Questions tagged [serial-console]
The serial-console tag has no usage guidance.
184
questions
0
votes
1
answer
64
views
Serial console: How can I switch off automatic login?
I've got a cluster of four nodes running Debian Bullseye. All of them are connected to a controller board via a UART for admin purposes. The control board uses picocom to access the serial console of ...
- 356
1
vote
1
answer
71
views
How can I set the character to Latn-1 or MCS when using serial-getty?
I'd like to use my old VT420 terminal as system console. Adding RS232 ports and setting up serial-getty are not a problem, but: For years, almost all Linux distros have been using UTF-8 as the ...
- 356
0
votes
1
answer
53
views
What is the equivalent of "clear line con 0"?
What is the equivalent of clear line con 0 in Cisco IOS?
I'm using serial-getty@ttyS0.
- 67
0
votes
1
answer
32
views
KVM: Recover console of VM which connected to console of another VM
How do I recover the console of the first guest when itself is connected to a guest of which it is the host?
Host1:~$ virsh console Guest1
...
Connected to domain 'Guest1'
Escape character is ^] (...
- 67
7
votes
3
answers
1k
views
Is the difference between physical terminal and Linux virtual terminal the use of serial cable?
In the early days of computing, the setup is usually like this:
and we call the VT-100 "physical terminal".
But in Linux, we call virtual terminals "virtual" (the ones accessed by ...
- 327
0
votes
1
answer
71
views
Polkit and local serial consoles
Are serial consoles considered local by polkit? Could that be configured e.g. via /etc/securetty?
- 140
0
votes
1
answer
214
views
Using telnet command without protocol negotiation
I'm using telnet to connect to a serial port via a TCP/IP server. I need a raw, unfiltered, unbuffered connection, and can get most of the way there, but no matter what I do telnet sends protocol ...
- 201
0
votes
1
answer
58
views
Service file and Minicom
I have made a service script which runs a script file after reboot and starts after the service [email protected]. The problem is my script file requires some user inputs to be given but the ...
0
votes
1
answer
65
views
Bricked ssh port
Soo I was playing with firewalld on my ubuntu server instance (Oracle Cloud) and I forgot to add rule for ssh Port so I can't connect to it
I tried using serial console becouse OCI lets you connect to ...
0
votes
0
answers
179
views
using socat or stream to read from serial?
I am trying to send a binary file from Raspbian to an ESP32 device on a RPI USB port, and read response data.
I can cat file > /dev/ttyS0, but obviously ">" discards output from the ...
0
votes
1
answer
484
views
Virtual COM port using only USB cable
I have seen that it is possible to connect two computers by USB cable and make a virtual ethernet bridge or something like that.
My question is, can we do something similar but configure the ...
- 988
0
votes
3
answers
360
views
How to patch kernel to reduce VTIME gap for uart termios API?
I need help to find a kernel patch to get a VTIME from tty termios API lower than 100ms, in order to decrease gap inter char. It blocks read syscall until VTIME timeout.
Function n_tty_read() is the ...
- 27
2
votes
1
answer
787
views
Debian VM doesn’t boot on QEMU with "console=hvc0" kernel parameter
I’m running virtual linux machine (debian12) on QEMU with -device virtconsole argument. That argument adds /dev/hvcX device nodes to VM. QEMU can connect that device to unix socket on host. If i pass “...
- 23
3
votes
1
answer
1k
views
How use a USB (rather than a RS-232) port as a text terminal connection? I hope I am asking this correctly?
I have a Linux system that has USB ports, no RS-232 port. I would like to be able to plug in a USB cable into the Linux system and the other end of the USB cable into my PC, which happens to be ...
1
vote
0
answers
88
views
Redirect pstore to a file
PSTORE description says
pstore is an oops/panic logger that writes its logs to a block device and non-block device
I configured my kernel (embedded system) to store console output to pstore too.
Now ...
- 111
2
votes
1
answer
485
views
System with serial console, which system is responsible for flow control settings
I have a proprietary Linux system, with a proprietary init system, which uses a serial console. I lately noticed, that the xon/xoff flow control is active on this serial console, which poses the risk ...
- 121
3
votes
4
answers
184
views
Protect against vanishing output redirection targets
I have a daemon running on an embedded Linux device with its output redirected to the serial console:
my_daemon > /dev/ttyS0
But now if a user exits the shell running on the serial interface then ...
