOOT_X86)        = i386
+LINUX_ARCH-$(CONFIG_LINUXBOOT_ARM64)      = arm64
+LINUX_ARCH-$(CONFIG_LINUXBOOT_RISCV_RV32) = riscv
+LINUX_ARCH-$(CONFIG_LINUXBOOT_RISCV_RV64) = riscv
 
-ifeq ($(CONFIG_LINUXBOOT_BUILD_INITRAMFS),y)
-ifeq ($(CONFIG_LINUXBOOT_UROOT),y)
-initramfs: u-root
-endif
-else
-ifneq ($(CONFIG_LINUXBOOT_INITRAMFS),)
-initramfs:
-	if [[ ! -f "$(top)/$(CONFIG_LINUXBOOT_INITRAMFS)" ]]; then \
-	echo "<< Linux initramfs '$(CONFIG_LINUXBOOT_INITRAMFS)' is missing. >>"; \
-	exit 1; \
-	fi
-endif
-endif
+build/Image: $(CONFIG_LINUXBOOT_KERNEL_PATH)
+	ln -s -r $< $@
+
+include targets/linux.mk targets/u-root.mk
 
-initramfs_compressed: initramfs
+build/initramfs: $(CONFIG_LINUXBOOT_INITRAMFS_PATH)
 ifeq ($(CONFIG_LINUXBOOT_INITRAMFS_COMPRESSION_XZ),y)
-	xz --keep --force --check=crc32 --lzma2=dict=1MiB $(top)/$(CONFIG_LINUXBOOT_INITRAMFS)
+	xz --keep --force --check=crc32 --lzma2=dict=1MiB $(CONFIG_LINUXBOOT_INITRAMFS_PATH)
 endif
+	cp $(CONFIG_LINUXBOOT_INITRAMFS_PATH)$(CONFIG_LINUXBOOT_INITRAMFS_SUFFIX) $@
 
-ifeq ($(CONFIG_LINUXBOOT_COMPILE_KERNEL),y)
-ifeq ($(CONFIG_LINUXBOOT_ARCH),arm64)
-kernel: initramfs
-	if [[ ! -f "$(top)/$(CONFIG_LINUXBOOT_DTB_FILE)" ]]; then \
-	echo "<< Linux kernel devicetree is missing. >>"; \
-	exit 1; \
-	fi
-	$(MAKE) -f targets/linux.mk
-else
-kernel:
-	$(MAKE) -f targets/linux.mk
-endif
-else
-kernel:
-	if [[ ! -f "$(top)/$(CONFIG_LINUXBOOT_KERNEL)" ]]; then \
-	echo "<< Linux kernel '$(CONFIG_LINUXBOOT_KERNEL)' is missing. >>"; \
-	exit 1; \
-	fi
-endif
+ifeq ($(CONFIG_LINUXBOOT_KERNEL_BZIMAGE),y)
+
+build/bzImage: $(kernel_dir)/arch/x86/boot/bzImage | build
+	cp $< $@
+
+else ifeq ($(CONFIG_LINUXBOOT_KERNEL_UIMAGE),y)
+
+build/target.dtb: $(CONFIG_LINUXBOOT_DTS_FILE)
+	$(DTC) -o $@ $<
+
+build/uImage: build/vmlinux.bin.lzma build/initramfs build/target.dtb $(LINUX_ARCH-y)/kernel_fdt_lzma.its | build
+	mkimage -f $(LINUX_ARCH-y)/kernel_fdt_lzma.its $@
+
+endif # CONFIG_LINUXBOOT_KERNEL_BZIMAGE
 
-linuxboot: kernel initramfs_compressed
+build:
+	mkdir build
 
 clean:
-	rm -rf $(project_dir)/kernel*
-	rm -f $(project_dir)/u-root
-	rm -f $(project_dir)/initramfs*
-	rm -f $(project_dir)/bzImage
+	rm -rf build/kernel*
+	rm -f  build/u-root
+	rm -f  build/initramfs*
+	rm -f  build/bzImage
 
