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=ttyS0,115200n8 intel_iommu=on modprobe.blacklist=nouveau,amdgpu"
	GRUB_DISABLE_RECOVERY="true"
	GRUB_TERMINAL="console serial"
	GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"

and execute "grub2-mkconfig -o /boot/grub2/grub.cfg" then reboot. It worked like a charm But this time it doesn't work on CentOS 8. Could anyone shed light on it?

How do you enable hardware flow control for the Linux serial console? Perhaps using GRUB arguments? This post asks about specifying arguments to QEMU and GRUB to use the serial console, but doesn't address hardware flow control.

I've got a machine running OpenSuSE Leap 15.5, which can be remote-controlled both by usign a local serial line (RS232), and via network (SSH). Now I've got an /etc/issue file auto-generated by /usr/sbin/issue-generator upon every system startup. Here is the content of /etc/issue:

Welcome to \S - Kernel \r (\l).

eth0: \4{eth0} \6{eth0}

It's obvious that the eth0 line doesn't make very much sense when accessing the machine via serial line. Here I would rather expect something like this: ttyS5 vt340 115200 8N1 And this is what /etc/sysconfig/issue-generator looks like (comments omitted):

NETWORK_INTERFACE_REGEX="^[be]"

This makes it necessary for the getty process in use (I'm using agetty for the serial line) to find out which interface the terminal is attached to and to adapt the line stated above accordingly, but how? This is the serial getty service file (comments omitted):

[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=rc-local.service

Before=getty.target
IgnoreOnIsolate=yes

Conflicts=rescue.service
Before=rescue.service

[Service]
ExecStart=-/sbin/agetty -L 115200 %I $TERM
Type=idle
Restart=always
UtmpIdentifier=%I
TTYPath=/dev/%I
TTYReset=yes
TTYVHangup=yes
IgnoreSIGPIPE=no
SendSIGHUP=yes

[Install]
WantedBy=getty.target

I would like to log the kernel messages of system to the serial console on ttyS0. A similar problem was addressed under How to get kernel messages on serial console on a systemd system? but I still don't get it to work. I've got systemd.journald.max_level_console=debug console=ttyS0,115200 loglevel=7 on my kernel command line and ShowStatus=no set in */etc/systemd/system.conf* Nevertheless, while I'll see kernel messages on the console at the beginning of the boot process, after the Journal Service is started I wont get any more kernel messages logged to the console. If I, as an example, connect a USB mouse to the board, there is nothing logged to the console but journalctl -f shows: Feb 11 10:09:45 a20 kernel: usb 3-1: new low-speed USB device number 4 using ohci-platform Feb 11 10:09:45 a20 kernel: usb 3-1: New USB device found, idVendor=046d, idProduct=c069, bcdDevice=56.01 Feb 11 10:09:45 a20 kernel: usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 Feb 11 10:09:45 a20 kernel: usb 3-1: Product: USB Laser Mouse Feb 11 10:09:45 a20 kernel: usb 3-1: Manufacturer: Logitech Feb 11 10:09:45 a20 kernel: input: Logitech USB Laser Mouse as /devices/platform/soc/1c14400.usb/usb3/3-1/3-1:1.0/0003:046D:C069.0005/input/input6 Feb 11 10:09:45 a20 kernel: hid-generic 0003:046D:C069.0005: input,hidraw2: USB HID v1.10 Mouse [Logitech USB Laser Mouse] on usb-1c14400.usb-1/input0 Any thoughts?

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 serial console. How can I store this setting? Currently I need to set it every time I open a minicom instance. I would have thought that this setting would be located inside the minicom configuration, but it seems to be more of a runtime setting.

I have a binary file(obtained from assembly code). I need to transfer this file to an fpga serially via ttyUSB0. I read in some posts that using cat and echo data can be transferred to ttyS0.

echo -ne '\033[2J' > /dev/ttyS1  
cat  < /dev/ttyS1

Does this apply for ttyUSB0 as well? If not, please suggest me other ways to transfer binary file via ttyUSB0.

