Factor out chroot helpers to lib.sh
This commit removes all of the chroot refactor to a seperate file. This paves the way to use these functions in all other scripts.
This commit is contained in:
Michael Aldridge
parent
10568660ac
commit
34bffe1e2a
|
|
@ -0,0 +1,189 @@
|
|||
info_msg() {
|
||||
# This function handles the printing that is bold within all
|
||||
# scripts. This is a convenience function so that the rather ugly
|
||||
# looking ASCII escape codes live in only one place.
|
||||
printf "\033[1m%s\n\033[m" "$@"
|
||||
}
|
||||
|
||||
die() {
|
||||
# This function is registered in all the scripts to make sure that
|
||||
# the important mounts get cleaned up and the $ROOTFS location is
|
||||
# removed.
|
||||
printf "FATAL: %s\n" "$@"
|
||||
umount_pseudofs
|
||||
[ -d "$ROOTFS" ] && rm -rf "$ROOTFS"
|
||||
exit 1
|
||||
}
|
||||
|
||||
mount_pseudofs() {
|
||||
# This function ensures that the psuedofs mountpoints are present
|
||||
# in the chroot. Strictly they are not necessary to have for many
|
||||
# commands, but bind-mounts are cheap and it isn't too bad to just
|
||||
# mount them all the time.
|
||||
for f in dev proc sys; do
|
||||
# In a naked chroot there is nothing to bind the mounts to, so
|
||||
# we need to create directories for these first.
|
||||
[ ! -d "$ROOTFS/$f" ] && mkdir -p "$ROOTFS/$f"
|
||||
if ! mountpoint -q "$ROOTFS/$f" ; then
|
||||
# It is VERY important that this only happen if the
|
||||
# pseudofs isn't already mounted. If it already is then
|
||||
# this is virtually impossible to troubleshoot because it
|
||||
# looks like the subsequent umount just isn't working.
|
||||
mount -r --bind /$f "$ROOTFS/$f"
|
||||
fi
|
||||
done
|
||||
}
|
||||
|
||||
umount_pseudofs() {
|
||||
# This function cleans up the mounts in the chroot. Failure to
|
||||
# clean up these mounts will prevent the tmpdir from being
|
||||
# deletable instead throwing the error "Device or Resource Busy".
|
||||
# The '-f' option is passed to umount to account for the
|
||||
# contingency where the psuedofs mounts are not present.
|
||||
if [ -d "${ROOTFS}" ]; then
|
||||
for f in dev proc sys; do
|
||||
umount -f "$ROOTFS/$f" >/dev/null 2>&1
|
||||
done
|
||||
fi
|
||||
}
|
||||
|
||||
run_cmd_target() {
|
||||
info_msg "Running $* for target $XBPS_TARGET_ARCH ..."
|
||||
if [ "$XBPS_TARGET_ARCH" = "$(xbps-uhelper arch)" ] ; then
|
||||
# This is being run on the same architecture as the host,
|
||||
# therefore we should set XBPS_ARCH.
|
||||
if ! eval XBPS_ARCH="$XBPS_TARGET_ARCH" "$@" ; then
|
||||
die "Could not run command $*"
|
||||
fi
|
||||
else
|
||||
# This is being run on a foriegn arch, therefore we should set
|
||||
# XBPS_TARGET_ARCH. In this case XBPS will not attempt
|
||||
# certain actions and will require reconfiguration later.
|
||||
if ! eval XBPS_TARGET_ARCH="$XBPS_TARGET_ARCH" "$@" ; then
|
||||
die "Could not run command $*"
