feat: add support for custom user and workdir in init

skel/sbin/init

@@ -9,44 +9,43 @@ busybox mount -t tmpfs tmpfs /dev/shm -o nosuid,nodev,mode=1777
 
 # net
 [ -f /etc/hostname ] && busybox hostname -F /etc/hostname
-busybox ifconfig lo up
+[ -z "$noloopback" ] && busybox ifconfig lo up
 
-# custom init
-if [ -f /proc/device-tree/cartesi/init ]; then
-    . /proc/device-tree/cartesi/init
-fi
+# source environment
+[ -f /etc/environment ] && . /etc/environment
+export PATH="$PATH:/opt/cartesi/bin"
+
+# execute init from device tree
+[ -f /proc/device-tree/cartesi/init ] && . /proc/device-tree/cartesi/init
 
-# use entrypoint from device tree when available
+# set entrypoint from device tree when available
 if [ -s /proc/device-tree/cartesi/entrypoint ]; then
     ENTRYPOINT=". /proc/device-tree/cartesi/entrypoint"
-else
+elif [ -n "$*" ]; then
     ENTRYPOINT="$*"
 fi
 
 # execute entrypoint
 if [ -n "$ENTRYPOINT" ]; then
-    [ -f /etc/environment ] && . /etc/environment
-    export PATH="/opt/cartesi/bin:$PATH"
-
-    # can login as dapp user?
-    if [ ! "$single" == "yes" ] && busybox id dapp &> /dev/null; then
-        if [ -c /dev/rollup ]; then
-            busybox chown root:dapp /dev/rollup
-            busybox chmod 660 /dev/rollup
-        fi
-        if [ -c /dev/yield ]; then
-            busybox chown root:dapp /dev/yield
-            busybox chmod 660 /dev/yield
-        fi
-        export HOME=~dapp USER=dapp LOGNAME=dapp
-    else
-        export HOME=~root USER=root LOGNAME=root
+    # set user
+    if [ -z "$USER" ]; then
+        busybox id dapp &> /dev/null && USER=dapp || USER=root
     fi
 
-    cd $HOME &&
+    # give user group access to rollup and yield devices
+    [ -c /dev/rollup ] && \
+        busybox chown :$(busybox id -g $USER) /dev/rollup && \
+        busybox chmod g+rw /dev/rollup
+    [ -c /dev/yield ] &&
+        busybox chown :$(busybox id -g $USER) /dev/yield && \
+        busybox chmod g+rw /dev/yield
+
+    # finally execute
+    (export USER LOGNAME=$USER HOME="$(eval echo ~$USER)"; \
+        cd ${WORKDIR:-"$HOME"} && \
         busybox setsid \
         busybox cttyhack \
-        busybox su -p $USER -c "$ENTRYPOINT"
+        busybox su -p $USER -c "$ENTRYPOINT")
 else
     echo "Nothing to do."
 fi
@@ -55,15 +54,18 @@ busybox mount -o ro,remount /
 busybox umount -af
 busybox poweroff -f
 
-# Copyright 2023 Cartesi Pte. Ltd.
+# Copyright Cartesi and individual authors (see AUTHORS)
+# SPDX-License-Identifier: LGPL-3.0-or-later
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
 #
-# Licensed under the Apache License, Version 2.0 (the "License"); you may not
-# use this file except in compliance with the License. You may obtain a copy of
-# the License at http://www.apache.org/licenses/LICENSE-2.0
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE. See the GNU General Public License for more details.
 #
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations under
-# the License.
+# You should have received a copy of the GNU General Public License along with
+# this program (see COPYING). If not, see <https://www.gnu.org/licenses/>.
 #