--- ../initramfs-modem1/root/bin/modem-up	2026-09-30 04:09:50.125889992 +0600
+++ root/bin/modem-up	2026-09-30 04:28:18.531492310 +0600
@@ -8,8 +8,8 @@
 grep -q " /firmware .* ro," /proc/mounts || { echo "ABORT: /firmware not mounted ro"; exit 1; }
 [ "$(cat /sys/module/firmware_class/parameters/path)" = /firmware/image ] || { echo "ABORT: firmware path"; exit 1; }
 echo "[modem-up] before:"; for r in /sys/class/remoteproc/remoteproc*; do echo "$r $(cat $r/name) $(cat $r/state) $(cat $r/firmware)"; done
-echo "[modem-up] starting: rmtfs -r -P -s -v"
-rmtfs -r -P -s -v > /tmp/rmtfs.log 2>&1 &
+echo "[modem-up] starting: LD_PRELOAD=/usr/lib/linebuf.so rmtfs -r -P -s -v"
+LD_PRELOAD=/usr/lib/linebuf.so rmtfs -r -P -s -v > /tmp/rmtfs.log 2>&1 &	# linebuf.so = stdbuf -oL equivalent (logging only)
 echo $! > /tmp/rmtfs.pid
 sleep 20
 echo "[modem-up] after 20s:"; for r in /sys/class/remoteproc/remoteproc*; do echo "$r $(cat $r/name) $(cat $r/state)"; done