add riscv64 kernels to kernel/Makefile and kernel/Dockerfile.*, riscv64 kernel config, bump alpine version for kernel builds

Signed-off-by: Avi Deitcher <avi@deitcher.net>

docs/kernels.md

@@ -274,7 +274,7 @@ your local Docker setup.
 
 The process of modifying the kernel configuration is as follows:
 
-1. Create a `linuxkit/kconfig` container image: `make kconfig`. This is not pushed out.
+1. Create a `linuxkit/kconfig` container image: `make kconfig`. This is not pushed out. By default, this will be for your local architecture, but you can override it with `make kconfig ARCH=${ARCH}`, e.g. `make kconfig ARCH=arm64`. The image is tagged with the architecture, e.g. `linuxkit/kconfig:arm64`.
 1. Run a container based on `linuxkit/kconfig`.
 1. In the container, modify the config to suit your needs using normal kernel tools like `make defconfig` or `make menuconfig`.
 1. Save the config from the image.
@@ -287,7 +287,11 @@ so that `make menuconfig` and `make defconfig` work correctly.
 Run the container as follows:
 
 ```sh
-docker run --rm -ti -v $(pwd):/src linuxkit/kconfig
+docker run --rm -ti -v $(pwd):/src linuxkit/kconfig:aarch64
+# or
+docker run --rm -ti -v $(pwd):/src linuxkit/kconfig:x86_64
+# or 
+docker run --rm -ti -v $(pwd):/src linuxkit/kconfig:riscv64
 ```
 
