src/util/gensrvimg

#!/bin/sh
#
# Generate a network bootable directory image

set -e
set -u

# Print usage message
#
help() {
    echo "usage: ${0} [OPTIONS] foo.[k]pxe|foo.efi [bar.[k]pxe|bar.efi,...]"
    echo
    echo "where OPTIONS are:"
    echo " -h         show this help"
    echo " -a ARCH    select default CPU architecture [x86_64]"
    echo " -d DIR     install images to directory"
    echo " -e SHIM    specify an EFI shim helper"
    echo " -o FILE    save image archive to file"
}

# Get hex byte from binary file
#
get_byte() {
    local FILENAME
    local OFFSET

    FILENAME="${1}"
    OFFSET="${2}"

    od -j "${OFFSET}" -N 1 -A n -t x1 -- "${FILENAME}" | tr -d " "
}

# Get hex word from binary file
#
get_word() {
    local FILENAME
    local OFFSET
    local LSB
    local MSB

    FILENAME="${1}"
    OFFSET="${2}"

    LSB=$(get_byte "${FILENAME}" $(( ${OFFSET} + 0 )) )
    MSB=$(get_byte "${FILENAME}" $(( ${OFFSET} + 1 )) )
    echo "${MSB}${LSB}"
}

# Get hex dword from binary file
#
get_dword() {
    local FILENAME
    local OFFSET
    local LSW
    local MSW

    FILENAME="${1}"
    OFFSET="${2}"

    LSW=$(get_word "${FILENAME}" $(( ${OFFSET} + 0 )) )
    MSW=$(get_word "${FILENAME}" $(( ${OFFSET} + 2 )) )
    echo "${MSW}${LSW}"
}

# Get appropriate subdirectory name for CPU architecture from EFI binary
#
efi_subdir_name() {
    local FILENAME
    local MZSIG
    local PEOFF
    local PESIG
    local ARCH
    local OPTSIG
    local SECSIZE
    local SBSUFFIX

    FILENAME="${1}"

    MZSIG=$(get_word "${FILENAME}" 0)
    if [ "${MZSIG}" != "5a4d" ] ; then
	echo "${FILENAME}: invalid MZ header" >&2
	exit 1
    fi
    PEOFF=$(get_byte "${FILENAME}" 0x3c)
    PESIG=$(get_word "${FILENAME}" 0x${PEOFF})
    if [ "${PESIG}" != "4550" ] ; then
	echo "${FILENAME}: invalid PE header" >&2
	exit 1
    fi
    ARCH=$(get_word "${FILENAME}" $(( 0x${PEOFF} + 4 )) )
    OPTSIG=$(get_word "${FILENAME}" $(( 0x${PEOFF} + 24 )) )
    case "${OPTSIG}" in
	"010b" )
	    SECSIZE=$(get_dword "${FILENAME}" $(( 0x${PEOFF} + 156 )) )
	    ;;
	"020b" )
	    SECSIZE=$(get_dword "${FILENAME}" $(( 0x${PEOFF} + 172 )) )
	    ;;
	* )
	    echo "${FILENAME}: unrecognised optional header ${OPTSIG}" >&2
	    exit 1
	    ;;
    esac
    if [ "${SECSIZE}" != "00000000" ] ; then
	SBSUFFIX="-sb"
    else
	SBSUFFIX=""
    fi
    case "${ARCH}" in
	"014c" )
	    echo "i386${SBSUFFIX}"
	    ;;
	"8664" )
	    echo "x86_64${SBSUFFIX}"
	    ;;
	"01c2" )
	    echo "arm32${SBSUFFIX}"
	    ;;
	"6264" )
	    echo "loong64${SBSUFFIX}"
	    ;;
	"aa64" )
	    echo "arm64${SBSUFFIX}"
	    ;;
	"5064" )
	    echo "riscv64${SBSUFFIX}"
	    ;;
	"5032" )
	    echo "riscv32${SBSUFFIX}"
	    ;;
	* )
	    echo "${FILENAME}: unrecognised EFI architecture ${ARCH}" >&2
	    exit 1
    esac
}

# Get appropriate subdirectory name for CPU architecture from iPXE NBP
#
nbp_subdir_name() {
    local FILENAME
    local LJMP
    local SEGMENT
    local MAGIC
    local ARCH

    FILENAME="${1}"

    LJMP=$(get_byte "${FILENAME}" 0)
    if [ "${LJMP}" != "ea" ] ; then
	echo "${FILENAME}: invalid LJMP instruction" >&2
	exit 1
    fi
    SEGMENT=$(get_word "${FILENAME}" 3)
    if [ "${SEGMENT}" != "07c0" ] ; then
	echo "${FILENAME}: invalid LJMP segment" >&2
	exit 1
    fi
    MAGIC=$(get_word "${FILENAME}" 6)
    if [ "${MAGIC}" != "18ae" ] ; then
	echo "${FILENAME}: invalid iPXE magic" >&2
	exit 1
    fi
    ARCH=$(get_byte "${FILENAME}" 5)
    case "${ARCH}" in
	"32" )
	    echo "i386"
	    ;;
	"64" )
	    echo "x86_64"
	    ;;
	* )
	    echo "${FILENAME}: unrecognised NBP architecture ${ARCH}" >&2
	    exit 1
    esac
}

