pmbootstrap/pmb/chroot/binfmt.py

65 lines
1.9 KiB
Python

# Copyright 2023 Oliver Smith
# SPDX-License-Identifier: GPL-3.0-or-later
import os
import logging
import pmb.helpers.run
import pmb.helpers.other
import pmb.parse
import pmb.parse.arch
def is_registered(arch_qemu):
return os.path.exists("/proc/sys/fs/binfmt_misc/qemu-" + arch_qemu)
def register(args, arch):
"""
Get arch, magic, mask.
"""
arch_qemu = pmb.parse.arch.alpine_to_qemu(arch)
# always make sure the qemu-<arch> binary is installed, since registering
# may happen outside of this method (e.g. by OS)
if f"qemu-{arch_qemu}" not in pmb.chroot.apk.installed(args):
pmb.chroot.apk.install(args, ["qemu-" + arch_qemu])
if is_registered(arch_qemu):
return
pmb.helpers.other.check_binfmt_misc(args)
# Don't continue if the actions from check_binfmt_misc caused the OS to
# automatically register the target arch
if is_registered(arch_qemu):
return
info = pmb.parse.binfmt_info(arch_qemu)
# Build registration string
# https://en.wikipedia.org/wiki/Binfmt_misc
# :name:type:offset:magic:mask:interpreter:flags
name = "qemu-" + arch_qemu
type = "M"
offset = ""
magic = info["magic"]
mask = info["mask"]
interpreter = "/usr/bin/qemu-" + arch_qemu + "-static"
flags = "C"
code = ":".join(["", name, type, offset, magic, mask, interpreter,
flags])
# Register in binfmt_misc
logging.info("Register qemu binfmt (" + arch_qemu + ")")
register = "/proc/sys/fs/binfmt_misc/register"
pmb.helpers.run.root(
args, ["sh", "-c", 'echo "' + code + '" > ' + register])
def unregister(args, arch):
arch_qemu = pmb.parse.arch.alpine_to_qemu(arch)
binfmt_file = "/proc/sys/fs/binfmt_misc/qemu-" + arch_qemu
if not os.path.exists(binfmt_file):
return
logging.info("Unregister qemu binfmt (" + arch_qemu + ")")
pmb.helpers.run.root(args, ["sh", "-c", "echo -1 > " + binfmt_file])