I have a Wandboard IMX 6 with Android OS. I can't read RS232 data. I was wrote an app for this on QtCreator with C++. I have an issue. When i pressed the connect button i take serial port is being used for no permission to open error. I listed my available serial ports a dropdown menu. I can see ttymxc0 and ttymxc2 on dropdown but can't connect.

When using the serial console of my system I always end up with $COLUMNS=80 and $LINES=24. While I can change these variables manually it is somewhat annoying to do this any time when the client side terminal window has been resized. Usually I'm connecting to the console using screen /dev/mytty baudrate. Changing the $TERM environment variable to "screen" or "xterm" does not help. Will I need to call getty with some of those instead of vt100? Needless to say that all of this works fine, when I connect to the same machine using ssh.

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 /dev/serial/, it only shows up as /dev/ttyUSB0 and /dev/bus/usb/001/00[^1] and I can't communicate with it through those. I've compiled the kernel with the ch341.c driver. 'lsusb -v' from a chrooted Debian through Linux deploy gives the following output, the device in question is called 'QinHeng Electronics CH340...':

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               3.00
  bDeviceClass            9 Hub
  bDeviceSubClass         0
  bDeviceProtocol         3
  bMaxPacketSize0         9
  idVendor           0x1d6b Linux Foundation
  idProduct          0x0003 3.0 root hub
  bcdDevice            3.18
  iManufacturer           3 Linux 3.18.140-Swan-gcb3e40e597b0-dirty xhci-hcd
  iProduct                2 xHCI Host Controller
  iSerial                 1 xhci-hcd.0.auto
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x001f
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xe0
      Self Powered
      Remote Wakeup
    MaxPower                0mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         9 Hub
      bInterfaceSubClass      0
      bInterfaceProtocol      0 Full speed (or root) hub
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0004  1x 4 bytes
        bInterval              12
        bMaxBurst               0
Hub Descriptor:
  bLength              12
  bDescriptorType      42
  nNbrPorts             1
  wHubCharacteristic 0x000a
    No power switching (usb 1.0)
    Per-port overcurrent protection
  bPwrOn2PwrGood       10 * 2 milli seconds
  bHubContrCurrent      0 milli Ampere
  bHubDecLat          0.0 micro seconds
  wHubDelay             0 nano seconds
  DeviceRemovable    0x00
 Hub Port Status:
   Port 1: 0000.02a0 5Gbps power Rx.Detect
Binary Object Store Descriptor:
  bLength                 5
  bDescriptorType        15
  wTotalLength       0x000f
  bNumDeviceCaps          1
  SuperSpeed USB Device Capability:
    bLength                10
    bDescriptorType        16
    bDevCapabilityType      3
    bmAttributes         0x02
      Latency Tolerance Messages (LTM) Supported
    wSpeedsSupported   0x0008
      Device can operate at SuperSpeed (5Gbps)
    bFunctionalitySupport   3
      Lowest fully-functional device speed is SuperSpeed (5Gbps)
    bU1DevExitLat           0 micro seconds
    bU2DevExitLat           0 micro seconds
can't get debug descriptor: Resource temporarily unavailable
Device Status:     0x0001
  Self Powered

Bus 001 Device 003: ID 1a86:7523 QinHeng Electronics CH340 serial converter
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass          255 Vendor Specific Class
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0         8
  idVendor           0x1a86 QinHeng Electronics
  idProduct          0x7523 CH340 serial converter
  bcdDevice            2.64
  iManufacturer           0
  iProduct                2 USB Serial
  iSerial                 0
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0027
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0x80
      (Bus Powered)
    MaxPower               98mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           3
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      1
      bInterfaceProtocol      2
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0020  1x 32 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0020  1x 32 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               1
can't get debug descriptor: Resource temporarily unavailable
Device Status:     0x0000
  (Bus Powered)

