Add envkernel.sh: instant mainlining environment (#1424)

Changes:
* `helpers/envkernel.sh`:
  * installs everything needed for kernel compilation in the native
    chroot
  * mounts the kernel source to `/mnt/linux` inside the chroot
  * creates `/mnt/linux/.output` and chowns it to the `pmos` user, that
    folder will be used for the kernel build output
  * sets up aliases for `make`, `pmbootstrap`, `pmbroot`, `kernelroot`
* new action `pmbootstrap work_migrate`: does the interactive work
  folder migration if necessary, otherwise it doesn't output anything
  * when calling this first, we can safely use all other commands
    non-interactively without showing the output

Benefits:
* Fast setup (especially for people who are new to kernel
  compilation
  * No need to figure out distribution specific package names
    (cross compilers!)
  * No need to do a test build just to verify that the right
    packages are installed
* Less error prone
  * The right dependencies are always installed
  * `ARCH` and `CROSS_COMPILE` variables always get set automatically
    and based on `deviceinfo_arch`
  * If the build environment is broken for some reason, just zap and
    start over
* Easy to reproduce problems

Notes:
* `make menuconfig` works as well
* Sourcing was tested with `zsh`, `bash` and `fish`, it should be easy to
  extend for other shells

helpers/envkernel.fish

@@ -0,0 +1,17 @@
+#!/usr/bin/env fish
+# Copyright 2018 Oliver Smith
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# Fish compatibility code from envkernel.sh
+set script_dir (dirname (status filename))
+sh "$script_dir/envkernel.sh" --fish 1>| read -z fishcode
+
+# Verbose output
+if [ "$argv" = "-v" ]
+	echo "(eval code start)"
+	printf "$fishcode"
+	echo "(eval code end)"
+end
+
+# Execute generated code
+echo -e "$fishcode" | source -

