#!/bin/mkpkg
# description: Linux kernel for the rawnix.org netinstall image
# url: https://www.kernel.org/
#
# This is NOT the system kernel port.  It builds the EFI-stub kernel
# with root= compiled into CONFIG_CMDLINE, for use by mkinstall.sh.
# It is never installed on a running system:
#
#   cd /usr/local/src/linux-7.2.11-img && mkpkg -is
#   tar xf linux-7.2.11-img#7.2.11-1.pkg.tar.gz -C /root/

name=linux-7.2.11-img
_name=linux
version=7.2.11
_version=7.2.11-img
release=1
source=(https://cdn.kernel.org/pub/linux/kernel/v7.x/$_name-$version.tar.xz
        config-${_version}
)

sha256sums=(
    "fd0fc479f983a8c05313f13e9c36330fe6651cf725396748c40d5cd93fa1e6a4"
    "eb45de7a3f5e5eeb93c9f9caf99e03b17631751ac4be5b61b34847f13d6c7dfb"
)

build() {
    # A kernel controls its own flags; nothing from mkpkg.conf reaches it.
    unset CFLAGS CXXFLAGS LDFLAGS CPPFLAGS PKG_CONFIG_PATH MAKEFLAGS

    _nm=$SRC/nm-epipe
    rm -f $_nm
    printf '%s\n' \
        '#!/bin/sh' \
        'llvm-nm "$@"' \
        '_s=$?' \
        'if [ $_s -gt 128 ]; then exit 0; fi' \
        'exit $_s' > $_nm
    chmod 755 $_nm
    test -s $_nm || { echo "nm wrapper is empty"; return 1; }

    cd $_name-$version

    cp $SRC/config-${_version} .config
    make LLVM=1 olddefconfig

    # Assert what the image depends on survived olddefconfig.  Each of
    # these is a silent failure otherwise: no EFI_STUB and the firmware
    # will not load the kernel at all, no CMDLINE and it loads and
    # panics with no root device, a wrong LOCALVERSION and the module
    # tree does not match the vmlinuz name mkinstall.sh looks for, no
    # USB and the stick it booted from is gone after handoff.
    grep -q '^CONFIG_LOCALVERSION="-img"' .config || { echo "CONFIG_LOCALVERSION is not -img"; return 1; }
    grep -q '^CONFIG_EFI_STUB=y'         .config || { echo "CONFIG_EFI_STUB lost"; return 1; }
    grep -q '^CONFIG_CMDLINE_BOOL=y'     .config || { echo "CONFIG_CMDLINE_BOOL lost"; return 1; }
    grep -q '^CONFIG_CMDLINE=".*root='   .config || { echo "CONFIG_CMDLINE has no root="; return 1; }
    grep -q '^CONFIG_MODULES=y'          .config || { echo "CONFIG_MODULES not enabled"; return 1; }
    grep -q '^CONFIG_USB=y'              .config || { echo "CONFIG_USB lost"; return 1; }

    make LLVM=1 NM=$_nm -j$(nproc)

    make LLVM=1 NM=$_nm INSTALL_MOD_PATH=$PKG INSTALL_MOD_STRIP=1 modules_install

    install -Dm644 arch/x86/boot/bzImage $PKG/boot/vmlinuz-$_version
    install -Dm644 System.map            $PKG/boot/System.map-$_version
    install -Dm644 .config               $PKG/boot/config-$_version

    rm -f $PKG/lib/modules/$_version/build
    rm -f $PKG/lib/modules/$_version/source
}

signify() {
    untrusted comment: public key
    RWTZ9IduCSQ/mL8337TEUinPwT92xFEUpD92hkS7IxcOnzTt9QdpohT3
}

# vim: filetype=sh