- 5,983
0
votes
1
answer
256
views
Issues starting headless installation of NetBSD in VirtualBox
On a headless Ubuntu 22.04 machine, I'd like to start a headless installation of NetBSD 9.2 in VirtualBox.
I have a prepared virtual machine with a set of blank disk images attached, as well as with ...
- 342k
0
votes
1
answer
207
views
Dumb terminal agetty keyboard layout filter
I recently acquired an old Heathkit dumb terminal, and I would like to get it working with the colemak keyboard layout. Because the terminal sends ascii codes directly over serial, I don't believe ...
- 31
1
vote
1
answer
420
views
Defining console port in ARM kernel image
I have an ARM Dev board using an RK3566 CPU that I'm building a kernel for.
I would like to control the board using the UART connector. This works during U-Boot process, but my issue is that when I ...
- 23
4
votes
1
answer
907
views
Is there a difference in serial data formatting between Linux and Windows?
I am trying to read in serial data from an RS-485 RFID reader using a RS-485 to USB converter found here and a python script running Pyserial.
The issue I'm facing is that when I print out what is ...
2
votes
2
answers
2k
views
No login prompt from Getty over serial console
My Ubuntu 20.04 system has a serial port over which I would like to provide console access.
I can confirm that I can communicate over the serial port with
sudo picocom -b 115200 /dev/ttyS5
I start ...
- 253
0
votes
0
answers
62
views
What is unit number in /boot/device.hints FreeBSD configuration
In device.hints FreeBSD manpage we have following description:
A device hint line looks like:
hint.driver.unit.keyword="value"
where driver is the name of a device driver, unit is the ...
- 101
3
votes
1
answer
2k
views
Serial device (/dev/serial/) not showing up on Android
Trying to connect a serial device (3d printer) through the USB port in order to communicate with it (klipper firmware) on an Android device (LOS 18.1/Android 11, 3.18 kernel). But I can't find it in /...
- 31
0
votes
0
answers
71
views
screen extensions to vt52
The documentation for the vt52 terminal does not include the codes transmitted for
CTRL+ something, ALT+ something (clearly: they did not exist).
screen launched in vt52 mode sends some keys. For ...
0
votes
2
answers
2k
views
Is it possible to use turn a linux device as a serial device over direct usb?
I have been reading about the Serial Console. So let us say I have an android phone and want to read its serial output from a computer. I can compile a kernel for the phone no problem.
I see things ...
- 53
3
votes
1
answer
570
views
How to get a serial console on a modern Laptop
I would like to observe my Linux system while getting suspended. Reading out the dmesg does not work, because my system stops logging until the device resumes. But that's exactly the problem, my ...
- 338
1
vote
1
answer
1k
views
Missing console output after grub
I'm trying to boot CentOs already installed on an appliance.
This appliance has only two input connectors:
1 USB port, where I plugged in a USB hub, to which I connected a keyboard
1 Male 9 Pin ...
- 111
0
votes
0
answers
1k
views
How to setup serial console on CentOS8/RedHat8?
I rely on serial console on CentOS 8 to debug.
I ever set it up on CentOS 7 by editing file /etc/default/grub as below,
GRUB_CMDLINE_LINUX="crashkernel=auto console=tty0 console=ttyS0,...
- 323
0
votes
1
answer
211
views
How to connect to display (VGA/Console) of one PC from another as a console?
I have an old PC I am trying to configure thru console. Problem is it does not has console or IPMI port.
Instead of hooking a keyboard and monitor to the old PC, I want to connect (somehow) to the &...
- 245
2
votes
1
answer
2k
views
Serial flow control issue with ttyUSB0
This is related to a previous thread I created about a month ago and which was answered.
Today I am attempting to setup a serial console login prompt on a laptop running Ubunutu 20 with a Belkin ...
0
votes
0
answers
172
views
I cannot read from serial port until I login
I have a python script that reads from serial:
import serial
s = serial.Serial("/dev/ttymxc0", 115200)
for i in range(100):
with open("test", 'w') as f:
f.write(s....
- 149
0
votes
1
answer
312
views
Serial connection possibility between Windows and CentOs7
I want to establish connection via putty (serial connection) using UC232a adapter connected to null modem cable, connected to mini-serial-to-DB9 adapter and then to another PC with CentOS 7.
First of ...
2
votes
0
answers
323
views
How to get duplicate boot output on tty and serial console with systemd
In el6 with console=tty0 console=ttyS0,115200 in the kernel cmdline I would get sysvinit and kernel printk output in both the AWS system log and the instance screenshot.
Example showing both printk ...