|
||||
fi
|
||||
fi
|
||||
}
|
||||
|
||||
run_cmd() {
|
||||
# This is a general purpose function to run commands that a user
|
||||
# may wish to see. For example its useful to see the tar/xz
|
||||
# pipeline to not need to delve into the scripts to see what
|
||||
# options its set up with.
|
||||
info_msg "Running $*"
|
||||
eval "$@"
|
||||
}
|
||||
|
||||
run_cmd_chroot() {
|
||||
# General purpose chroot function which makes sure the chroot is
|
||||
# prepared. This function takes 2 arguments, the location to
|
||||
# chroot to and the command to run.
|
||||
|
||||
# This is an idempotent function, it is safe to call every time
|
||||
# before entering the chroot. This has the advantage of making
|
||||
# execution in the chroot appear as though it "Just Works(tm)".
|
||||
register_binfmt
|
||||
|
||||
# Before we step into the chroot we need to make sure the
|
||||
# pseudo-filesystems are ready to go. Not all commands will need
|
||||
# this, but its still a good idea to call it here anyway.
|
||||
mount_pseudofs
|
||||
|
||||
# With assurance that things will run now we can jump into the
|
||||
# chroot and run stuff!
|
||||
chroot "$1" sh -c "$2"
|
||||
}
|
||||
|
||||
cleanup_chroot() {
|
||||
# This function cleans up the chroot shims that are used by QEMU
|
||||
# to allow builds on alien platforms. It takes no arguments but
|
||||
# expects the global $ROOTFS variable to be set.
|
||||
|
||||
# Un-Mount the pseudofs mounts if they were mounted
|
||||
umount_pseudofs
|
||||
|
||||
# If a QEMU binary was copied in, remove that as well
|
||||
if [ -x "$ROOTFS/usr/bin/$QEMU_BIN" ] ; then
|
||||
rm "$ROOTFS/usr/bin/$QEMU_BIN"
|
||||
fi
|
||||
}
|
||||
|
||||
# TODO: Figure out how to register the binfmt for x86_64 and for i686
|
||||
# to facilitate building on alien build systems.
|
||||
register_binfmt() {
|
||||
# This function sets up everything that is needed to be able to
|
||||
# chroot into a ROOTFS and be able to run commands there. This
|
||||
# really matters on platforms where the host architecture is
|
||||
# different from the target, and you wouldn't be able to run
|
||||
# things like xbps-reconfigure -a. This function is idempotent
|
||||
# (You can run it multiple times without modifying state). This
|
||||
# function takes no arguments, but does expect the global variable
|
||||
# $XBPS_TARGET_ARCH to be set.
|
||||
|
||||
# This select sets up the "magic" bytes in /proc that let the
|
||||
# kernel select an alternate interpreter. More values for this
|
||||
# map can be obtained from here:
|
||||
# https://github.com/qemu/qemu/blob/master/scripts/qemu-binfmt-conf.sh
|
||||
case "${XBPS_TARGET_ARCH}" in
|
||||
armv*)
|
||||
_cpu=arm
|
||||
_magic="\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00"
|
||||
_mask="\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff"
|
||||
QEMU_BIN=qemu-arm-static
|
||||
;;
|
||||
aarch64*)
|
||||
_cpu=aarch64
|
||||
_magic="\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\xb7"
|
||||
_mask="\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff"
|
||||
QEMU_BIN=qemu-aarch64-static
|
||||
;;
|
||||
mipsel*)
|
||||
_cpu=mipsel
|
||||
_magic="\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08\x00"
|
||||
_mask="\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff"
|
||||
QEMU_BIN=qemu-mipsel-static
|
||||
;;
|
||||
*86*)
|
||||
info_msg "FIXME: Assuming that x86 instructions are native"
|
||||
QEMU_BIN=NATIVE
|
||||
;;
|
||||
*)
|
||||
die "Unknown target architecture!"
|
||||
;;
|
||||
esac
|
||||
|
||||
# In the special case where the build is native we can return
|
||||
# without doing anything else
|
||||
if [ "$QEMU_BIN" = "NATIVE" ] ; then
|
||||
return
|
||||
fi
|
||||
|
||||
# For builds that do not match the host architecture, the correct
|
||||
# qemu binary will be required.
|
||||
if ! $QEMU_BIN -version >/dev/null 2>&1; then
|
||||
die "$QEMU_BIN binary is missing in your system, exiting."
