feat(linux): add VIRTUALIZATION workload support

Makefile

@@ -3,14 +3,24 @@ all: workloads
 MULTIHART ?= 0
 PLATFORM ?= $(if $(filter 1,$(MULTIHART)),qemu,nemu)
 HARTS ?= 2
+VIRT_BUILD ?= 0
 QEMU_DEFAULT_DTB ?= xiangshan-qemu-nemu-mem2g
 DTS_ISA_CONFIG ?= kunminghu-v3
 DTS_DIR := build/generated-dts
 export DTS_ISA_CONFIG
 
+ifneq ($(strip $(VIRTUALIZATION)),)
+$(error VIRTUALIZATION was removed; build the Linux image first, then run 'make virt bin=<input.bin-or-directory>')
+endif
+
 ifeq ($(filter $(PLATFORM),nemu qemu),)
 $(error PLATFORM must be either nemu or qemu)
 endif
+ifeq ($(filter 1,$(VIRT_BUILD)),1)
+ifneq ($(filter 1,$(MULTIHART)),)
+$(error VIRT_BUILD=1 does not accept MULTIHART=1; use VIRT_GUEST_HARTS)
+endif
+endif
 ifeq ($(filter $(DTS_ISA_CONFIG),kunminghu-v2 kunminghu-v3),)
 $(error DTS_ISA_CONFIG must be either kunminghu-v2 or kunminghu-v3)
 endif
@@ -22,9 +32,12 @@ endif
 
 LINUX_DEFAULT_DTB := $(if $(DEFAULT_DTB),$(DEFAULT_DTB),$(if $(filter 1,$(MULTIHART)),,$(if $(filter qemu,$(PLATFORM)),$(QEMU_DEFAULT_DTB),)))
 LINUX_FIRMWARE_FILENAME := $(if $(filter qemu,$(PLATFORM)),fw_payload.qemu.bin,fw_payload.bin)
+SBI_BUILD_DIR := $(if $(filter 1,$(MULTIHART)),build/opensbi-multihart,build/opensbi)
+SBI_BIN := $(SBI_BUILD_DIR)/build/platform/generic/firmware/fw_jump.bin
 LINUX_ROOTFS_BUILD_VARS_HASH := $(shell printf '%s\n' \
 	'multihart=$(if $(filter 1,$(MULTIHART)),1,0)' \
-	'harts=$(if $(filter 1,$(MULTIHART)),$(HARTS),1)' | sha256sum | cut -d ' ' -f 1)
+	'harts=$(if $(filter 1,$(MULTIHART)),$(HARTS),1)' \
+	'virt_build=$(VIRT_BUILD)' | sha256sum | cut -d ' ' -f 1)
 LINUX_FIRMWARE_BUILD_VARS_HASH := $(shell printf '%s\n' \
 	'multihart=$(if $(filter 1,$(MULTIHART)),1,0)' \
 	'harts=$(if $(filter 1,$(MULTIHART)),$(HARTS),1)' \
@@ -69,11 +82,121 @@ $(LINUX_IMAGE): $(TOOLCHAIN_WRAPPER) br2-external/configs/nemu_defconfig br2-ext
 	$(MAKE) -C $(BUILDROOT_DIR) BR2_EXTERNAL=$(abspath br2-external) nemu_defconfig
 	$(MAKE) -C $(BUILDROOT_DIR) BR2_EXTERNAL=$(abspath br2-external)
 
