From bafa91b945ac77e2e1d000e356ca819bd5f87460 Mon Sep 17 00:00:00 2001 From: Christian Poessinger Date: Mon, 8 Jun 2020 22:45:04 +0200 Subject: console: T2529: migrate from ttyUSB device to new device in /dev/serial/by-bus During testing it was discovered that there is a well known problem (we had for ethernet interfaces) also in the serial port world. They will be enumerated and mapped to /dev/ttyUSBxxx differently from boot to boot. This is especially painful on my development APU4 board which also has a Sierra Wireless MC7710 LTE module installed. The serial port will toggle between ttyUSB2 and ttyUSB5 depending on the amount of serial port extenders attached (FT4232H). The shipped udev rule (/usr/lib/udev/rules.d/60-serial.rules) partly solves this by enumerating the devices into /dev/serial/by-id folder with their name and serial number - it's a very good idea but I've found that not all of the FT4232H dongles have a serial number programmed - this leads to the situation that when you plug in two cables with both having serial number 0 - only one device symlink will appear - the previous one is always overwritten by the latter one. Derive /usr/lib/udev/rules.d/60-serial.rules and create a /dev/serial/by-bus directory and group devices by attached USB root port. --- data/templates/getty/serial-getty.service.tmpl | 37 ++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 data/templates/getty/serial-getty.service.tmpl (limited to 'data/templates') diff --git a/data/templates/getty/serial-getty.service.tmpl b/data/templates/getty/serial-getty.service.tmpl new file mode 100644 index 000000000..0183eae7d --- /dev/null +++ b/data/templates/getty/serial-getty.service.tmpl @@ -0,0 +1,37 @@ +[Unit] +Description=Serial Getty on %I +Documentation=man:agetty(8) man:systemd-getty-generator(8) +Documentation=http://0pointer.de/blog/projects/serial-console.html +BindsTo=dev-%i.device +After=dev-%i.device systemd-user-sessions.service plymouth-quit-wait.service getty-pre.target +After=vyos-router.service + +# If additional gettys are spawned during boot then we should make +# sure that this is synchronized before getty.target, even though +# getty.target didn't actually pull it in. +Before=getty.target +IgnoreOnIsolate=yes + +# IgnoreOnIsolate causes issues with sulogin, if someone isolates +# rescue.target or starts rescue.service from multi-user.target or +# graphical.target. +Conflicts=rescue.service +Before=rescue.service + +[Service] +# The '-o' option value tells agetty to replace 'login' arguments with an +# option to preserve environment (-p), followed by '--' for safety, and then +# the entered username. +ExecStart=-/sbin/agetty -o '-p -- \\u' --keep-baud {{ speed }} %I $TERM +Type=idle +Restart=always +UtmpIdentifier=%I +TTYPath=/dev/%I +TTYReset=yes +TTYVHangup=yes +KillMode=process +IgnoreSIGPIPE=no +SendSIGHUP=yes + +[Install] +WantedBy=getty.target -- cgit v1.2.3