#!/bin/sh
#
# init — Linux guest init script for UTSM dual-kernel Linux compat layer.
#
# Boot sequence:
#   1. Mount essential filesystems
#   2. Load UTSM driver (built-in, /dev/utsm auto-created)
#   3. Start utsm_exec_daemon (background)
#   4. Daemon sends EXEC_READY, then HLT (park) → linux_launch() returns to UTSM
#   5. UTSM proceeds to load DSK; Linux guest stays parked until shell
#      invokes `linux <prog>` which triggers vmresume.
#
# The daemon runs forever, parking between requests. This init script
# should NOT exit (would panic the kernel); it sleeps indefinitely after
# starting the daemon so the kernel has a runnable init task.

PATH=/bin:/sbin:/usr/bin:/usr/sbin
export PATH

# Mount essential filesystems
mount -t proc none /proc 2>/dev/null
mount -t sysfs none /sys 2>/dev/null
mount -t devtmpfs none /dev 2>/dev/null

echo "[utsm-linux] init started"
echo "[utsm-linux] kernel: $(uname -r)"

# Verify /dev/utsm exists (driver is built-in, should be auto-created)
if [ ! -e /dev/utsm ]; then
    echo "[utsm-linux] WARNING: /dev/utsm not found — UTSM driver not loaded"
fi

# Start the exec daemon in the background.
# The daemon sends EXEC_READY then HLTs (parks the guest).
# UTSM's linux_launch() returns after this first HLT.
echo "[utsm-linux] starting utsm_exec_daemon..."
/bin/utsm_exec_daemon &
DAEMON_PID=$!
echo "[utsm-linux] daemon PID=$DAEMON_PID"

# init must not exit — sleep forever to keep the kernel happy.
# The daemon handles all UTSM exec requests; init just keeps the
# root task alive so the kernel doesn't panic.
echo "[utsm-linux] init: daemon running, entering idle hold"
while true; do
    sleep 3600
done