# Get appropriate subdirectory name for CPU architecture
#
subdir_name() {
    local FILENAME
    local BYTE

    FILENAME="${1}"

    BYTE=$(get_byte "${FILENAME}" 0)
    case "${BYTE}" in
	"4d" )
	    efi_subdir_name "${FILENAME}"
	    ;;
	"ea" )
	    nbp_subdir_name "${FILENAME}"
	    ;;
	* )
	    echo "${FILENAME}: unrecognised format" >&2
	    exit 1
    esac
}

# Parse command-line options
#
DEFARCH=x86_64
OUTDIR=
OUTFILE=
SHIMAA64=
SHIMX64=
while getopts "ha:d:e:o:" OPTION ; do
    case "${OPTION}" in
	h)
	    help
	    exit 0
	    ;;
	a)
	    DEFARCH="${OPTARG}"
	    ;;
	d)
	    OUTDIR="${OPTARG}"
	    ;;
	e)
	    SHIM="${OPTARG}"
	    SHIMARCH=$(subdir_name "${SHIM}")
	    case "${SHIMARCH}" in
		arm64* )
		    SHIMAA64="${SHIM}"
		    ;;
		x86_64* )
		    SHIMX64="${SHIM}"
		    ;;
		* )
		    echo "${SHIM}: unsupported shim architecture" >&2
		    exit 1
	    esac
	    ;;
	o)
	    OUTFILE="${OPTARG}"
	    ;;
	*)
	    help
	    exit 1
	    ;;
    esac
done
if [ -z "${OUTDIR}" -a -z "${OUTFILE}" ] ; then
    echo "${0}: no output directory or file given" >&2
    help
    exit 1
fi
shift $(( OPTIND - 1 ))
if [ $# -eq 0 ] ; then
    echo "${0}: no input files given" >&2
    help
    exit 1
fi

# Create temporary working directory, if applicable
#
WORKDIR=
if [ -z "${OUTDIR}" ] ; then
    WORKDIR=$(mktemp -d "${OUTFILE}.XXXXXX")
    OUTDIR="${WORKDIR}/ipxeboot"
fi
mkdir -p "${OUTDIR}"

# Copy files to output directory
#
for FILENAME ; do
    SUBDIR=$(subdir_name "${FILENAME}")
    ARCH="${SUBDIR%-sb}"
    DESTDIR="${OUTDIR}/${SUBDIR}"
    BASENAME=$(basename "${FILENAME}")
    SHIMLINK="${BASENAME%.efi}-shim.efi"
    mkdir -p "${DESTDIR}"
    install -m 644 "${FILENAME}" "${DESTDIR}/${BASENAME}"
    case "${SUBDIR}" in
	arm64-sb )
	    if [ -n "${SHIMAA64}" ] ; then
		install -m 644 "${SHIMAA64}" "${DESTDIR}/shimaa64.efi"
		ln -sfn "shimaa64.efi" "${DESTDIR}/${SHIMLINK}"
	    fi
	    ;;
	x86_64-sb )
	    if [ -n "${SHIMX64}" ] ; then
		install -m 644 "${SHIMX64}" "${DESTDIR}/shimx64.efi"
		ln -sfn "shimx64.efi" "${DESTDIR}/${SHIMLINK}"
	    fi
	    ;;
    esac
    if [ "${ARCH}" = "${DEFARCH}" ] ; then
	if [ "${ARCH}" = "${SUBDIR}" ] ; then
	    ln -sfn "${SUBDIR}/${BASENAME}" "${OUTDIR}/${BASENAME}"
	else
	    ln -sfn "${SUBDIR}" "${OUTDIR}/sb"
	fi
    fi
done

# Create output archive file, if applicable
#
if [ -n "${OUTFILE}" ] ; then
    TOPDIR=$(dirname "${OUTDIR}")
    BASENAME=$(basename "${OUTDIR}")
    case "${OUTFILE}" in
	*.tar )
	    tar cf "${OUTFILE}" -C "${TOPDIR}" "${BASENAME}"
	    ;;
	*.tar.gz | *.tgz )
	    tar czf "${OUTFILE}" -C "${TOPDIR}" "${BASENAME}"
	    ;;
	*.tar.bz2 )
	    tar cjf "${OUTFILE}" -C "${TOPDIR}" "${BASENAME}"
	    ;;
	*.tar.xz )
	    tar cJf "${OUTFILE}" -C "${TOPDIR}" "${BASENAME}"
	    ;;
	* )
	    echo "${OUTFILE}: unrecognised archive format" >&2
	    exit 1
	    ;;
    esac
fi

# Clean up temporary working directory
#
if [ -n "${WORKDIR}" ] ; then
    rm -rf "${WORKDIR}"
fi