|
||||
fi
|
||||
|
||||
# In order to use the binfmt system the binfmt_misc mountpoint
|
||||
# must exist inside of proc
|
||||
if ! mountpoint -q /proc/sys/fs/binfmt_misc ; then
|
||||
modprobe -q binfmt_misc
|
||||
mount -t binfmt_misc binfmt_misc /proc/sys/fs/binfmt_misc 2>/dev/null
|
||||
fi
|
||||
|
||||
# Only register if the map is incomplete
|
||||
if [ ! -f /proc/sys/fs/binfmt_misc/qemu-$_cpu ] ; then
|
||||
echo ":qemu-$_cpu:M::$_magic:$_mask:$QEMU_BIN:" > /proc/sys/fs/binfmt_misc/register 2>/dev/null
|
||||
fi
|
||||
|
||||
# If the static binary isn't in the chroot then the chroot will
|
||||
# fail. The kernel knows about the map but without the static
|
||||
# version there's no interpreter in the chroot, only the
|
||||
# dynamically linked one in the host. To simplify things we just
|
||||
# use the static one always and make sure it shows up at the same
|
||||
# place in the host and the chroot.
|
||||
if [ ! -x "$ROOTFS/usr/bin/$QEMU_BIN" ] ; then
|
||||
cp -f "$(which "$QEMU_BIN")" "$ROOTFS/usr/bin" ||
|
||||
die "Could not install $QEMU_BIN to $ROOTFS/usr/bin/"
|
||||
fi
|
||||
}
|
||||
198
mkrootfs.sh.in
198
mkrootfs.sh.in
|
|
@ -28,21 +28,17 @@
|
|||
readonly PROGNAME=$(basename "$0")
|
||||
readonly ARCH=$(uname -m)
|
||||
|
||||
# This source pulls in all the functions from lib.sh. This set of
|
||||
# functions makes it much easier to work with chroots and abstracts
|
||||
# away all the problems with running binaries with QEMU.
|
||||
# shellcheck source=./lib.sh
|
||||
. ./lib.sh
|
||||
|
||||
# Die is a function provided in lib.sh which handles the cleanup of
|
||||
# the mounts and removal of temporary directories if the running
|
||||
# program exists unexpectedly.
|
||||
trap 'die "Interrupted! exiting..."' INT TERM HUP
|
||||
|
||||
|
||||
info_msg() {
|
||||
printf "\033[1m%s\n\033[m" "$@"
|
||||
}
|
||||
|
||||
die() {
|
||||
printf "FATAL: %s\n" "$@"
|
||||
umount_pseudofs
|
||||
[ -d "$ROOTFS" ] && rm -rf "$ROOTFS"
|
||||
exit 1
|
||||
}
|
||||
|
||||
|
||||
# Even though we only support really one target for most of these
|
||||
# architectures this lets us refer to these quickly and easily by
|
||||
# XBPS_ARCH. This makes it a lot more obvious what is happening later
|
||||
|
|
@ -68,178 +64,12 @@ Options
|
|||
_EOF
|
||||
}
|
||||
|
||||
mount_pseudofs() {
|
||||
# This function ensures that the psuedofs mountpoints are present
|
||||
# in the chroot. Strictly they are not necessary to have for many
|
||||
# commands, but bind-mounts are cheap and it isn't too bad to just
|
||||
# mount them all the time.
|
||||
for f in dev proc sys; do
|
||||
# In a naked chroot there is nothing to bind the mounts to, so
|
||||
# we need to create directories for these first.
|
||||
[ ! -d "$ROOTFS/$f" ] && mkdir -p "$ROOTFS/$f"