 This will give you a interactive shell where you can modify the kernel
@@ -321,6 +325,11 @@ make ARCH=arm64 defconfig
 make ARCH=arm64 oldconfig # or menuconfig
 ```
 
+It is important to note that sometimes the configuration can be subtly different
+when running `make defconfig` across architectures. Of note is that `make ARCH=riscv` on
+x86_64 or aarch64 comes out slightly differently than when run natively on riscv64.
+Feel free to try it cross, but do not be surprised if it generates outputs that are not the same.
+
 Note that the generated file **must** be final. When you actually build the kernel,
 it will check that running `make defconfig` will have no changes. If there are changes,
 the build will fail.

kernel/6.6.x/build-args

@@ -1,3 +1,3 @@
-KERNEL_VERSION=6.6.13
+KERNEL_VERSION=6.6.71
 KERNEL_SERIES=6.6.x
-BUILD_IMAGE=linuxkit/alpine:146f540f25cd92ec8ff0c5b0c98342a9a95e479e
+BUILD_IMAGE=linuxkit/alpine:8c02670fd2e5c28d03fd39db0bddc1379b3af6b2

kernel/Dockerfile

@@ -115,6 +115,9 @@ RUN case $(uname -m) in \
     aarch64) \
         KERNEL_DEF_CONF=/linux/arch/arm64/configs/defconfig; \
         ;; \
+    riscv64) \
+        KERNEL_DEF_CONF=/linux/arch/riscv/configs/defconfig; \
+        ;; \
     esac  && \
     cp /src/${KERNEL_SERIES}/config-$(uname -m) ${KERNEL_DEF_CONF}; \
     if [ -n "${EXTRA}" ] && [ -f "/src/${KERNEL_SERIES}-${EXTRA}/config-$(uname -m)" ]; then \
@@ -139,6 +142,9 @@ RUN make -j "$(getconf _NPROCESSORS_ONLN)" KCFLAGS="-fno-pie" && \
     aarch64) \
         cp arch/arm64/boot/Image.gz /out/kernel; \
         ;; \
+    riscv64) \
+        cp arch/riscv64/boot/Image.gz /out/kernel; \
+        ;; \
     esac && \
     cp System.map /out && \
     ([ -n "${DEBUG}" ] && cp vmlinux /out || true)

kernel/Dockerfile.bcc

@@ -24,6 +24,7 @@ RUN apk update && apk upgrade -a && \
   iperf3 \
   libedit-dev \
   libtool \
+  libxml2 \
   llvm \
   llvm-dev \
   llvm-static \

kernel/Dockerfile.kconfig

@@ -43,8 +43,9 @@ RUN set -e && \
                patch -t -F0 -N -u -p1 < "$patch"; \
            done; \
         fi && \
-        [ ! -f /config-${SERIES}-x86_64 ] || mv /config-${SERIES}-x86_64 arch/x86/configs/x86_64_defconfig && \
+        [ ! -f /config-${SERIES}-x86_64 ] || mv /config-${SERIES}-x86_64 arch/x86/configs/x86_64_defconfig ; \
         [ ! -f /config-${SERIES}-aarch64 ] || mv /config-${SERIES}-aarch64 arch/arm64/configs/defconfig ; \
+        [ ! -f /config-${SERIES}-riscv64 ] || mv /config-${SERIES}-riscv64 arch/riscv64/configs/riscv64_defconfig ; \
     done
 
 ENTRYPOINT ["/bin/sh"]

kernel/Dockerfile.kconfigx

@@ -58,6 +58,9 @@ for VERSION in ${KERNEL_VERSIONS}; do
 	elif [ ${TARGETARCH} = "arm64" ] ; then
 		cp /config-${SERIES}-aarch64 .config
 		ARCH=arm64 make oldconfig
+    elif [ ${TARGETARCH} = "riscv64" ] ; then
+		cp /config-${SERIES}-riscv64 .config
+		ARCH=riscv64 make oldconfig
 	fi
 done
 EOF

kernel/Makefile

@@ -16,7 +16,7 @@ RM = rm -f
 # Name and Org on Hub
 ORG?=linuxkit
 IMAGE?=kernel
-IMAGE_BUILDER=linuxkit/alpine:146f540f25cd92ec8ff0c5b0c98342a9a95e479e
+IMAGE_BUILDER=linuxkit/alpine:8c02670fd2e5c28d03fd39db0bddc1379b3af6b2
 
 # You can specify an extra options for the Makefile. This will:
 # - append a config$(EXTRA) to the kernel config for your kernel/arch
@@ -37,21 +37,23 @@ endif
 REPO_ROOT:=$(shell git rev-parse --show-toplevel)
 
 # determine our architecture
-BUILDERARCH=
+ARCH?=$(shell uname -m)
+BUILDERARCH=$(ARCH)
 ifneq ($(ARCH),)
 ifeq ($(ARCH),$(filter $(ARCH),x86_64 amd64))
 override ARCH=x86_64
-BUILDERARCH=amd64
+override BUILDERARCH=amd64
 endif
 ifeq ($(ARCH),$(filter $(ARCH),aarch64 arm64))
 override ARCH=aarch64
-BUILDERARCH=arm64
+override BUILDERARCH=arm64
