Subject: util-linux: prevent agetty from exiting if a serial port doesn't exist

From: Gregory Nowak <[email-masked]>
Date: Wed, 24 May 2017 20:16:16 -0700

Package: util-linux
Version: 2.26.2-6+devuan1
Severity: wishlist

Dear Maintainer,
Please consider adding the ability for agetty/getty to keep running if attached to a serial port that doesn't exist, perhaps by passing a flag to it at invokation. This request is related to:
<https://git.devuan.org/sdk/arm-sdk/issues/4>
If agetty/getty was passed for example a --no-terminate flag, and attached to a valid serial port, it should behave like it does now. If getty/agetty was passed the --no-terminate flag for example, and attached to a serial port which doesn't exist, it would keep running instead of terminating. The agetty/getty instance doesn't need to check if that serial port becomes active later, The user would respawn agetty/getty via init if he/she wanted to use it on a serial port which wasn't active previously, but which later became active.

This functionality would make it possible to have agetty listening on /dev/ttyS0 on the raspberry pi3, regardless of if enable_uart=1 was set or not set in /boot/config.txt, and therefore regardless of if /dev/ttyS0 exists or not. This in turn would greatly help in resolving issue four for arm-sdk mentioned above.
Thank you.

-- System Information:

Architecture: aarch64

Kernel: Linux 4.10.0-rc5-v8+ (SMP w/4 CPU cores; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages util-linux depends on:
ii  initscripts     2.88dsf-59.2+devuan2
ii  libblkid1       2.26.2-6+devuan1
ii  libc6           2.19-18+deb8u9
ii  libfdisk1       2.26.2-6+devuan1
ii  libmount1       2.26.2-6+devuan1
ii  libncurses5     5.9+20140913-1+b1
ii  libpam0g        1.1.8-3.1+deb8u2
ii  libselinux1     2.3-2
ii  libslang2       2.3.0-2
ii  libsmartcols1   2.26.2-6+devuan1
ii  libtinfo5       5.9+20140913-1+b1
ii  libuuid1        2.26.2-6+devuan1
ii  lsb-base        4.1+devuan2
ii  sysvinit-utils  2.88dsf-59.2+devuan2
ii  tzdata          2017b-0+deb8u1
ii  zlib1g          1:1.2.8.dfsg-2+b1

util-linux recommends no packages.

Versions of packages util-linux suggests:
ii  dosfstools          3.0.27-1
ii  kbd                 1.15.5-2
pn  util-linux-locales  <none>

-- no debconf information