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            9 Hub
  bDeviceSubClass         0
  bDeviceProtocol         1 Single TT
  bMaxPacketSize0        64
  idVendor           0x1d6b Linux Foundation
  idProduct          0x0002 2.0 root hub
  bcdDevice            3.18
  iManufacturer           3 Linux 3.18.140-Swan-gcb3e40e597b0-dirty xhci-hcd
  iProduct                2 xHCI Host Controller
  iSerial                 1 xhci-hcd.0.auto
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0019
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xe0
      Self Powered
      Remote Wakeup
    MaxPower                0mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         9 Hub
      bInterfaceSubClass      0
      bInterfaceProtocol      0 Full speed (or root) hub
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0004  1x 4 bytes
        bInterval              12
Hub Descriptor:
  bLength               9
  bDescriptorType      41
  nNbrPorts             1
  wHubCharacteristic 0x000a
    No power switching (usb 1.0)
    Per-port overcurrent protection
    TT think time 8 FS bits
  bPwrOn2PwrGood       10 * 2 milli seconds
  bHubContrCurrent      0 milli Ampere
  DeviceRemovable    0x00
  PortPwrCtrlMask    0xff
 Hub Port Status:
   Port 1: 0000.0103 power enable connect
can't get device qualifier: Resource temporarily unavailable
can't get debug descriptor: Resource temporarily unavailable
Device Status:     0x0001
  Self Powered

How can I communicate with the serial device? Are there any other kernel modules I should compile? Does newer Android handle serial devices in a different way than Linux does? I've seen other people run this firmware on Android in chrooted Linux like here , here , here . So it is possible, I just must be missing something. I'm happy to post other debugging information/logs.

I am trying to use a usb cable from a Raspberry (in peripheral mode, serial CDC ACM) to a PC to access GRUB2 serial console (on the PC). I succeeded with a pl2303 usb ttl adapter, the usbserial_pl2303 module in grub works ok. But what I want is instead to use directly a usb cable in what is called "usb gadget". I correctly configured the Raspberry to act like a peripheral, both with the g_serial module and the libcomposite module. After the PC starts it sees the Raspberry as a "CDC Abstract Control Model" and I can use the "serial" connection on /dev/ttyACM0. It works with both g_serial and libcomposite. But only AFTER the PC starts. It does not work in GRUB. I tried to enable all the 3 grub usbserial modules (usbserial_pl2303, usbserial_ftdi, usbserial_usbdebug) but terminfo and terminal_output do not show any new terminal. The grub command "usb" shows the connected usb "device" (i.e. the Raspberry) as a "CDC Abstract Control Model" but clearly it is not able to use it as a serial terminal. Again, if I connect the usb pl2303 adapter to the PC, grub sees it and I can connect to grub serial console. So my question is: how can I convince GRUB2 to see the CDC ACM "serial" port and use it as a terminal?

For better or worse, I hooked up my VT320 to my Linux machine. I'm trying to run some software on, but the serial connection seems to end up in a crashed state whenever somes emojis are rendered. Not sure if it's important, but in this case it was the 🎲 (die) emoji. Instead, I get a mirrored question mark and the terminal doesn't render anything else. I know emojis would never work. I'll settle for an incorrect character or none at all, but I would like to know if it's possible to avoid freezing the connection. In case it's relevant, this is how agetty is configured in /lib/systemd/system/serial-getty@.service. I opted for the VT220, as it's the closest to what I have.

ExecStart=-/sbin/agetty -h -L 19200 %I vt220

Output of stty -a:

speed 19200 baud; rows 24; columns 80; line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = ;
eol2 = ; swtch = ; start = ^Q; stop = ^S; susp = ;
rprnt = ; werase = ; lnext = ; discard = ;
min = 1; time = 0;
-parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff
-iuclc -ixany -imaxbel -iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon -iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
-echoctl echoke -flusho -extproc