+ifeq ($(VIRT_BUILD),1)
+virt: virt-inner
+else
+.PHONY: virt
+virt:
+	@test -n "$(bin)" || { echo 'Usage: make virt bin=<input.bin-or-directory>' >&2; exit 2; }
+	@if test -d "$(bin)"; then \
+		found=0; \
+		for input in "$(abspath $(bin))"/*.bin; do \
+			test -f "$$input" || continue; \
+			found=1; \
+			$(MAKE) --no-print-directory VIRT_BUILD=1 bin="$$input" virt-inner || exit $$?; \
+		done; \
+		test "$$found" -eq 1 || { echo "No .bin inputs found in $(bin)" >&2; exit 2; }; \
+	elif test -f "$(bin)"; then \
+		$(MAKE) --no-print-directory VIRT_BUILD=1 bin="$(abspath $(bin))" $(if $(elf),elf="$(abspath $(elf))") virt-inner; \
+	else \
+		echo "Input is not a regular file or directory: $(bin)" >&2; \
+		exit 2; \
+	fi
+endif
+
+# Combine an existing image export with the per-case virtual packages without
+# changing either source tree.
+IMAGE_DIR ?= build/images/spec2006
+VIRT_DIR ?= build/virt
+VIRT_IMAGE_DIR ?= $(IMAGE_DIR)-virt
+.PHONY: virt-images
+virt-images:
+	@python3 scripts/merge-virt-image-dir.py --image-dir "$(IMAGE_DIR)" --virt-dir "$(VIRT_DIR)" --output-dir "$(VIRT_IMAGE_DIR)"
+
+ifeq ($(VIRT_BUILD),1)
+VIRT_GUEST_HARTS ?= 1
+VIRT_GUEST_MEMORY ?= 8G
+VIRT_QEMU_START_TIMEOUT ?= 120
+VIRT_INNER_QEMU_VERSION := 11.0.0
+VIRT_HOST_BUILDROOT_DIR ?= build/buildroot-virt-host
+VIRT_HOST_CONFIG := $(VIRT_HOST_BUILDROOT_DIR)/.config
+VIRT_HOST_DEFCONFIG := br2-external/configs/nemu_virt_host_defconfig
+VIRT_HOST_LINUX_CONFIG := br2-external/board/openxiangshan/nemu/linux-virt-host.config
+ifeq ($(filter qemu,$(PLATFORM)),qemu)
+VIRT_HOST_DTB ?= xiangshan-qemu-nemu-mem16g
+VIRT_OUTER_QEMU_ARGS := --outer-qemu-machine nemu --outer-qemu-cpu rv64,h=true,sstc=false --outer-qemu-harts 1 --outer-qemu-memory 16G
+else
+VIRT_HOST_DTB ?= xiangshan-fpga-noAIA-mem16g-novec
+VIRT_OUTER_QEMU_ARGS :=
+endif
+VIRT_HOST_FIRMWARE := $(LINUX_FIRMWARE_FILENAME)
+VIRT_HOST_MIN_MEMORY_BYTES ?= 17179869184
+VIRT_HOST_BUILD_STAMP := $(VIRT_HOST_BUILDROOT_DIR)/.build-complete.stamp
+VIRT_HOST_IMAGE := $(VIRT_HOST_BUILDROOT_DIR)/images/Image
+VIRT_HOST_ROOTFS := $(VIRT_HOST_BUILDROOT_DIR)/images/rootfs.cpio
+VIRT_HOST_QEMU := $(VIRT_HOST_BUILDROOT_DIR)/target/usr/bin/qemu-system-riscv64
+VIRT_FAKEROOT := $(BUILDROOT_DIR)/output/host/bin/fakeroot
+VIRT_GCPT_BUILD_DIR := build/LibCheckpointAlpha-virt
+VIRT_GCPT_BIN := $(VIRT_GCPT_BUILD_DIR)/build/gcpt.bin
+VIRT_GCPT_SOURCES := $(shell find bootloader/LibCheckpointAlpha -path '*/.git' -prune -o -type f -print 2>/dev/null)