 distclean:
-	rm -rf $(project_dir)
+	rm -rf build
 
-.PHONY: linuxboot kernel initramfs_compressed initramfs u-root clean distclean
+.PHONY: linuxboot clean distclean
diff --git a/payloads/external/LinuxBoot/arm64/kernel_fdt_lzma.its b/payloads/external/LinuxBoot/arm64/kernel_fdt_lzma.its
index 3087e69a74..46c43ac9dc 100644
--- a/payloads/external/LinuxBoot/arm64/kernel_fdt_lzma.its
+++ b/payloads/external/LinuxBoot/arm64/kernel_fdt_lzma.its
@@ -11,7 +11,7 @@
 	images {
 		kernel {
 			description = "Vanilla Linux kernel";
-			data = /incbin/("vmlinux.bin.lzma");
+			data = /incbin/("../build/vmlinux.bin.lzma");
 			type = "kernel";
 			arch = "arm64";
 			os = "linux";
@@ -30,7 +30,7 @@
 		};
 		fdt-1 {
 			description = "Flattened Device Tree blob";
-			data = /incbin/("target.dtb");
+			data = /incbin/("../build/target.dtb");
 			type = "flat_dt";
 			arch = "arm64";
 			compression = "none";
@@ -46,7 +46,7 @@
 		};
 		ramdisk-1 {
 			description = "Compressed Initramfs";
-			data = /incbin/("initramfs");
+			data = /incbin/("../build/initramfs");
 			type = "ramdisk";
 			arch = "arm64";
 			os = "linux";
@@ -65,6 +65,7 @@
 	configurations {
 		default = "conf-1";
 		conf-1 {
+			compatible = "linuxboot";
 			description = "Boot Linux kernel with FDT blob";
 			kernel = "kernel";
 			fdt = "fdt-1";
diff --git a/payloads/external/LinuxBoot/empty.dts b/payloads/external/LinuxBoot/empty.dts
new file mode 100644
index 0000000000..e160dad6a6
--- /dev/null
+++ b/payloads/external/LinuxBoot/empty.dts
@@ -0,0 +1,4 @@
+/dts-v1/;
+
+/ {
+};
diff --git a/payloads/external/LinuxBoot/x86/defconfig b/payloads/external/LinuxBoot/i386/defconfig
index 6c20c145cd..6c20c145cd 100644
--- a/payloads/external/LinuxBoot/x86/defconfig
+++ b/payloads/external/LinuxBoot/i386/defconfig
diff --git a/payloads/external/LinuxBoot/riscv/defconfig-32 b/payloads/external/LinuxBoot/riscv/defconfig-32
new file mode 100644
index 0000000000..f6af0f708d
--- /dev/null
+++ b/payloads/external/LinuxBoot/riscv/defconfig-32
@@ -0,0 +1,4 @@
+CONFIG_ARCH_RV32I=y
+CONFIG_32BIT=y
+# CONFIG_PORTABLE is not set
+CONFIG_NONPORTABLE=y
diff --git a/payloads/external/LinuxBoot/riscv/defconfig-64 b/payloads/external/LinuxBoot/riscv/defconfig-64
new file mode 100644
index 0000000000..313edc554d
--- /dev/null
+++ b/payloads/external/LinuxBoot/riscv/defconfig-64
@@ -0,0 +1,2 @@
+CONFIG_ARCH_RV64I=y
+CONFIG_64BIT=y
diff --git a/payloads/external/LinuxBoot/riscv/kernel_fdt_lzma.its b/payloads/external/LinuxBoot/riscv/kernel_fdt_lzma.its
new file mode 100644
index 0000000000..6cbe484910
--- /dev/null
+++ b/payloads/external/LinuxBoot/riscv/kernel_fdt_lzma.its
@@ -0,0 +1,74 @@
+/*
+ * Simple U-Boot uImage source file containing a single kernel and FDT blob
+ */
+
+/dts-v1/;
+
+/ {
+	description = "Simple image with single Linux kernel and FDT blob";
+	#address-cells = <1>;
+
+	images {
+		kernel {
+			description = "Vanilla Linux kernel";
+			data = /incbin/("../build/vmlinux.bin.lzma");
+			type = "kernel";
+			arch = "riscv64";
+			os = "linux";
+			compression = "lzma";
+			load = <0x80000>;
+			entry = <0x80000>;
+			hash-1 {
+				algo = "crc32";
+			};
+			hash-2 {
+				algo = "sha1";
+			};
+			hash-3 {
+				algo = "sha256";
+			};
+		};
+		fdt-1 {
+			description = "Flattened Device Tree blob";
+			data = /incbin/("../build/target.dtb");
+			type = "flat_dt";
+			arch = "riscv64";
+			compression = "none";
+			hash-1 {
+				algo = "crc32";
+			};
+			hash-2 {
+				algo = "sha1";
+			};
+			hash-3 {
+				algo = "sha256";
+			};
+		};
+		ramdisk-1 {
+			description = "Compressed Initramfs";
+			data = /incbin/("../build/initramfs");
+			type = "ramdisk";
+			arch = "riscv64";
+			os = "linux";
+			compression = "none";
+			load = <00000000>;
+			entry = <00000000>;
+			hash-1 {
+				algo = "sha1";
+			};
+			hash-2 {
+				algo = "sha256";
+			};
+		};
+	};
+
+	configurations {
+		default = "conf-1";
+		conf-1 {
+			description = "Boot Linux kernel with FDT blob";
+			kernel = "kernel";
+			fdt = "fdt-1";
+			ramdisk = "ramdisk-1";
+		};
+	};
+};
diff --git a/payloads/external/LinuxBoot/targets/linux.mk b/payloads/external/LinuxBoot/targets/linux.mk
index 12f66f7049..4156e1ee74 100644
--- a/payloads/external/LinuxBoot/targets/linux.mk
+++ b/payloads/external/LinuxBoot/targets/linux.mk
@@ -1,41 +1,20 @@
 ## SPDX-License-Identifier: GPL-2.0-only
 