- 181
3
votes
1
answer
2k
views
Some characters get lost when pasting large amounts of text into serial console
When pasting large amounts of text into a serial console like screen or minicom, some characters get lost and are not being transmitted.
- 3,172
0
votes
2
answers
1k
views
How to set "character tx delay" in GNU screen? (Like in minicom)
Minicom has this useful setting called "character tx delay":
Is there a setting like this for GNU screen, too?
- 3,172
1
vote
1
answer
476
views
find where USB 3.0 device attached
I would like to read a serial input (as for example here) in linux command line but I am not able to find out the attached device (Arduino) path.
I can identify the device:
# lsusb
Bus 005 Device 001: ...
- 113
1
vote
1
answer
261
views
syslinux output duplicated in QEMU serial console
Any idea why syslinux output is duplicated in QEMU serial console?
SeaBIOS (version rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org)
iPXE (http://ipxe.org) 00:03.0 CA00 PCI2.10 PnP PMM+3FF8F290+3FEEF290 ...
- 541
0
votes
2
answers
320
views
Stabilizing serial device names across reboots for serial console
I have an embedded Linux system with 2 built-in serial ports, and a PCI board that adds 8 more.
The kernel enumerates the devices in a way that the port numbers end up getting interleaved, for ...
- 253
1
vote
0
answers
603
views
Minicom - How do I store the newline delay setting?
In Minicom, I prefer to change my Newline tx delay (ms) setting via CTRL-A T to incorporate some delay between newlines, usually 100ms. That way there is a delay when I am pasting something into a ...
- 15
1
vote
0
answers
185
views
Does kernel boot support serial redirection at very high speeds?
I have a UART that is displayed in a Linux boot log as:
AMDI0020:01: ttyS5 at MMIO 0xfedca000 (irq = 4, base_baud = 3000000) is a 16550A
I want to enable Linux kernel boot log to this UART port. To ...
- 216
2
votes
1
answer
1k
views
Is it possible to set serial speed for an early kernel boot log to a MMIO UART?
I have a UART that is displayed in a Linux boot log as:
AMDI0020:01: ttyS5 at MMIO 0xfedca000 (irq = 4, base_baud = 3000000) is a 16550A
I want to enable Linux kernel boot log to this UART port. To ...
- 216
2
votes
0
answers
375
views
How to redirect GRUB2 output to a MMIO serial UART?
Is it possible to redirect GRUB2 output to a MMIO serial UART?
For example I have a UART that is displayed in a Linux boot log as:
AMDI0020:01: ttyS5 at MMIO 0xfedca000 (irq = 4, base_baud = 3000000) ...
- 216
1
vote
1
answer
421
views
How to know the end of an ANSI control code?
I'm working on code for a serial terminal and I'm implementing the ANSI escape codes for moving around the cursor, clearing the screen, etc, and I am curious how to know which to use since there doesn'...
- 53
1
vote
1
answer
1k
views
How do I host a shell for a serial terminal?
I am building a dumb terminal with an arduino and I can now see the output of serial connections. How do I get a login/shell?
I have tried screen /dev/ttyACM0 and that lets me type on the host ...
- 53
0
votes
1
answer
671
views
Serial device ttyS0 is missing after configuring BIOS for console redirect
I am running Alpine Linux on a device on which I was making use of a serial console configured on /dev/ttyS0 to login.
I recently enabled console redirection in my BIOS so that I could use the same ...
- 253
0
votes
0
answers
141
views
Having a shell with console connection without using the physical port in Linux system
A program starts when you are connected to Linux by console port. Otherwise, it refuses to start.
I have to connect to my server remotely by SSH connection. I'm looking for a way to do something to ...
- 137
1
vote
0
answers
125
views
Key mapping on a physical terminal (Teleray 1060) when using getty
I have an old physical terminal (Teleray 1060) that I am attempting to use as a Linux terminal using getty. I have started a login session just fine. However, my terminal lacks an enter key, having ...
- 11
0
votes
1
answer
599
views
reset command over serial connection setting clocal to -clocal
I have a connection from my debian computer to a device with debian linux on it.
If I type the reset command on the serial commandline the clocal will be set to -clocal.
I search the internet why, but ...
- 63
1
vote
1
answer
1k
views
How can I encrypt serial console?
I've my headless linux box configured with a serial console. /etc/default/grub:
GRUB_CMDLINE_LINUX="console=tty0 console=ttyS0,115200"
GRUB_TERMINAL="console serial"
...
- 207