Questions tagged [serial-console]

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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 ...
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How to open a TTY session during startup and begin logging

Struggling to write a script that will open a TTY session during startup or shortly and continuously log. Context: I have an on small PC that is being deployed as an on prem syslog server running ...
0 votes
1 answer
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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 ...
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1 answer
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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 ...
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1 answer
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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 ...
4 votes
1 answer
173 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 ...
0 votes
1 answer
267 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 ...
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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 ...
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printk output not going to serial despite console=ttyS0

I'm running Ubuntu 20 and I have enabled the serial console via the Linux command line: BOOT_IMAGE=/boot/vmlinuz-5.13.0-30-generic root=UUID=6a751af0-b71b-4984-ad67-40696101ef50 ro console=ttyS0,...
1 vote
1 answer
466 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 /...
0 votes
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what are the kernel options for usb console debugging?

I would like to attach an USB to Serial Adapter on my laptop to read out the errors while putting the computer into suspension mode. I am on Pop!_OS, so the closest instructions I could find where in ...
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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
463 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 ...
2 votes
1 answer
131 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 ...
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Multiple hops XON/XOFF

I'm back! With the same issue but slightly different. In two previous threads with the help of some folks here I was able to resolve some issues I was experiencing with flow control and a vintage ...
1 vote
1 answer
301 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 ...
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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,...
0 votes
1 answer
97 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 &...
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2 votes
1 answer
533 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 ...
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0 answers
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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....
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1 answer
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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
151 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 ...
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2 votes
1 answer
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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.
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2 answers
516 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?
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1 vote
1 answer
147 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: ...
0 votes
1 answer
124 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 ...
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0 votes
2 answers
132 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 ...
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1 vote
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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 ...
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1 vote
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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 ...
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2 votes
1 answer
318 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 ...
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1 vote
0 answers
172 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) ...
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1 vote
1 answer
83 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'...
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2 votes
1 answer
335 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 ...
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0 votes
1 answer
240 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 ...
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0 answers
35 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 ...
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2 votes
0 answers
81 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 ...
1 vote
1 answer
160 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 ...
1 vote
1 answer
405 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" ...
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What termios settings cause endpoint to get garbled serial?

I have two endpoints. One is Windows Subsystem for Linux (Ubuntu) and the other is a small AR9331 router (running OpenWRT and has 16550 chip). They are connected over a USB-to-Serial connection. ...
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/dev/ttyS0 doesn't give back prompt after mount

I created a file system and after the mount command i don't get back the prompt in serial port. I connected to the system also via SSH and i see the mount has been finished. the serial port continue ...
0 votes
4 answers
4k views

How to store console output to a file

I am running embedded Linux and my command line has console=/dev/ttyO0,.... I have terminal program connected to this UART and can see EVERYTHING produced by the system. Now, when running in the field,...
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1 vote
1 answer
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Login prompt is not output correctly, thus not able to log into Linux through ttyS0

My system is a intel Atom based board without a vedio card, communication can be carried out through serial port(at baut rate of 115200) and ethernet port. I installed CentOS through PXE, after ...
2 votes
1 answer
344 views

How to Configure OpenSSH Server to connect to an isolated computer's console via a serial port?

Imagine the following scenario: "Client" and "Connected" both exist on a network. A third computer, "Isolated," is not on any network but exposes a console over a serial ...
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1 vote
2 answers
405 views

How can I block a normal user from logging in via the serial console (`ttyS0`) without blocking root?

How can I block a normal user on a Ubuntu/Redhat from logging in via the serial console (ttyS0) without blocking root ? Only root needs console access, no other users. I have cleared /etc/securetty, ...
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3 votes
0 answers
157 views

Is there a way to change where systemd sends its output during shutdown?

I want systemd to send shutdown messages to a TTY that is different from the one that was used during bootup. More specifically, if the system starts to shutdown, the system should send any messages ...
0 votes
0 answers
957 views

Garbled serial console output even with correct baud rate

I'm trying to connect to a headless NAS box via serial console, and have reached a wall that even Google can't seem to help with. I have a USB to 3.5mm serial cable, with the USB end going into my ...
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6 votes
1 answer
519 views

How to active the second console to a FreeBSD guest running in bhyve?

Background I'm running FreeBSD 12.1-RELEASE as a host for bhyve virtual machines. I have a FreeBSD 12.1-RELEASE guest running inside a VM. I would like to have two TTY-class devices configured for it. ...
1 vote
1 answer
2k views

How to enter message in serial communication using screen

I use screen \dev\ttyUSB0 command to connect to virtual serial port. It prints out the incoming communication, but I dont know how to send message back to the connected device. Thanks for answers ...
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Make sslh or nginx listen to serial port, to get VPN or HTTP(S) or SSH over serial port (real, emulated and/or virtual)

I would like to make more services than serial-console-login available via serial-port. In essence, I want to make a traditionally network-listening service (with strong encryption/authentication) of ...
1 vote
0 answers
2k views

Samsung SMT-G7401 hack

Samsung SMT-G7401 hack introduction I have an SMT-G7401_PCS01B (Horizon box) from UPC Switzerland and I would like to install debian or multimedia linux distribution on it if is it possible, if is ...
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