helpers/envkernel.sh

@@ -0,0 +1,183 @@
+#!/bin/sh
+# Copyright 2018 Oliver Smith
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+# usage example:
+# $ cd ~/code/linux
+# $ source ~/code/pmbootstrap/helpers/envkernel.sh
+
+check_kernel_folder() {
+	[ -e "Kbuild" ] && return
+	echo "ERROR: This folder is not a linux source tree: $PWD"
+	return 1
+}
+
+
+export_pmbootstrap_dir() {
+	# Get pmbootstrap dir based on this script's location
+	# See also: <https://stackoverflow.com/a/29835459>
+	# shellcheck disable=SC2039
+	if [ -n "${BASH_SOURCE[0]}" ]; then
+		script_dir="$(dirname "${BASH_SOURCE[0]}")"
+	else
+		script_dir="$(dirname "$1")"
+	fi
+
+	# Fail with debug information
+	# shellcheck disable=SC2155
+	export pmbootstrap_dir=$(realpath "$script_dir/..")
+	if ! [ -e "$pmbootstrap_dir/pmbootstrap.py" ]; then
+		echo "ERROR: Failed to get the script's location with your shell."
+		echo "Please adjust export_pmbootstrap_dir in envkernel.sh. Debug info:"
+		echo "\$1: $1"
+		echo "\$pmbootstrap_dir: $pmbootstrap_dir"
+		return 1
+	fi
+}
+
+
+set_alias_pmbootstrap() {
+	pmbootstrap="$pmbootstrap_dir"/pmbootstrap.py
+	# shellcheck disable=SC2139
+	alias pmbootstrap="$pmbootstrap"
+	if [ -e ~/.config/pmbootstrap.cfg ]; then
+		$pmbootstrap work_migrate
+	else
+		echo "NOTE: First run of pmbootstrap, running 'pmbootstrap init'"
+		$pmbootstrap init
+	fi
+}
+
+
+export_chroot_device_deviceinfo() {
+	chroot="$(pmbootstrap config work)/chroot_native"
+	device="$(pmbootstrap config device)"
+	deviceinfo="$pmbootstrap_dir/aports/device/device-$device/deviceinfo"
+	export chroot device deviceinfo
+}
+
+
+check_device() {
+	[ -e "$deviceinfo" ] && return
+	echo "ERROR: Please select a valid device in 'pmbootstrap init'"
+	return 1
+}
+
+
+initialize_chroot() {
+	# Don't initialize twice
+	flag="$chroot/tmp/envkernel/setup_done"
+	[ -e "$flag" ] && return
+
+	# Install needed packages
+	echo "Initializing Alpine chroot (details: 'pmbootstrap log')"
+	# shellcheck disable=SC2154
+	pmbootstrap -q chroot -- apk -q add \
+		abuild \
+		bc \
+		binutils-"$deviceinfo_arch" \
+		binutils \
+		bison \
+		flex \
+		gcc-"$deviceinfo_arch" \
+		gcc \
+		linux-headers \
+		libressl-dev \
+		make \
+		musl-dev \
+		ncurses-dev \
+		perl || return 1
+
+	# Create /mnt/linux
+	sudo mkdir -p "$chroot/mnt/linux"
+
+	# Mark as initialized
+	mkdir -p "$chroot/tmp/envkernel"
+	touch "$flag"
+}
+
+
+mount_kernel_source() {
+	[ -e "$chroot/mnt/linux/Kbuild" ] && return
+	sudo mount --bind "$PWD" "$chroot/mnt/linux"
+}
+
+
+create_output_folder() {
+	[ -d "$chroot/mnt/linux/.output" ] && return
+	mkdir -p ".output"
+	pmbootstrap -q chroot -- chown -R pmos:pmos "/mnt/linux/.output"
+}
+
+
+set_alias_make() {
+	# Cross compiler prefix
+	# shellcheck disable=SC1090
+	prefix="$(. "$chroot/usr/share/abuild/functions.sh";
+		arch_to_hostspec "$deviceinfo_arch")"
+
+	# Kernel architecture
+	case "$deviceinfo_arch" in
+		aarch64*) arch="arm64" ;;
+		arm*) arch="arm" ;;
+	esac
+
+	# Build make command
+	cmd="echo '*** pmbootstrap envkernel.sh active for $PWD! ***';"
+	cmd="$cmd pmbootstrap -q chroot --"
+	cmd="$cmd ARCH=$arch"
+	cmd="$cmd CROSS_COMPILE=/usr/bin/$prefix-"
+	cmd="$cmd make -C /mnt/linux O=/mnt/linux/.output"
+	# shellcheck disable=SC2139
+	alias make="$cmd"
+}
+
+
+set_alias_pmbroot_kernelroot() {
+	# shellcheck disable=SC2139
+	alias pmbroot="cd '$pmbootstrap_dir'"
+	# shellcheck disable=SC2139
+	alias kernelroot="cd '$PWD'"
+}
+
+main() {
+	# Stop executing once a function fails
+	# shellcheck disable=SC1090
+	if check_kernel_folder \
+		&& export_pmbootstrap_dir "$1" \
+		&& set_alias_pmbootstrap \
+		&& export_chroot_device_deviceinfo \
+		&& check_device \
+		&& . "$deviceinfo" \
+		&& initialize_chroot \
+		&& mount_kernel_source \
+		&& create_output_folder \
+		&& set_alias_make \
+		&& set_alias_pmbroot_kernelroot; then
+
+		# Success
+		echo "pmbootstrap envkernel.sh activated successfully."
+		echo " * kernel source:  $PWD"
+		echo " * output folder:  $PWD/.output"
+		echo " * architecture:   $arch ($device is $deviceinfo_arch)"
+		echo " * aliases: make, kernelroot, pmbootstrap, pmbroot" \
+			"(see 'type make' etc.)"
+	else
+		# Failure
+		echo "See also: <https://postmarketos.org/troubleshooting>"
+		return 1
+	fi
+}
+
+
+# Print fish alias syntax (when called from envkernel.fish)
+fish_compat() {
+	[ "$1" = "--fish" ] || return
+	for name in make kernelroot pmbootstrap pmbroot; do
+		echo "alias $(alias $name | sed 's/=/ /')"
+	done
+}
+
+# Run main() with all output redirected to stderr
+# Afterwards print fish compatible syntax to stdout
+main "$0" >&2 && fish_compat "$1"

pmb/helpers/frontend.py

@@ -317,6 +317,11 @@ def stats(args):
     pmb.chroot.user(args, ["ccache", "-s"], suffix, log=False)
 
 
+def work_migrate(args):
+    # do nothing (pmb/__init__.py already did the migration)
+    pmb.helpers.logging.disable()
+
+
 def log(args):
     if args.clear_log:
         pmb.helpers.run.user(args, ["truncate", "-s", "0", args.log],

pmb/parse/arguments.py

@@ -240,6 +240,9 @@ def arguments():
     sub.add_parser("shutdown", help="umount, unregister binfmt")
     sub.add_parser("index", help="re-index all repositories with custom built"
                    " packages (do this after manually removing package files)")
+    sub.add_parser("work_migrate", help="run this before using pmbootstrap"
+                                        " non-interactively to migrate the"
+                                        " work folder version on demand")
     arguments_export(sub)
     arguments_flasher(sub)
     arguments_initfs(sub)

test/static_code_analysis.sh

@@ -45,6 +45,7 @@ sh_files="
 	./aports/main/mdss-fb-init-hack/mdss-fb-init-hack.sh
 	./aports/main/postmarketos-ui-hildon/postmarketos-ui-hildon.post-install
 	./helpers/envsetup.sh
+	./helpers/envkernel.sh
 	$(find . -path './aports/main/postmarketos-ui-hildon/*.sh')
 	$(find . -name '*.trigger')
 	$(find . -path './aports/main/devicepkg-dev/*.sh')