-SHELL := /bin/bash
+SHELL := /bin/sh
 
-ARCH-$(CONFIG_LINUXBOOT_X86_64)=x86_64
-ARCH-$(CONFIG_LINUXBOOT_X86)=x86
-ARCH-$(CONFIG_LINUXBOOT_ARM64)=arm64
-
-TAG-$(CONFIG_LINUXBOOT_KERNEL_MAINLINE)=mainline
-TAG-$(CONFIG_LINUXBOOT_KERNEL_STABLE)=stable
-TAG-$(CONFIG_LINUXBOOT_KERNEL_LONGTERM)=longterm
-
-pwd:=$(shell pwd)
-top:=../../..
-project_dir=linuxboot
-tarball_dir:=$(project_dir)/tarball
-decompress_flag=.done
-
-OBJCOPY:=$(LINUXBOOT_CROSS_COMPILE)objcopy
+OBJCOPY:=$(CONFIG_LINUXBOOT_CROSS_COMPILE)objcopy
 KERNEL_MAKE_FLAGS = \
-	ARCH=$(ARCH-y) \
+	CROSS_COMPILE=$(CONFIG_LINUXBOOT_CROSS_COMPILE) \
+	ARCH=$(LINUX_ARCH-y) \
 	KBUILD_BUILD_USER="coreboot" \
 	KBUILD_BUILD_HOST="reproducible" \
 	KBUILD_BUILD_TIMESTAMP="$(shell perl -e 'print scalar gmtime($(SOURCE_DATE_EPOCH))')" \
 	KBUILD_BUILD_VERSION="0"
 
-ifeq ($(CONFIG_LINUXBOOT_KERNEL_CUSTOM),y)
-	kernel_version:=$(CONFIG_LINUXBOOT_KERNEL_CUSTOM_VERSION)
-else
-	kernel_version:=$(shell curl -sS -k https://www.kernel.org/feeds/kdist.xml | \
-		sed -n -e 's@.*<guid isPermaLink="false">\(.*\)</guid>.*@\1@p' | \
-		awk -F ',' '/$(TAG-y)/{ print $$3 }' | \
-		head -n 1)
-endif
-
-kernel_dir=$(project_dir)/kernel-$(subst .,_,$(kernel_version))
-kernel_tarball=linux-$(kernel_version).tar
-kernel_mirror=https://mirrors.edge.kernel.org/pub/linux/kernel
+kernel_version = $(CONFIG_LINUXBOOT_KERNEL_VERSION)
+kernel_dir = build/kernel-$(subst .,_,$(kernel_version))
+kernel_tarball = linux-$(kernel_version).tar
+kernel_mirror  = https://mirrors.edge.kernel.org/pub/linux/kernel
 
 ifeq ($(findstring x2.6.,x$(kernel_version)),x2.6.)
 kernel_mirror_path := $(kernel_mirror)/v2.6
@@ -49,81 +28,35 @@ else ifeq ($(findstring x6.,x$(kernel_version)),x6.)
 kernel_mirror_path := $(kernel_mirror)/v6.x
 endif
 