+endif
+ifeq ($(ARCH),riscv64)
+override BUILDERARCH=riscv64
 endif
 endif
 
-ifneq ($(BUILDERARCH),)
+BUILD_PLATFORM=linux/$(BUILDERARCH)
-PLATFORMS=--platforms linux/$(BUILDERARCH)
-endif
 
 HASHTAG=$(HASH)$(DIRTY)
 
@@ -124,11 +126,11 @@ buildkerneldeps-%: Dockerfile Makefile $(wildcard patches-$(call series,$*)/*) $
 
 buildplainkernel-%: buildkerneldeps-%
 	$(eval KERNEL_SERIES=$(call series,$*))
-	linuxkit pkg build . $(FORCE) $(PLATFORMS) --build-yml ./build-kernel.yml --tag "$*-{{.Hash}}" --build-arg-file $(KERNEL_SERIES)/build-args 
+	linuxkit pkg build . $(FORCE) --platforms $(BUILD_PLATFORM) --build-yml ./build-kernel.yml --tag "$*-{{.Hash}}" --build-arg-file $(KERNEL_SERIES)/build-args 
 
 builddebugkernel-%: buildkerneldeps-%
 	$(eval KERNEL_SERIES=$(call series,$*))
-	linuxkit pkg build . $(FORCE) $(PLATFORMS) --build-yml ./build-kernel.yml --tag "$*-dbg-{{.Hash}}" --build-arg-file $(KERNEL_SERIES)/build-args --build-arg-file build-args-debug
+	linuxkit pkg build . $(FORCE) --platforms $(BUILD_PLATFORM) --build-yml ./build-kernel.yml --tag "$*-dbg-{{.Hash}}" --build-arg-file $(KERNEL_SERIES)/build-args --build-arg-file build-args-debug
 
 push-%: notdirty build-% pushkernel-% tagbuilder-% pushtools-%;
 
@@ -163,7 +165,7 @@ buildtool-%:
 	$(eval TOOL=$(call toolname,$*))
 	$(eval KERNEL_VERSION=$(call toolkernel,$*))
 	$(eval KERNEL_SERIES=$(call series,$(KERNEL_VERSION)))
-	linuxkit pkg build . $(FORCE) $(PLATFORMS) --build-yml ./build-$(TOOL).yml --tag "$(KERNEL_VERSION)-{{.Hash}}" --build-arg-file $(KERNEL_SERIES)/build-args
+	linuxkit pkg build . $(FORCE) --platforms $(BUILD_PLATFORM) --build-yml ./build-$(TOOL).yml --tag "$(KERNEL_VERSION)-{{.Hash}}" --build-arg-file $(KERNEL_SERIES)/build-args
 
 pushtools-%: $(addprefix pushtool-%$(RELEASESEP),$(TOOLS));
 
@@ -206,34 +208,34 @@ update-kernel-semver-yaml-%:
 update-kernel-yamls: $(addprefix update-kernel-hash-yaml-,$(KERNELS)) update-kernel-semver-yaml-$(KERNEL_HIGHEST);
 
 # Target for kernel config
-kconfig:
+KCONFIG_TAG_EXTENSION=
-ifeq (${KCONFIG_TAG},)
+ifneq (${KCONFIG_TAG},)
-	docker build --no-cache -f Dockerfile.kconfig \
+KCONFIG_TAG_EXTENSION=-${KCONFIG_TAG}
-		--build-arg KERNEL_VERSIONS="$(KERNEL_VERSIONS)" \
-		--build-arg BUILD_IMAGE=$(IMAGE_BUILDER) \
-		-t linuxkit/kconfig  .
-else
-	docker build --no-cache -f Dockerfile.kconfig \
-		--build-arg KERNEL_VERSIONS="$(KERNEL_VERSIONS)" \
-		--build-arg BUILD_IMAGE=$(IMAGE_BUILDER) \
-		-t linuxkit/kconfig:${KCONFIG_TAG}  .
 endif
 
+kconfig:
+	docker build --no-cache -f Dockerfile.kconfig \
+		--build-arg KERNEL_VERSIONS="$(KERNEL_VERSIONS)" \
+		--build-arg BUILD_IMAGE=$(IMAGE_BUILDER) \
+		--platform $(BUILD_PLATFORM) \
+		-t linuxkit/kconfig:$(ARCH)${KCONFIG_TAG_EXTENSION} .
+
 kconfigx:
 ifeq (${KCONFIG_TAG},)
 	docker buildx build --no-cache -f Dockerfile.kconfigx \
-		--platform=$(PLATFORMS) \
+		--platform $(BUILD_PLATFORM) \
 		--output . \
 		--build-arg KERNEL_VERSIONS="$(KERNEL_VERSIONS)" \
 		--build-arg BUILD_IMAGE=$(IMAGE_BUILDER) \
-		-t linuxkit/kconfigx  .
+		-t linuxkit/kconfigx:$(ARCH)  .
 	cp linux_arm64/config-${KERNEL_VERSIONS}-arm64 config-${KERNEL_SERIES}-aarch64
 	cp linux_amd64/config-${KERNEL_VERSIONS}-amd64 config-${KERNEL_SERIES}-x86_64
+	cp linux_amd64/config-${KERNEL_VERSIONS}-riscv64 config-${KERNEL_SERIES}-riscv64
 else
 	docker buildx build --no-cache -f Dockerfile.kconfigx \
-		--platform=$(PLATFORMS) --push \
+		--platform $(BUILD_PLATFORM) --push \
 		--output . \
 		--build-arg KERNEL_VERSIONS="$(KERNEL_VERSIONS)" \
 		--build-arg BUILD_IMAGE=$(IMAGE_BUILDER) \
-		-t linuxkit/kconfigx:${KCONFIG_TAG}  .
+		-t linuxkit/kconfigx:$(ARCH)${KCONFIG_TAG_EXTENSION}  .
 endif