1 files changed, 79 insertions, 0 deletions
diff --git a/sys-kernel/linux-firmware/files/linux-firmware-make-amd-ucode-img.bash b/sys-kernel/linux-firmware/files/linux-firmware-make-amd-ucode-img.bash
new file mode 100644
index 000000000000..5fac567e063d
--- /dev/null
+++ b/sys-kernel/linux-firmware/files/linux-firmware-make-amd-ucode-img.bash
@@ -0,0 +1,79 @@
+#!/usr/bin/env bash
+
+# Copyright 2024 Gentoo Authors
+
+our_name=${0}
+out=${1}
+in=${2}
+
+# familiar helpers, we intentionally don't use Gentoo functions.sh
+die() {
+    echo -e " ${NOCOLOR-\e[1;31m*\e[0m }${*}" >&2
+    exit 1
+}
+
+einfo() {
+    echo -e " ${NOCOLOR-\e[1;32m*\e[0m }${*}" >&2
+}
+
+main() {
+    # re-define for subst to work
+    [[ -n ${NOCOLOR+yes} ]] && NOCOLOR=
+
+
+    # Set the output file to arg 1 if it's not a directory.
+    # If it's a directory, set the out file to the directory with the default name.
+    # If it's a relative filename, include it in the variable.
+    local ucode_file=${out:-"/boot/amd-uc.img"}
+    if [[ -d ${ucode_file} ]]; then
+        ucode_file="${ucode_file}/amd-uc.img"
+        einfo "Output file is a directory. Using default name: ${ucode_file}"
+    elif [[ ${ucode_file} != /* ]]; then
+        ucode_file="$(pwd)/${ucode_file}"
+        einfo "Output file is a relative path. Using full path: ${ucode_file}"
+    elif [[ -z ${ucode_file} ]]; then
+        einfo "Usage: ${our_name} <output image> <microcode directory>"
+        die "No output file specified"
+    fi
+
+    # Only AMD microcode is in the linux-firmmware package
+    local ucode_dir=${in:-"/lib/firmware/amd-ucode"}
+    if [[ ! -d ${ucode_dir} ]]; then
+        einfo "Usage: ${our_name} <output image> <microcode directory>"
+        die "AMD microcode directory does not exist: ${ucode_dir}"
+    fi
+
+    # Make the tmp dir for the microcode archive
+    local ucode_tmp_dir="$(mktemp -d)" || die "Failed to create temporary directory"
+    einfo "Created temporary directory: ${ucode_tmp_dir}"
+    local ucode_bin_dir="${ucode_tmp_dir}/kernel/x86/microcode"
+    local ucode_bin_file="${ucode_bin_dir}/AuthenticAMD.bin"
+
+    # Write "1" to the early_cpio flag file
+    echo 1 > "${ucode_tmp_dir}/early_cpio" || die
+
+    # Make the directory for the microcode bin files
+    mkdir -p "${ucode_bin_dir}" || die "Failed to create microcode bin directory: ${ucode_bin_dir}"
+
+    # Concatenate all microcode bin files into a single file
+    cat "${ucode_dir}"/*.bin > "${ucode_bin_file}" || die "Failed to concatenate microcode files into: ${ucode_bin_file}"
+
+    # Check that the concatenated file is not empty
+    [[ -s "${ucode_bin_file}" ]] || die "Empty microcode file: ${ucode_bin_file}"
+
+    pushd "${ucode_tmp_dir}" &> /dev/null || die
+    # Create the cpio archive
+    find . -print0 | cpio --quiet --null -o -H newc -R 0:0 > "${ucode_file}" || die "Failed to create microcode archive in: ${ucode_file}"
+    popd &> /dev/null || die
+
+    # Check that the cpio archive is not empty
+    [[ -s "${ucode_file}" ]] || die "Empty microcode archive at: ${ucode_file}"
+
+    einfo "Created microcode archive at: ${ucode_file}"
+    # Clean up the tmp dir
+    rm -r "${ucode_tmp_dir}" || die "Failed to remove temporary directory: ${ucode_tmp_dir}"
+    einfo "Cleaned up temporary directory: ${ucode_tmp_dir}"
+}
+
+main
+