+VIRT_GCPT_DTS_SOURCES := dts/generate-nemu-board-dts.py dts/DTSGen.py dts/workload-builder-profiles.json
+VIRT_GCPT_CONFIG_STAMP := build/LibCheckpointAlpha-virt-config/config.$(shell printf '%s\n' '$(VIRT_HOST_DTB)' | sha256sum | cut -d ' ' -f 1)
+VIRT_BUILD_VARS_CONTENT := input=$(abspath $(bin))\nelf=$(if $(elf),$(abspath $(elf)))\nplatform=$(PLATFORM)\nguest_harts=$(VIRT_GUEST_HARTS)\nguest_memory=$(VIRT_GUEST_MEMORY)\nqemu_start_timeout=$(VIRT_QEMU_START_TIMEOUT)\ninner_qemu_version=$(VIRT_INNER_QEMU_VERSION)\nhost_dtb=$(VIRT_HOST_DTB)\nhost_min_memory=$(VIRT_HOST_MIN_MEMORY_BYTES)
+VIRT_BUILD_VARS_HASH := $(shell printf '%b' '$(VIRT_BUILD_VARS_CONTENT)' | sha256sum | cut -d ' ' -f 1)
+
+$(VIRT_HOST_CONFIG): $(BUILDROOT_DIR)/Makefile $(VIRT_HOST_DEFCONFIG) $(VIRT_HOST_LINUX_CONFIG)
+	mkdir -p "$(VIRT_HOST_BUILDROOT_DIR)"
+	@if test -f "$@"; then $(MAKE) -C $(BUILDROOT_DIR) O=$(abspath $(VIRT_HOST_BUILDROOT_DIR)) BR2_EXTERNAL=$(abspath br2-external) linux-dirclean qemu-dirclean; fi
+	$(MAKE) -C $(BUILDROOT_DIR) O=$(abspath $(VIRT_HOST_BUILDROOT_DIR)) BR2_EXTERNAL=$(abspath br2-external) nemu_virt_host_defconfig
+
+$(VIRT_HOST_BUILD_STAMP): $(VIRT_HOST_CONFIG) $(VIRT_HOST_DEFCONFIG) $(VIRT_HOST_LINUX_CONFIG)
+	$(MAKE) -C $(BUILDROOT_DIR) O=$(abspath $(VIRT_HOST_BUILDROOT_DIR)) BR2_EXTERNAL=$(abspath br2-external)
+	test -s "$(VIRT_HOST_IMAGE)"
+	test -s "$(VIRT_HOST_ROOTFS)"
+	test -x "$(VIRT_HOST_QEMU)"
+	@test -n "$$(find "$(VIRT_HOST_BUILDROOT_DIR)/build" -maxdepth 1 -type d -name 'qemu-*' -print -quit)"
+	@host_kernel_config="$$(find "$(VIRT_HOST_BUILDROOT_DIR)/build" -path '*/linux-*/.config' -print -quit)"; test -n "$$host_kernel_config"; grep -qx 'CONFIG_VIRTUALIZATION=y' "$$host_kernel_config"; grep -qx 'CONFIG_KVM=y' "$$host_kernel_config"
+	touch "$@"
+
+$(VIRT_GCPT_CONFIG_STAMP):
+	mkdir -p "$(@D)"
+	rm -f "$(@D)"/config.*
+	touch "$@"
+
+$(VIRT_GCPT_BIN): scripts/build-gcpt.sh scripts/dts-config.sh $(TOOLCHAIN_WRAPPER) $(VIRT_GCPT_CONFIG_STAMP) $(VIRT_GCPT_SOURCES) $(VIRT_GCPT_DTS_SOURCES)
+	CROSS_COMPILE="$(abspath $(BUILDROOT_DIR)/output/host/bin)/riscv64-linux-" GCPT_IMPLEMENTATION=alpha DEFAULT_DTB="$(VIRT_HOST_DTB)" DTS_TEMPLATE_DIR="$(abspath $(DTS_DIR))" bash scripts/build-gcpt.sh bootloader/LibCheckpointAlpha $(VIRT_GCPT_BUILD_DIR)
+
+VIRT_INPUT_NAME := $(notdir $(bin))
