Add kexec test configs for solidrun/honeycomb

the images are called kexectestimage-5.10 and kexectestimage-5.4

They include two kernels, kernel-5.4 and kernel-5.10

Build the images, netboot them, and once they boot, you can test kexec:
kexec kernel-5.4
kexec kernel-5.10

Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>

mainboards/solidrun/honeycomblx2k/Makefile

@@ -44,6 +44,31 @@ u-root:
 usefultargets:
 	echo fetch, uroot, netbootkernel
 
+# the kexectestimage has standard u-root commands, kexec-tools version of kexec, and two
+# test kernels, a 5.10 and a 5.4
+kexectestimage-5.10: kexecconfig-5.10 kexecinitramfs.cpio
+	cp $< linux-5.10/.config
+	(cd linux-5.10 && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make oldconfig && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make -j32)
+	cp linux-5.10/arch/arm64/boot/Image $@
+
+kexectestimage-5.4: kexecconfig-5.4 kexecinitramfs.cpio
+	cp $< linux/.config
+	(cd linux && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make oldconfig && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make -j32)
+	cp linux/arch/arm64/boot/Image $@
+
+kernel-5.4: config-5.4.47 flashinitramfs.cpio
+	cp $< linux/.config
+	(cd linux && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make oldconfig && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make -j32)
+	cp linux/arch/arm64/boot/Image $@
+
+kexecinitramfs.cpio: u-root Makefile kernel-5.4 kernel-5.10
+	GO111MODULE=off GOARCH=arm64 u-root -o $@ -build=bb \
+		-files ~/.ssh/cpu_rsa.pub:key.pub \
+		-files kernel-5.4 -files kernel-5.10 \
+		github.com/u-root/cpu/cmds/cpud \
+		github.com/u-root/u-root/cmds/boot/pxeboot \
+		core \
+
 flashinitramfs.cpio: u-root Makefile
 	GO111MODULE=off GOARCH=arm64 u-root -o $@ -build=bb \
 		-files ~/.ssh/cpu_rsa.pub:key.pub \
@@ -56,6 +81,11 @@ netbootkernel: config-5.4.47 flashinitramfs.cpio
 	(cd linux && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make oldconfig && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make -j32)
 	cp linux/arch/arm64/boot/Image $@
 
+kernel-5.10: config-5.10 flashinitramfs.cpio
+	cp $< linux/.config
+	(cd linux-5.10 && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make oldconfig && CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 make -j32)
+	cp linux-5.10/arch/arm64/boot/Image $@
+
 # These stanzas fetch code.
 fetch: getkernel geturoot 
 
@@ -63,6 +93,10 @@ getkernel:
 	rm -rf linux
 	git clone --depth=1 -b solidrun-honeycomb --single-branch https://github.com/linuxboot/linux
 
+getkernel-5.10:
+	rm -rf linux-5.10
+	git clone --depth=1 -b v5.10 --single-branch https://github.com/torvalds/linux linux-5.10
+
 geturoot:
 	GO111MODULE=off go get -u github.com/u-root/u-root
 	GO111MODULE=off go get -u github.com/u-root/cpu/...

mainboards/solidrun/honeycomblx2k/config-5.4.47

@@ -362,7 +362,8 @@ CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK=y
 # CONFIG_PARAVIRT is not set
 # CONFIG_PARAVIRT_TIME_ACCOUNTING is not set
 CONFIG_KEXEC=y
-# CONFIG_KEXEC_FILE is not set
+CONFIG_KEXEC_FILE=y
+# CONFIG_KEXEC_SIG is not set
 # CONFIG_CRASH_DUMP is not set
 # CONFIG_XEN is not set
 CONFIG_FORCE_MAX_ZONEORDER=11