-all: kernel
-
-lookup:
-ifeq ($(kernel_version),)
-	$(error kernel version lookup failed for $(TAG-y) release)
-endif
-	@echo "    WWW        Kernel [$(TAG-y)] $(kernel_version)"
-
-fetch:
-ifneq ($(shell [[ -d "$(kernel_dir)" && -f "$(kernel_dir)/$(decompress_flag)" ]];echo $$?),0)
-	mkdir -p $(tarball_dir)
-	if [[ ! -f $(tarball_dir)/$(kernel_tarball).xz && ! -f $(tarball_dir)/$(kernel_tarball).xz ]]; then \
-	echo "    WWW        $(kernel_tarball).xz"; \
-	cd $(tarball_dir); \
-	curl -OLSs "$(kernel_mirror_path)/$(kernel_tarball).xz"; \
-	cd $(pwd); \
-	fi
-endif
+build/$(kernel_tarball).xz:
+	echo "    Test $(kernel_version)"
+	echo "    WWW        $(kernel_mirror_path)/$(kernel_tarball).xz";
+	curl -OLSs --output-dir build "$(kernel_mirror_path)/$(kernel_tarball).xz";
 
-unpack: fetch
-	if [[ -d "$(kernel_dir)" && ! -f "$(kernel_dir)/$(decompress_flag)" ]]; then \
-	rm -rf $(kernel_dir); \
-	fi
-	if [[ ! -d "$(kernel_dir)" ]]; then \
-	mkdir $(kernel_dir); \
-	echo "    XZ         $(kernel_tarball).xz"; \
-	tar xJf $(tarball_dir)/$(kernel_tarball).xz --strip 1 -C $(kernel_dir); \
-	fi
-	touch $(kernel_dir)/$(decompress_flag)
+$(kernel_dir): build/$(kernel_tarball).xz
+	echo "    XZ         $(kernel_tarball).xz";
+	mkdir $(kernel_dir);
+	tar xJf build/$(kernel_tarball).xz --strip 1 -C $(kernel_dir);
 
-$(kernel_dir)/.config: unpack
+$(kernel_dir)/.config: $(CONFIG_LINUXBOOT_KERNEL_CONFIGFILE) | $(kernel_dir)
 	@echo "    CONFIG     Linux $(kernel_version)"
-ifeq ($(CONFIG_LINUXBOOT_KERNEL_CUSTOM_CONFIG),y)
 	cp $(CONFIG_LINUXBOOT_KERNEL_CONFIGFILE) $(kernel_dir)/.config
-else
-	cp $(ARCH-y)/defconfig $(kernel_dir)/.config
-endif
 	$(MAKE) -C $(kernel_dir) $(KERNEL_MAKE_FLAGS) olddefconfig
 
-build: $(kernel_dir)/.config
+$(kernel_dir)/vmlinux : $(kernel_dir)/.config | $(kernel_dir)
 	@echo "    MAKE       Linux $(kernel_version)"
-ifeq ($(CONFIG_LINUXBOOT_KERNEL_BZIMAGE),y)
-	$(MAKE) -C $(kernel_dir) $(KERNEL_MAKE_FLAGS) CROSS_COMPILE=$(LINUXBOOT_CROSS_COMPILE) bzImage
-else
-ifeq ($(CONFIG_LINUXBOOT_KERNEL_UIMAGE),y)
-	$(MAKE) -C $(kernel_dir) $(KERNEL_MAKE_FLAGS) CROSS_COMPILE=$(LINUXBOOT_CROSS_COMPILE) vmlinux
-endif
-endif
+	echo "$(MAKE) -j 4 -C $(kernel_dir) $(KERNEL_MAKE_FLAGS) vmlinux"
+	$(MAKE) -j 4 -C $(kernel_dir) $(KERNEL_MAKE_FLAGS) vmlinux
 