+VIRT_INPUT_CASE := $(if $(filter fw_payload.bin fw_payload.qemu.bin,$(VIRT_INPUT_NAME)),$(notdir $(patsubst %/,%,$(dir $(bin)))),$(if $(filter %.fw_payload.qemu.bin,$(VIRT_INPUT_NAME)),$(patsubst %.fw_payload.qemu.bin,%,$(VIRT_INPUT_NAME)),$(if $(filter %.fw_payload.bin,$(VIRT_INPUT_NAME)),$(patsubst %.fw_payload.bin,%,$(VIRT_INPUT_NAME)),$(patsubst %.bin,%,$(VIRT_INPUT_NAME)))))
+VIRT_INPUT_DIR := build/virt/$(VIRT_INPUT_CASE)
+VIRT_INPUT_VARS := $(VIRT_INPUT_DIR)/vars.$(VIRT_BUILD_VARS_HASH).stamp
+VIRT_INPUT_PACKAGE := $(VIRT_INPUT_DIR)/package.stamp
+VIRT_INPUT_FIRMWARE := $(VIRT_INPUT_DIR)/host/$(VIRT_HOST_FIRMWARE)
+
+$(VIRT_INPUT_VARS):
+	@mkdir -p "$(@D)"
+	@rm -f "$(@D)"/vars.*.stamp
+	@printf '%b\n' '$(VIRT_BUILD_VARS_CONTENT)' > "$@"
+
+$(VIRT_INPUT_PACKAGE): $(bin) $(if $(elf),$(abspath $(elf))) $(VIRT_HOST_BUILD_STAMP) $(VIRT_INPUT_VARS) scripts/build-virtual-workload.py
+	@test -n "$(bin)" || { echo 'Usage: make virt bin=<input.bin>' >&2; exit 2; }
+	@mkdir -p "$(VIRT_INPUT_DIR)"
+	@$(VIRT_FAKEROOT) -- python3 scripts/build-virtual-workload.py input-package --input-bin "$(abspath $(bin))" $(if $(elf),--input-elf "$(abspath $(elf))") --host-rootfs "$(VIRT_HOST_ROOTFS)" --host-image "$(VIRT_HOST_IMAGE)" --guest-buildroot-output "$(BUILDROOT_DIR)/output" --host-buildroot-output "$(VIRT_HOST_BUILDROOT_DIR)" --out-dir "$(VIRT_INPUT_DIR)" --guest-harts "$(VIRT_GUEST_HARTS)" --guest-memory "$(VIRT_GUEST_MEMORY)" --qemu-start-timeout "$(VIRT_QEMU_START_TIMEOUT)"
+	@touch "$@"
+
+$(VIRT_INPUT_FIRMWARE): $(VIRT_INPUT_PACKAGE) $(VIRT_GCPT_BIN) $(SBI_BIN) $(VIRT_GCPT_DTS_SOURCES) scripts/build-firmware-linux.sh scripts/dts-config.sh
+	@CROSS_COMPILE="$(abspath $(BUILDROOT_DIR)/output/host/bin)/riscv64-linux-" DTC="$(abspath $(BUILDROOT_DIR)/output/host/bin/dtc)" DEFAULT_DTB="$(VIRT_HOST_DTB)" DTB_MIN_MEMORY_BYTES="$(VIRT_HOST_MIN_MEMORY_BYTES)" INITRAMFS_OFFSET_ALIGNMENT_MB=2 MULTIHART=0 HARTS=1 FIRMWARE_OUTPUT="$@" bash scripts/build-firmware-linux.sh "$(VIRT_GCPT_BIN)" "$(SBI_BUILD_DIR)" "$(DTS_DIR)" "$(VIRT_INPUT_DIR)/host/Image" "$(VIRT_INPUT_DIR)/host"
+
+$(VIRT_INPUT_DIR)/manifest.json: $(VIRT_INPUT_PACKAGE) $(VIRT_INPUT_FIRMWARE) scripts/build-virtual-workload.py
+	@$(VIRT_FAKEROOT) -- python3 scripts/build-virtual-workload.py manifest --out-dir "$(VIRT_INPUT_DIR)" --workload-name "$(VIRT_INPUT_CASE)" --platform "$(PLATFORM)" --guest-harts "$(VIRT_GUEST_HARTS)" --guest-memory "$(VIRT_GUEST_MEMORY)" --qemu-start-timeout "$(VIRT_QEMU_START_TIMEOUT)" --inner-qemu-version "$(VIRT_INNER_QEMU_VERSION)" --host-dtb "$(VIRT_HOST_DTB)" --host-min-memory-bytes "$(VIRT_HOST_MIN_MEMORY_BYTES)" $(VIRT_OUTER_QEMU_ARGS) --gcpt "$(VIRT_GCPT_BIN)" --opensbi "$(SBI_BIN)" --host-linux-revision "buildroot-selected" --opensbi-source bootloader/opensbi --opensbi-revision "$(shell git -C bootloader/opensbi rev-parse HEAD 2>/dev/null || printf unknown)" --host-defconfig "$(VIRT_HOST_DEFCONFIG)" --host-linux-config "$(VIRT_HOST_LINUX_CONFIG)" --guest-buildroot-output "$(BUILDROOT_DIR)/output" --host-buildroot-output "$(VIRT_HOST_BUILDROOT_DIR)" --buildroot-source "$(BUILDROOT_DIR)"
+
+virt-inner: $(VIRT_INPUT_DIR)/manifest.json
+	@printf '[virt] Output written to %s\n' "$(abspath $(VIRT_INPUT_DIR))"
+
+endif
+
 # Build GCPT. Single-core firmware keeps LibCheckpointAlpha; LibCheckpoint is
 # used for the QEMU multi-hart checkpoint format.
-SBI_BUILD_DIR := $(if $(filter 1,$(MULTIHART)),build/opensbi-multihart,build/opensbi)
-SBI_BIN := $(SBI_BUILD_DIR)/build/platform/generic/firmware/fw_jump.bin
-
 GCPT_IMPLEMENTATION := $(if $(filter 1,$(MULTIHART)),libcheckpoint,alpha)
 GCPT_SOURCE_DIR := $(if $(filter 1,$(MULTIHART)),bootloader/LibCheckpoint,bootloader/LibCheckpointAlpha)
 GCPT_BUILD_DIR := $(if $(filter 1,$(MULTIHART)),build/LibCheckpoint,build/LibCheckpointAlpha)
@@ -191,9 +314,11 @@ AM_WORKLOAD_DIRS := $(patsubst workloads/am/%/build.sh,%,$(wildcard workloads/am
 LINUX_GENERIC_WORKLOADS := $(sort $(filter-out $(LINUX_WORKLOAD_RULE_DIRS),$(LINUX_WORKLOAD_DIRS)))
 AM_GENERIC_WORKLOADS := $(sort $(filter-out $(AM_WORKLOAD_RULE_DIRS),$(AM_WORKLOAD_DIRS)))
 # QEMU support covers the Linux workloads with QEMU-compatible firmware flows.
+# Virtualization consumes a prebuilt input and does not alter workload registration.
 QEMU_SUPPORTED_LINUX_WORKLOADS := coremark spec2006 spec2017
-LINUX_ENABLED_GENERIC_WORKLOADS := $(if $(filter qemu,$(PLATFORM)),$(filter $(QEMU_SUPPORTED_LINUX_WORKLOADS),$(LINUX_GENERIC_WORKLOADS)),$(LINUX_GENERIC_WORKLOADS))
-LINUX_WORKLOAD_RULE_FILES := $(if $(filter qemu,$(PLATFORM)),$(wildcard $(foreach workload,$(QEMU_SUPPORTED_LINUX_WORKLOADS),workloads/linux/$(workload)/rules.mk)),$(wildcard workloads/linux/*/rules.mk))
+LINUX_QEMU_SUPPORTED_ONLY := $(filter qemu,$(PLATFORM))
+LINUX_ENABLED_GENERIC_WORKLOADS := $(if $(LINUX_QEMU_SUPPORTED_ONLY),$(filter $(QEMU_SUPPORTED_LINUX_WORKLOADS),$(LINUX_GENERIC_WORKLOADS)),$(LINUX_GENERIC_WORKLOADS))
+LINUX_WORKLOAD_RULE_FILES := $(if $(LINUX_QEMU_SUPPORTED_ONLY),$(wildcard $(foreach workload,$(QEMU_SUPPORTED_LINUX_WORKLOADS),workloads/linux/$(workload)/rules.mk)),$(wildcard workloads/linux/*/rules.mk))
 