|
||||
if ! mountpoint -q "$ROOTFS/$f" ; then
|
||||
# It is VERY important that this only happen if the
|
||||
# pseudofs isn't already mounted. If it already is then
|
||||
# this is virtually impossible to troubleshoot because it
|
||||
# looks like the subsequent umount just isn't working.
|
||||
mount -r --bind /$f "$ROOTFS/$f"
|
||||
fi
|
||||
done
|
||||
}
|
||||
# ########################################
|
||||
# SCRIPT EXECUTION STARTS HERE
|
||||
# ########################################
|
||||
|
||||
umount_pseudofs() {
|
||||
# This function cleans up the mounts in the chroot. Failure to
|
||||
# clean up these mounts will prevent the tmpdir from being
|
||||
# deletable instead throwing the error "Device or Resource Busy".
|
||||
# The '-f' option is passed to umount to account for the
|
||||
# contingency where the psuedofs mounts are not present.
|
||||
if [ -d "${ROOTFS}" ]; then
|
||||
for f in dev proc sys; do
|
||||
umount -f "$ROOTFS/$f" >/dev/null 2>&1
|
||||
done
|
||||
fi
|
||||
}
|
||||
|
||||
run_cmd_target() {
|
||||
info_msg "Running $* for target $XBPS_TARGET_ARCH ..."
|
||||
if [ "$XBPS_TARGET_ARCH" = "$(xbps-uhelper arch)" ] ; then
|
||||
# This is being run on the same architecture as the host,
|
||||
# therefore we should set XBPS_ARCH.
|
||||
if ! eval XBPS_ARCH="$XBPS_TARGET_ARCH" "$@" ; then
|
||||
die "Could not run command $*"
|
||||
fi
|
||||
else
|
||||
# This is being run on a foriegn arch, therefore we should set
|
||||
# XBPS_TARGET_ARCH. In this case XBPS will not attempt
|
||||
# certain actions and will require reconfiguration later.
|
||||
if ! eval XBPS_TARGET_ARCH="$XBPS_TARGET_ARCH" "$@" ; then
|
||||
die "Could not run command $*"
|
||||
fi
|
||||
fi
|
||||
}
|
||||
|
||||
run_cmd() {
|
||||
info_msg "Running $*"
|
||||
eval "$@"
|
||||
}
|
||||
|
||||
run_cmd_chroot() {
|
||||
# General purpose chroot function which makes sure the chroot is
|
||||
# prepared. This function takes 2 arguments, the location to
|
||||
# chroot to and the command to run.
|
||||
|
||||
# This is an idempotent function, it is safe to call every time
|
||||
# before entering the chroot. This has the advantage of making
|
||||
# execution in the chroot appear as though it "Just Works(tm)".
|
||||
register_binfmt
|
||||
|
||||
# Before we step into the chroot we need to make sure the
|
||||
# pseudo-filesystems are ready to go. Not all commands will need
|
||||
# this, but its still a good idea to call it here anyway.
|
||||
mount_pseudofs
|
||||
|
||||
# With assurance that things will run now we can jump into the
|
||||
# chroot and run stuff!
|
||||
chroot "$1" sh -c "$2"
|
||||
}
|
||||
|
||||
cleanup_chroot() {
|
||||
# This function cleans up the chroot shims that are used by QEMU
|
||||
# to allow builds on alien platforms. It takes no arguments but
|
||||
# expects the global $ROOTFS variable to be set.
|
||||
|
||||
# Un-Mount the pseudofs mounts if they were mounted
|
||||
umount_pseudofs
|
||||
|
||||
# If a QEMU binary was copied in, remove that as well
|
||||
if [ -x "$ROOTFS/usr/bin/$QEMU_BIN" ] ; then
|
||||
rm "$ROOTFS/usr/bin/$QEMU_BIN"