-ifeq ($(CONFIG_LINUXBOOT_KERNEL_BZIMAGE),y)
-$(top)/$(CONFIG_LINUXBOOT_KERNEL): build
-	@echo "    CP         bzImage"
-	cp $(kernel_dir)/arch/x86/boot/bzImage $@
-else
-ifeq ($(CONFIG_LINUXBOOT_KERNEL_UIMAGE),y)
-$(project_dir)/target.dtb: $(top)/$(CONFIG_LINUXBOOT_DTB_FILE)
-	cp $< $@
-$(project_dir)/vmlinux.bin: $(kernel_dir)/vmlinux
+build/vmlinux.bin: $(kernel_dir)/vmlinux | build
 	$(OBJCOPY) -O binary $< $@
-$(project_dir)/vmlinux.bin.lzma: $(project_dir)/vmlinux.bin
+
+build/vmlinux.bin.lzma: build/vmlinux.bin
 	xz -c -k -f --format=lzma --lzma1=dict=1MiB,lc=3,lp=0,pb=3 $< > $@
-$(top)/$(CONFIG_LINUXBOOT_KERNEL): build $(project_dir)/vmlinux.bin.lzma $(project_dir)/target.dtb
-	cp $(project_dir)/../arm64/kernel_fdt_lzma.its $(project_dir)
-	cp $(top)/$(CONFIG_LINUXBOOT_INITRAMFS)$(CONFIG_LINUXBOOT_INITRAMFS_SUFFIX) $(project_dir)/initramfs
-	mkimage -f $(project_dir)/kernel_fdt_lzma.its $@
-else
-	$(error Kernel image format not found)
-	exit 1
-endif
-endif
 
-ifneq ($(TAG-y),)
-kernel: lookup $(top)/$(CONFIG_LINUXBOOT_KERNEL)
-else
-kernel: $(top)/$(CONFIG_LINUXBOOT_KERNEL)
-endif
+$(kernel_dir)/arch/x86/boot/bzImage: $(kernel_dir)/.config
+	@echo "    MAKE       Linux $(kernel_version)"
+	echo "$(MAKE) -C $(kernel_dir) $(KERNEL_MAKE_FLAGS) bzImage"
+	$(MAKE) -C $(kernel_dir) $(KERNEL_MAKE_FLAGS) bzImage
 
-.PHONY: all kernel build unpack fetch check
+.PHONY: kernel
diff --git a/payloads/external/LinuxBoot/targets/u-root.mk b/payloads/external/LinuxBoot/targets/u-root.mk
index e673aabf11..fff79df0a1 100644
--- a/payloads/external/LinuxBoot/targets/u-root.mk
+++ b/payloads/external/LinuxBoot/targets/u-root.mk
@@ -1,29 +1,26 @@
 ## SPDX-License-Identifier: GPL-2.0-only
 
