Add script for generating per-arch vmlinux.h files

This script iterates over a list archs and generates vmlinux.h for each.
Generated files are put under the corresponding arch directory

Signed-off-by: Ming Yang <minos.future@gmail.com>

scripts/gen_vmlinux_h.sh

@@ -0,0 +1,112 @@
+#!/bin/bash
+
+# Prerequisite
+#
+# * .config is ready in the linux repo
+# * binary bpftool is installed
+# * can `sudo apt install` cross-compile toolchains
+#
+# Example
+#
+# ./scripts/gen_vmlinux_h.sh /path/to/linux ./sched/include/arch/
+
+LINUX_REPO="$1" # where the linux repo is located
+pushd ${LINUX_REPO}
+INCLUDE_TARGET=$2 # target directory, e.g., /path/to/scx/sched/include/arch/
+HASH=$(git rev-parse HEAD)
+SHORT_SHA=${HASH:0:12} # full SHA of the commit truncated to 12 chars
+LINUX_VER=$(git describe --tags --abbrev=0)
+
+# List of architectures and their corresponding cross-compilers
+declare -A ARCHS
+ARCHS=(
+    [x86]="x86_64-linux-gnu-"
+    [arm]="arm-linux-gnueabi-"
+    [arm64]="aarch64-linux-gnu-"
+    [mips]="mips64-linux-gnu-"
+    [powerpc]="powerpc64le-linux-gnu-"
+    [riscv]="riscv64-linux-gnu-"
+    [s390]="s390x-linux-gnu-"
+)
+
+# Detect and install cross-compile toolchains based on the package manager
+install_toolchains() {
+    echo "Installing cross-compile toolchains..."
+
+    if command -v apt &> /dev/null; then
+        sudo apt update && sudo apt install -y \
+            gcc-aarch64-linux-gnu gcc-x86-64-linux-gnu \
+            gcc-arm-linux-gnueabi gcc-mips64-linux-gnuabi64 \
+            gcc-powerpc64le-linux-gnu gcc-riscv64-linux-gnu \
+            gcc-s390x-linux-gnu
+    elif command -v dnf &> /dev/null; then
+        sudo dnf install -y \
+            gcc-aarch64-linux-gnu gcc-x86_64-linux-gnu \
+            gcc-arm-linux-gnu gcc-mips64-linux-gnuabi64 \
+            gcc-powerpc64-linux-gnu gcc-riscv64-linux-gnu \
+            gcc-s390x-linux-gnu
+    elif command -v yum &> /dev/null; then
+        sudo yum install -y \
+            gcc-aarch64-linux-gnu gcc-x86_64-linux-gnu \
+            gcc-arm-linux-gnu gcc-mips64-linux-gnuabi64 \
+            gcc-powerpc64-linux-gnu gcc-riscv64-linux-gnu \
+            gcc-s390x-linux-gnu
+    elif command -v pacman &> /dev/null; then
+        sudo pacman -Sy --noconfirm \
+            aarch64-linux-gnu-gcc x86_64-linux-gnu-gcc \
+            arm-linux-gnueabi-gcc mips64-linux-gnu-gcc \
+            powerpc64le-linux-gnu-gcc riscv64-linux-gnu-gcc \
+            s390x-linux-gnu-gcc
+    elif command -v zypper &> /dev/null; then
+        sudo zypper install -y \
+            gcc-aarch64-linux-gnu gcc-x86_64-linux-gnu \
+            gcc-arm-linux-gnueabi gcc-mips64-linux-gnuabi64 \
+            gcc-powerpc64le-linux-gnu gcc-riscv64-linux-gnu \
+            gcc-s390x-linux-gnu
+    else
+        echo "Unsupported package manager. Please install cross-compilers manually."
+        exit 1
+    fi
+}
+
+# Function to compile the kernel and generate vmlinux.h for a given architecture
+generate_vmlinux_for_arch() {
+    ARCH=$1
+    CROSS_COMPILE=${ARCHS[$ARCH]}
+    TARGET_DIR=${INCLUDE_TARGET}/${ARCH}
+    OUTPUT_FILE="${TARGET_DIR}/vmlinux-${LINUX_VER}-g${SHORT_SHA}.h"
+    mkdir -p ${TARGET_DIR}
+
+    LOG="/tmp/${ARCH}.log"
+    echo "" > ${LOG}
+    echo "Writing compile logs to ${LOG}"
+
+    make ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE} olddefconfig 2>&1 >> ${LOG}
+    make ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE} -j$(nproc) vmlinux 2>&1 >> ${LOG}
+
+    if [ -f ./vmlinux ]; then
+        echo "Generating ${OUTPUT_FILE}..."
+        bpftool btf dump file ./vmlinux format c > "${OUTPUT_FILE}"
+        echo "${OUTPUT_FILE} generated successfully."
+    else
+        echo "Failed to generate vmlinux for ${ARCH}. Please check the compilation process."
+    fi
+}
+
+if ! command -v bpftool &> /dev/null
+then
+    echo "bpftool could not be found. Please install it first."
+    exit 1
+fi
+
+install_toolchains
+
+echo "Start generating vmlinux.h for each arch: "
+for ARCH in "${!ARCHS[@]}"; do
+    echo "Processing architecture: $ARCH"
+    generate_vmlinux_for_arch $ARCH
+done
+
+echo "All architectures processed."
+
+popd