|
||||
fi
|
||||
}
|
||||
|
||||
# TODO: Figure out how to register the binfmt for x86_64 and for i686
|
||||
# to facilitate building on alien build systems.
|
||||
register_binfmt() {
|
||||
# This function sets up everything that is needed to be able to
|
||||
# chroot into a ROOTFS and be able to run commands there. This
|
||||
# really matters on platforms where the host architecture is
|
||||
# different from the target, and you wouldn't be able to run
|
||||
# things like xbps-reconfigure -a. This function is idempotent
|
||||
# (You can run it multiple times without modifying state). This
|
||||
# function takes no arguments, but does expect the global variable
|
||||
# $XBPS_TARGET_ARCH to be set.
|
||||
|
||||
# This select sets up the "magic" bytes in /proc that let the
|
||||
# kernel select an alternate interpreter. More values for this
|
||||
# map can be obtained from here:
|
||||
# https://github.com/qemu/qemu/blob/master/scripts/qemu-binfmt-conf.sh
|
||||
case "${XBPS_TARGET_ARCH}" in
|
||||
armv*)
|
||||
_cpu=arm
|
||||
_magic="\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00"
|
||||
_mask="\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff"
|
||||
QEMU_BIN=qemu-arm-static
|
||||
;;
|
||||
aarch64*)
|
||||
_cpu=aarch64
|
||||
_magic="\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\xb7"
|
||||
_mask="\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff"
|
||||
QEMU_BIN=qemu-aarch64-static
|
||||
;;
|
||||
mipsel*)
|
||||
_cpu=mipsel
|
||||
_magic="\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08\x00"
|
||||
_mask="\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff"
|
||||
QEMU_BIN=qemu-mipsel-static
|
||||
;;
|
||||
*86*)
|
||||
info_msg "FIXME: Assuming that x86 instructions are native"
|
||||
QEMU_BIN=NATIVE
|
||||
;;
|
||||
*)
|
||||
die "Unknown target architecture!"
|
||||
;;
|
||||
esac
|
||||
|
||||
# In the special case where the build is native we can return
|
||||
# without doing anything else
|
||||
if [ "$QEMU_BIN" = "NATIVE" ] ; then
|
||||
return
|
||||
fi
|
||||
|
||||
# For builds that do not match the host architecture, the correct
|
||||
# qemu binary will be required.
|
||||
if ! $QEMU_BIN -version >/dev/null 2>&1; then
|
||||
die "$QEMU_BIN binary is missing in your system, exiting."
|
||||
fi
|
||||
|
||||
# In order to use the binfmt system the binfmt_misc mountpoint
|
||||
# must exist inside of proc
|
||||
if ! mountpoint -q /proc/sys/fs/binfmt_misc ; then
|
||||
modprobe -q binfmt_misc
|
||||
mount -t binfmt_misc binfmt_misc /proc/sys/fs/binfmt_misc 2>/dev/null
|
||||
fi
|
||||
|
||||
# Only register if the map is incomplete
|
||||
if [ ! -f /proc/sys/fs/binfmt_misc/qemu-$_cpu ] ; then
|
||||
echo ":qemu-$_cpu:M::$_magic:$_mask:$QEMU_BIN:" > /proc/sys/fs/binfmt_misc/register 2>/dev/null
|
||||
fi
|
||||
|
||||
# If the static binary isn't in the chroot then the chroot will
|
||||
# fail. The kernel knows about the map but without the static
|
||||
# version there's no interpreter in the chroot, only the
|
||||
# dynamically linked one in the host. To simplify things we just
|
||||
# use the static one always and make sure it shows up at the same
|
||||
# place in the host and the chroot.
|
||||
if [ ! -x "$ROOTFS/usr/bin/$QEMU_BIN" ] ; then
|
||||
cp -f "$(which "$QEMU_BIN")" "$ROOTFS/usr/bin" ||
|
||||
die "Could not install $QEMU_BIN to $ROOTFS/usr/bin/"
|
||||
fi
|
||||
}
|
||||
|
||||
#
|
||||
# main()
|
||||
#
|
||||
# Boilerplate option parsing. This script supports the bare minimum
|
||||
# needed to build an image.
|
||||
while getopts "C:c:h:r:V" opt; do
|
||||
case $opt in
|
||||
C) XBPS_CONFFILE="-C $OPTARG";;
|
||||
|
|
|
|||
Loading…
Reference in New Issue