-project_dir=$(shell pwd)/linuxboot
-go_path_dir=$(project_dir)/go
-uroot_bin=$(project_dir)/u-root
-uroot_package=github.com/u-root/u-root
-
-ARCH-$(CONFIG_LIBUXBOOT_X86_64)=amd64
-ARCH-$(CONFIG_LINUXBOOT_X86)=i386
-ARCH-$(CONFIG_LINUXBOOT_ARM64)=arm64
-
-go_version=$(shell go version | sed -nr 's/.*go([0-9]+\.[0-9]+.?[0-9]?).*/\1/p' )
-go_version_major=$(shell echo $(go_version) |  sed -nr 's/^([0-9]+)\.([0-9]+)\.?([0-9]*)$$/\1/p')
-go_version_minor=$(shell echo $(go_version) |  sed -nr 's/^([0-9]+)\.([0-9]+)\.?([0-9]*)$$/\2/p')
-
-uroot_args+=-build=$(CONFIG_LINUXBOOT_UROOT_FORMAT)
-uroot_args+=-initcmd $(CONFIG_LINUXBOOT_UROOT_INITCMD)
-uroot_args+=-uinitcmd=$(CONFIG_LINUXBOOT_UROOT_UINITCMD)
-uroot_args+=-defaultsh $(CONFIG_LINUXBOOT_UROOT_SHELL)
+uroot_package = github.com/u-root/u-root
+uroot_build = build/go/src/$(uroot_package)
+
+UROOT_ARCH-$(CONFIG_LIBUXBOOT_X86_64)      = amd64
+UROOT_ARCH-$(CONFIG_LINUXBOOT_X86)         = 386
+UROOT_ARCH-$(CONFIG_LINUXBOOT_ARM64)       = arm64
+UROOT_ARCH-$(CONFIG_LINUXBOOT_RISCV_RV64)  = riscv64
+
+go_version = $(shell go version | sed -nr 's/.*go([0-9]+\.[0-9]+.?[0-9]?).*/\1/p' )
+go_version_major = $(shell echo $(go_version) |  sed -nr 's/^([0-9]+)\.([0-9]+)\.?([0-9]*)$$/\1/p')
+go_version_minor = $(shell echo $(go_version) |  sed -nr 's/^([0-9]+)\.([0-9]+)\.?([0-9]*)$$/\2/p')
+
+uroot_args += -build=$(CONFIG_LINUXBOOT_UROOT_FORMAT)
+uroot_args += -initcmd $(CONFIG_LINUXBOOT_UROOT_INITCMD)
+uroot_args += -uinitcmd=$(CONFIG_LINUXBOOT_UROOT_UINITCMD)
+uroot_args += -defaultsh $(CONFIG_LINUXBOOT_UROOT_SHELL)
 ifneq (CONFIG_LINUXBOOT_UROOT_FILES,)
-uroot_args+=$(foreach file,$(CONFIG_LINUXBOOT_UROOT_FILES),-files $(PWD)/$(file))
+uroot_args += $(foreach file,$(CONFIG_LINUXBOOT_UROOT_FILES),-files $(PWD)/$(file))
 endif
 
-uroot_cmds=$(CONFIG_LINUXBOOT_UROOT_COMMANDS)
-
-all: u-root
+uroot_cmds = $(CONFIG_LINUXBOOT_UROOT_COMMANDS)
 
 version:
 ifeq ("$(go_version)","")
@@ -38,27 +35,16 @@ ifeq ($(shell if [ $(go_version_minor) -lt 9 ]; then echo y; fi),y)
 endif
 endif
 
-get: version
-	if [ -d "$(go_path_dir)/src/$(uroot_package)" ]; then \
-	git -C $(go_path_dir)/src/$(uroot_package) checkout --quiet main; \
-	git -C $(go_path_dir)/src/$(uroot_package) pull || \
-	echo -e "\n<<Pulling u-root package from GitHub failed>>\n"; \
-	else \
-	git clone https://${uroot_package} ${go_path_dir}/src/${uroot_package} || \
-	(echo -e "\n<<Failed to clone u-root package. Please check your internet access>>\n" && \
-	exit 1); \
-	fi
-
-checkout: get
-	git -C $(go_path_dir)/src/$(uroot_package) checkout --quiet $(CONFIG_LINUXBOOT_UROOT_VERSION)
-
-build: checkout
-	cd ${go_path_dir}/src/${uroot_package}; \
-	go build -o ${uroot_bin} .
+$(uroot_build):
+	git clone https://$(uroot_package) $(uroot_build)
+	git -C $(uroot_build) checkout --quiet $(CONFIG_LINUXBOOT_UROOT_VERSION)
 
-u-root: build
-	GOARCH=$(ARCH-y) $(uroot_bin) \
-	-uroot-source ${go_path_dir}/src/${uroot_package} \
-	$(uroot_args) -o $(project_dir)/initramfs_u-root.cpio $(uroot_cmds)
+$(uroot_build)/u-root: $(uroot_build)
+	cd $(uroot_build); \
+	go build -o u-root .
 