 $(foreach workload,$(LINUX_ENABLED_GENERIC_WORKLOADS),$(eval $(call add_workload_linux,$(workload))))
 $(foreach workload,$(AM_GENERIC_WORKLOADS),$(eval $(call add_workload_am,$(workload))))
@@ -220,7 +345,7 @@ source: $(BUILDROOT_DIR)/Makefile
 	make -C $(BUILDROOT_DIR) BR2_EXTERNAL=$(abspath br2-external) nemu_defconfig
 	make -C $(BUILDROOT_DIR) BR2_EXTERNAL=$(abspath br2-external) source
 
-# Build all all-in-one firmware images
+# Build all all-in-one firmware images, or their virtual counterparts
 workloads: $(WORKLOADS_LINUX) $(WORKLOADS_AM_SENTINEL)
 
 # Build all rootfs

README.md

@@ -25,6 +25,62 @@ You can also build a single workload with:
 - `make linux/workload_name` for a Linux workload.
 - `make am/workload_name` for an AM workload.
 
+To package an already-built Linux firmware, or a bare-metal binary linked for
+the standard QEMU `virt` machine, as a nested KVM Guest, pass its bin explicitly
+to the independent `virt` target. A directory processes each direct child
+`*.bin` input independently:
+
+```shell
+make spec2006-images BENCH=bzip2 INPUT=chicken SPEC2006_ISO=/path/to/cpu2006.iso
+make virt bin=build/images/spec2006/bin/bzip2_chicken.fw_payload.bin
+make virt bin=build/images/spec2006/bin
+```
+
+To combine an existing image export and its matching virtual packages into a
+new image directory, run:
+
+```shell
+make virt-images \
+  IMAGE_DIR=build/images/spec2006 \
+  VIRT_DIR=build/virt \
+  VIRT_IMAGE_DIR=build/images/spec2006-virt
+```
+
+The output keeps the original image layout. For each virtual case, `bin/`
+contains the Host firmware, `kernel/`, `rootfs/`, and `dt/` contain its Host
+components, while the workload ELF, command, configuration, and logs come from
+the original image directory. Host GCPT and OpenSBI artifacts replace their
+Guest counterparts. `manifest/<case>.json` describes the reorganized files and
+links to the full virtual manifest under `manifest/virt/`. Virtual packages
+without a matching `bin/<case>.fw_payload.bin` in `IMAGE_DIR` are ignored.
+Neither source directory is modified. By default, the three paths above are
+`build/images/spec2006`, `build/virt`, and `build/images/spec2006-virt`
+respectively. `VIRT_IMAGE_DIR` must not already exist.
+
+For Linux firmware, `virt` scans the supplied image for its RISC-V Linux Image,
+FDT and initramfs addresses; it does not assume a fixed 4 MiB guest-image
+offset. A bare-metal `.bin` is booted directly as the Guest kernel and must
+already target QEMU `virt`, write its terminal status as
+`VIRT_WORKLOAD_EXIT=<0..255>`. If a matching ELF is not present in the sibling
+`elf/` directory, `virt` creates a minimal ELF load wrapper at `0x80000000` and
+records it in `build/virt/<case>/`.
+The input bin/ELF are consumed as-is and are never rebuilt by `virt`.
+
+The images are exported with the usual SPEC CPU2006 image command:
+
+```shell
+make spec2006-images BENCH=bzip2 INPUT=chicken \
+  SPEC2006_ISO=/path/to/cpu2006.iso -jN
+```
+
+It writes the virtual Host firmware, device tree and manifest into
+`build/virt/<case>/`. Inputs with the same case name share that output
+directory.
+
+`PLATFORM=nemu` uses the FPGA host DTB (`xiangshan-fpga-noAIA-mem16g-novec` by
+default); `PLATFORM=qemu` uses the QEMU `nemu` host DTB
+(`xiangshan-qemu-nemu-mem16g` by default). Override either with `VIRT_HOST_DTB`.
+
 Single-core workloads default to NEMU. QEMU support covers CoreMark, SPEC
 CPU2006, and SPEC CPU2017, which can be assembled with `PLATFORM=qemu`:
 

