Orange Pi5 kernel

#!/usr/bin/env python
# SPDX-License-Identifier: GPL-2.0+
#
# This determines how many parallel tasks "make" is expecting, as it is
# not exposed via an special variables, reserves them all, runs a subprocess
# with PARALLELISM environment variable set, and releases the jobs back again.
#
# https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver
from __future__ import print_function
import os, sys, errno
import subprocess
 
# Extract and prepare jobserver file descriptors from envirnoment.
claim = 0
jobs = b""
try:
<------># Fetch the make environment options.
<------>flags = os.environ['MAKEFLAGS']
 
<------># Look for "--jobserver=R,W"
<------># Note that GNU Make has used --jobserver-fds and --jobserver-auth
<------># so this handles all of them.
<------>opts = [x for x in flags.split(" ") if x.startswith("--jobserver")]
 
<------># Parse out R,W file descriptor numbers and set them nonblocking.
<------>fds = opts[0].split("=", 1)[1]
<------>reader, writer = [int(x) for x in fds.split(",", 1)]
<------># Open a private copy of reader to avoid setting nonblocking
<------># on an unexpecting process with the same reader fd.
<------>reader = os.open("/proc/self/fd/%d" % (reader),
<------><------><------> os.O_RDONLY | os.O_NONBLOCK)
 
<------># Read out as many jobserver slots as possible.
<------>while True:
<------><------>try:
<------><------><------>slot = os.read(reader, 8)
<------><------><------>jobs += slot
<------><------>except (OSError, IOError) as e:
<------><------><------>if e.errno == errno.EWOULDBLOCK:
<------><------><------><------># Stop at the end of the jobserver queue.
<------><------><------><------>break
<------><------><------># If something went wrong, give back the jobs.
<------><------><------>if len(jobs):
<------><------><------><------>os.write(writer, jobs)
<------><------><------>raise e
<------># Add a bump for our caller's reserveration, since we're just going
<------># to sit here blocked on our child.
<------>claim = len(jobs) + 1
except (KeyError, IndexError, ValueError, OSError, IOError) as e:
<------># Any missing environment strings or bad fds should result in just
<------># not being parallel.
<------>pass
 
# We can only claim parallelism if there was a jobserver (i.e. a top-level
# "-jN" argument) and there were no other failures. Otherwise leave out the
# environment variable and let the child figure out what is best.
if claim > 0:
<------>os.environ['PARALLELISM'] = '%d' % (claim)
 
rc = subprocess.call(sys.argv[1:])
 
# Return all the reserved slots.
if len(jobs):
<------>os.write(writer, jobs)
 
sys.exit(rc)