-.PHONY: all u-root build checkout get version
+#$(CONFIG_LINUXBOOT_INITRAMFS_PATH)
+build/initramfs_u-root.cpio: $(uroot_build)/u-root
+	GOARCH=$(UROOT_ARCH-y) $(uroot_build)/u-root \
+	-uroot-source $(uroot_build) \
+	$(uroot_args) -o build/initramfs_u-root.cpio $(uroot_cmds)
diff --git a/payloads/external/Makefile.inc b/payloads/external/Makefile.inc
index 33df6fb46e..4d3799de89 100644
--- a/payloads/external/Makefile.inc
+++ b/payloads/external/Makefile.inc
@@ -26,8 +26,8 @@ ifneq ($(strip $(call strip_quotes,$(CONFIG_LINUX_COMMAND_LINE))),)
 endif
 ifneq ($(strip $(call strip_quotes,$(CONFIG_LINUX_INITRD))),)
 ifneq ($(CONFIG_LINUXBOOT_ARM64),y)
-      ADDITIONAL_PAYLOAD_CONFIG+=-I $(CONFIG_LINUX_INITRD)$(CONFIG_LINUXBOOT_INITRAMFS_SUFFIX)
-      prebuilt-files += $(strip $(call strip_quotes,$(CONFIG_LINUX_INITRD)))
+      ADDITIONAL_PAYLOAD_CONFIG+=-I $(CONFIG_LINUX_INITRD)$(CONFIG_LINUXBOOT_INITRAMFS)$(CONFIG_LINUXBOOT_INITRAMFS_SUFFIX)
+      prebuilt-files += $(strip $(call strip_quotes,$(CONFIG_LINUX_INITRD)$(CONFIG_LINUXBOOT_INITRAMFS)))
 endif
 endif
 endif
@@ -367,41 +367,45 @@ payloads/external/iPXE/ipxe/ipxe.rom ipxe: $(DOTCONFIG) $(PXE_CONFIG_SCRIPT)
 	MFLAGS= MAKEFLAGS=
 