br2-external/board/openxiangshan/nemu/linux-virt-host.config

@@ -0,0 +1,63 @@
+CONFIG_SYSVIPC=y
+CONFIG_NO_HZ_IDLE=y
+CONFIG_HIGH_RES_TIMERS=y
+# CONFIG_BPF_SYSCALL is not set
+# CONFIG_CGROUPS is not set
+CONFIG_BLK_DEV_INITRD=y
+CONFIG_INITRAMFS_SOURCE=""
+# CONFIG_RD_GZIP is not set
+# CONFIG_RD_BZIP2 is not set
+# CONFIG_RD_LZMA is not set
+# CONFIG_RD_XZ is not set
+# CONFIG_RD_LZO is not set
+# CONFIG_RD_LZ4 is not set
+# CONFIG_RD_ZSTD is not set
+# CONFIG_INITRAMFS_PRESERVE_MTIME is not set
+CONFIG_NONPORTABLE=y
+CONFIG_SMP=y
+# CONFIG_RISCV_BOOT_SPINWAIT is not set
+# CONFIG_COMPAT is not set
+# CONFIG_EFI is not set
+# CONFIG_SUSPEND is not set
+CONFIG_VIRTUALIZATION=y
+CONFIG_KVM=y
+CONFIG_JUMP_LABEL=y
+# CONFIG_GCC_PLUGINS is not set
+CONFIG_NET=y
+CONFIG_UNIX=y
+# CONFIG_PACKET is not set
+# CONFIG_INET is not set
+# CONFIG_WIRELESS is not set
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+# CONFIG_NETDEVICES is not set
+# CONFIG_LEGACY_PTYS is not set
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_8250_DW=y
+CONFIG_SERIAL_OF_PLATFORM=y
+CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
+CONFIG_SERIAL_UARTLITE=y
+CONFIG_SERIAL_SIFIVE=y
+CONFIG_SERIAL_SIFIVE_CONSOLE=y
+CONFIG_HVC_RISCV_SBI=y
+# CONFIG_HW_RANDOM is not set
+# CONFIG_I2C is not set
+# CONFIG_FB is not set
+# CONFIG_HID_SUPPORT is not set
+# CONFIG_USB_SUPPORT is not set
+# CONFIG_VIRTIO_MENU is not set
+# CONFIG_VHOST_MENU is not set
+# CONFIG_IOMMU_SUPPORT is not set
+# CONFIG_RPMSG is not set
+# CONFIG_EXT4_FS is not set
+# CONFIG_FAT_FS is not set
+CONFIG_TMPFS=y
+# CONFIG_HUGETLBFS is not set
+# CONFIG_CONFIGFS_FS is not set
+# CONFIG_MISC_FILESYSTEMS is not set
+# CONFIG_NLS is not set
+CONFIG_PRINTK_TIME=y
+# CONFIG_RUNTIME_KERNEL_TESTING_MENU is not set
+# CONFIG_RUNTIME_TESTING_MENU is not set
+