 # LinuxBoot
+LINUXBOOT_CROSS_COMPILE_ARCH-$(CONFIG_LINUXBOOT_X86)        = x86_32
+LINUXBOOT_CROSS_COMPILE_ARCH-$(CONFIG_LINUXBOOT_X86_64)     = x86_64
+LINUXBOOT_CROSS_COMPILE_ARCH-$(CONFIG_LINUXBOOT_ARM)        = arm
+LINUXBOOT_CROSS_COMPILE_ARCH-$(CONFIG_LINUXBOOT_ARM64)      = arm64
+LINUXBOOT_CROSS_COMPILE_ARCH-$(CONFIG_LINUXBOOT_RISCV_RV32) = riscv
+LINUXBOOT_CROSS_COMPILE_ARCH-$(CONFIG_LINUXBOOT_RISCV_RV64) = riscv
+ifeq ($(CONFIG_LINUXBOOT_CROSS_COMPILE),)
+	CONFIG_LINUXBOOT_CROSS_COMPILE=$(CROSS_COMPILE_$(LINUXBOOT_CROSS_COMPILE_ARCH-y))
+endif
 .PHONY: linuxboot
-linuxboot:
+payloads/external/LinuxBoot/build/Image linuxboot:
 	$(MAKE) -C payloads/external/LinuxBoot \
 		CPUS=$(CPUS) \
 		CONFIG_LINUXBOOT_X86_64=$(CONFIG_LINUXBOOT_X86_64) \
 		CONFIG_LINUXBOOT_X86=$(CONFIG_LINUXBOOT_X86) \
+		CONFIG_LINUXBOOT_ARM=$(CONFIG_LINUXBOOT_ARM) \
 		CONFIG_LINUXBOOT_ARM64=$(CONFIG_LINUXBOOT_ARM64) \
-		CONFIG_LINUXBOOT_KERNEL=$(CONFIG_PAYLOAD_FILE) \
-		CONFIG_LINUXBOOT_INITRAMFS=$(CONFIG_LINUX_INITRD) \
+		CONFIG_LINUXBOOT_RISCV_RV32=$(CONFIG_LINUXBOOT_RISCV_RV32) \
+		CONFIG_LINUXBOOT_RISCV_RV64=$(CONFIG_LINUXBOOT_RISCV_RV64) \
+		CONFIG_LINUXBOOT_CROSS_COMPILE=$(CONFIG_LINUXBOOT_CROSS_COMPILE) \
+		CONFIG_LINUXBOOT_BUILD_INITRAMFS=$(CONFIG_LINUXBOOT_BUILD_INITRAMFS) \
+		CONFIG_LINUXBOOT_INITRAMFS_PATH=$(CONFIG_LINUXBOOT_INITRAMFS_PATH) \
 		CONFIG_LINUXBOOT_INITRAMFS_SUFFIX=$(CONFIG_LINUXBOOT_INITRAMFS_SUFFIX) \
+		CONFIG_LINUXBOOT_INITRAMFS_COMPRESSION_XZ=$(CONFIG_LINUXBOOT_INITRAMFS_COMPRESSION_XZ) \
 		CONFIG_LINUXBOOT_COMPILE_KERNEL=$(CONFIG_LINUXBOOT_COMPILE_KERNEL) \
-		CONFIG_LINUXBOOT_BUILD_INITRAMFS=$(CONFIG_LINUXBOOT_BUILD_INITRAMFS) \
-		CONFIG_LINUXBOOT_KERNEL_MAINLINE=$(CONFIG_LINUXBOOT_KERNEL_MAINLINE) \
-		CONFIG_LINUXBOOT_KERNEL_STABLE=$(CONFIG_LINUXBOOT_KERNEL_STABLE) \
-		CONFIG_LINUXBOOT_KERNEL_LONGTERM=$(CONFIG_LINUXBOOT_KERNEL_LONGTERM) \
-		CONFIG_LINUXBOOT_KERNEL_CUSTOM=$(CONFIG_LINUXBOOT_KERNEL_CUSTOM) \
-		CONFIG_LINUXBOOT_KERNEL_CUSTOM_VERSION=$(CONFIG_LINUXBOOT_KERNEL_CUSTOM_VERSION) \
-		CONFIG_LINUXBOOT_KERNEL_CUSTOM_CONFIG=$(CONFIG_LINUXBOOT_KERNEL_CUSTOM_CONFIG) \
+		CONFIG_LINUXBOOT_KERNEL_PATH=$(CONFIG_LINUXBOOT_KERNEL_PATH) \
+		CONFIG_LINUXBOOT_KERNEL_VERSION=$(CONFIG_LINUXBOOT_KERNEL_VERSION) \
 		CONFIG_LINUXBOOT_KERNEL_BZIMAGE=$(CONFIG_LINUXBOOT_KERNEL_BZIMAGE) \
 		CONFIG_LINUXBOOT_KERNEL_UIMAGE=$(CONFIG_LINUXBOOT_KERNEL_UIMAGE) \
 		CONFIG_LINUXBOOT_KERNEL_CONFIGFILE=$(CONFIG_LINUXBOOT_KERNEL_CONFIGFILE) \
-		CONFIG_LINUXBOOT_INITRAMFS_COMPRESSION_XZ=$(CONFIG_LINUXBOOT_INITRAMFS_COMPRESSION_XZ) \
 		CONFIG_LINUXBOOT_UROOT=$(CONFIG_LINUXBOOT_UROOT) \
 		CONFIG_LINUXBOOT_UROOT_VERSION=$(CONFIG_LINUXBOOT_UROOT_VERSION) \
 		CONFIG_LINUXBOOT_UROOT_FORMAT=$(CONFIG_LINUXBOOT_UROOT_FORMAT) \
 		CONFIG_LINUXBOOT_UROOT_INITCMD=$(CONFIG_LINUXBOOT_UROOT_INITCMD) \
-		CONFIG_LINUXBOOT_UROOT_UINITCMD=$(CONFIG_LINUXBOOT_UROOT_UINITCMD)\
+		CONFIG_LINUXBOOT_UROOT_UINITCMD=$(CONFIG_LINUXBOOT_UROOT_UINITCMD) \
 		CONFIG_LINUXBOOT_UROOT_SHELL=$(CONFIG_LINUXBOOT_UROOT_SHELL) \
 		CONFIG_LINUXBOOT_UROOT_COMMANDS=$(CONFIG_LINUXBOOT_UROOT_COMMANDS) \
 		CONFIG_LINUXBOOT_UROOT_FILES=$(CONFIG_LINUXBOOT_UROOT_FILES) \
-		CONFIG_LINUXBOOT_DTB_FILE=$(CONFIG_LINUXBOOT_DTB_FILE)
-
-payloads/external/LinuxBoot/linuxboot/bzImage: linuxboot
-payloads/external/LinuxBoot/linuxboot/uImage: linuxboot
-payloads/external/LinuxBoot/linuxboot/initramfs_u-root.cpio: linuxboot
+		CONFIG_LINUXBOOT_DTS_FILE=$(CONFIG_LINUXBOOT_DTS_FILE)
 
 # BOOTBOOT