br2-external/configs/nemu_virt_host_defconfig

@@ -0,0 +1,19 @@
+BR2_riscv=y
+BR2_RISCV_ISA_RVC=y
+BR2_TOOLCHAIN_EXTERNAL=y
+BR2_TARGET_GENERIC_HOSTNAME="xiangshan-virt-host"
+BR2_TARGET_GENERIC_ISSUE="Xiangshan NEMU virtualization host"
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
+BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="${BR2_EXTERNAL}/board/openxiangshan/nemu/linux-virt-host.config"
+BR2_TARGET_ROOTFS_CPIO=y
+BR2_TARGET_ROOTFS_CPIO_FULL=y
+BR2_TARGET_ROOTFS_CPIO_NONE=y
+BR2_PACKAGE_BUSYBOX_CONFIG_FRAGMENT_FILES="${BR2_EXTERNAL}/board/openxiangshan/nemu/busybox-taskset.fragment"
+BR2_PACKAGE_NEMU_TRAP=y
+BR2_PACKAGE_QEMU=y
+BR2_PACKAGE_QEMU_SYSTEM=y
+BR2_PACKAGE_QEMU_CHOOSE_TARGETS=y
+BR2_PACKAGE_QEMU_TARGET_RISCV64=y
+
+

scripts/build-firmware-linux.sh

@@ -13,6 +13,7 @@ DEFAULT_DTB="${DEFAULT_DTB:-}"
 DTB_MEMORY_PROFILE="${DTB_MEMORY_PROFILE:-}"
 DTB_MIN_MEMORY_BYTES="${DTB_MIN_MEMORY_BYTES:-}"
 DTB_REQUIRED_MIN_MEMORY_BYTES="${DTB_REQUIRED_MIN_MEMORY_BYTES:-}"
+INITRAMFS_OFFSET_ALIGNMENT_MB="${INITRAMFS_OFFSET_ALIGNMENT_MB:-1}"
 HARTS="${HARTS:-2}"
 readonly MULTIHART_MAX_HARTS=128
 readonly MULTIHART_KERNEL_OFFSET_MB=134
@@ -76,6 +77,18 @@ KERNEL_BEGIN_ADDR="$(dts_linux_kernel_address "$MEM_BEGIN" "$((KERNEL_MIN_OFFSET
 KERNEL_END_ADDR=$(( KERNEL_BEGIN_ADDR + KERNEL_SIZE ))
 KERNEL_OFFSET_KB=$(( (KERNEL_BEGIN_ADDR - MEM_BEGIN) / KILOBYTE ))
 INITRAMFS_BEGIN_ADDR=$(( (KERNEL_END_ADDR + MEGABYTE - 1) / MEGABYTE * MEGABYTE ))
+case "$INITRAMFS_OFFSET_ALIGNMENT_MB" in
+    ''|*[!0-9]*) echo "INITRAMFS_OFFSET_ALIGNMENT_MB must be a positive integer" >&2; exit 1 ;;
+esac
+if [ "$INITRAMFS_OFFSET_ALIGNMENT_MB" -eq 0 ]; then
+    echo "INITRAMFS_OFFSET_ALIGNMENT_MB must be a positive integer" >&2
+    exit 1
+fi
+INITRAMFS_BEGIN_ADDR=$((
+    (INITRAMFS_BEGIN_ADDR + INITRAMFS_OFFSET_ALIGNMENT_MB * MEGABYTE - 1) /
+    (INITRAMFS_OFFSET_ALIGNMENT_MB * MEGABYTE) *
+    (INITRAMFS_OFFSET_ALIGNMENT_MB * MEGABYTE)
+))
 INITRAMFS_OFFSET_KB=$(( (INITRAMFS_BEGIN_ADDR - MEM_BEGIN) / KILOBYTE ))
 INITRAMFS_SIZE=$(stat -c%s "$CPIO_ARCHIVE")
 INITRAMFS_END_ADDR=$(( INITRAMFS_BEGIN_ADDR + INITRAMFS_SIZE ))