I'm trying to use a Minitel as a console to connect to my Ubuntu. I've read a lot of information about this, but it seems to work with older versions of Ubuntu. These two files : - etc/inittab - etc/gettydefs ... don't do the job for me ! My inittab: 1:2345:respawn:/sbin/agetty ttyUSB0 4800v23 My gettydefs : 4800v23# B4800 CS7 PARENB -PARODD GLOBAL # B4800 ISTRIP CS7 PARENB -PARODD GLOBAL BRKINT IGNPAR ICRNL IXON IXANY OPOST ONLCR CREAD HUPCLISIG ICANON ECHO ECHOE ECHOK #@S login: #4800v23 The result of "sudo lsusb -v" : Bus 003 Device 002: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 255 Vendor Specific Class bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 8 idVendor 0x1a86 QinHeng Electronics idProduct 0x7523 HL-340 USB-Serial adapter bcdDevice 2.64 iManufacturer 0 iProduct 2 USB Serial iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 0x0027 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 98mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 3 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 1 bInterfaceProtocol 2 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 1 can't get debug descriptor: Resource temporarily unavailable Device Status: 0x0000 (Bus Powered) Today I can do this : sudo stty -F /dev/ttyUSB0 4800 parenb cs7 hupcl cread ignpar clocal ixon ixoff opost onlcr isig echoe echok echoctl echoke and this : echo "Hello Minitel" > /dev/ttyUSB0 ... prints Hello Minitel on my Minitel screen. But I'm not able to have a prompt on my minitel. Thanks for your help, and sorry for my "poor english" (I'm an old french developer ;)

# Background I'm running FreeBSD 12.1-RELEASE as a host for [bhyve](https://www.freebsd.org/cgi/man.cgi?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. According to the manual page, in order to start the VM with two TTY-class devices I have to start bhyve with command-line options similar to those: -l com1,/dev/nmdm0B -l com2,/dev/nmdm1B. Then I should be able to connect to the guest via those two [nullmodem terminals](https://www.freebsd.org/cgi/man.cgi?nmdm) with cu -l /dev/nmdm0A and cu -l /dev/nmdm1A. # Problem The first command works as expected: cu -l /dev/nmdm0A shows me the main console of the guest. The second command, however, attaches to the guest, but shows nothing. I would expect to show me a login prompt as if switched to another TTY. *What am I missing?* --- ## Additional details - The guest is a fresh installation of FreeBSD. - The output of dmesg | grep uart on the guest is as follows:

uart0:  port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
    uart0: console (115200,n,8,1)
    uart1:  port 0x2f8-0x2ff irq 3 on acpi0

- I've tried setting hint.uart.1.flags first to 0x10 and then to 0x80 (although this one is for kernel debuggers from what I understand from [uart(4)](https://www.freebsd.org/cgi/man.cgi?uart)) and rebooted after each change. It didn't work. ### References - https://bsdjhb.blogspot.com/2018/10/using-bhyve-for-freebsd-development.html - https://gist.github.com/landonf/d00a15ede7d5ccb0e371

How can I install OpenBSD on my HP Server using the serial console, without external monitor? I have no monitor in the Datacenter, but I have my Laptop with Debian/GNU/Linux. So far so good. How do you make under OpenBSD a bootable USB stick? To install OpenBSD over the serial console without the need of an external monitor?

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 the respective node. Now I've got an issue: When typing exit, the respective node logs me back in and starts a new shell immediately. I also get the root shell without having to type in username and password. Apparently, an instance of agetty is providing the shell:

root@blade3n2:~# ps -ef | grep getty
root        1127       1  0 18:27 tty1     00:00:00 /sbin/agetty -o -p -- \u --noclear tty1 linux
root        1836    1646  0 18:35 ttyFIQ0  00:00:00 grep getty

As this is a security flaw to me, I'd like to switch off this behavior, so that… - …I'll have to log in with user name and password each time I connect to one of the nodes, and… - …I'll get disconnected and picocom closed when a session is closed (with an exit or somehow else). **UPDATE:** After receiving some advice, I did some diagnostics:

root@blade3n1:~# ps -fwwwC agetty
UID          PID    PPID  C STIME TTY          TIME CMD
root        1121       1  0 20:55 tty1     00:00:00 /sbin/agetty -o -p -- \u --noclear tty1 linux

root@blade3n1:~# pstree -ap 1121
agetty,1121 -o -p -- \\u --noclear tty1 linux

root@blade3n1:~# grep -r ttyFIQ0 /etc

root@blade3n1:~# systemctl cat serial-getty@ttyFIQ0.service
# /lib/systemd/system/serial-getty@.service
#  SPDX-License-Identifier: LGPL-2.1+
#
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[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 ge>
After=rc-local.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 --autologin root --noclear %I $TER
#ExecStart=-/sbin/agetty -o '-p -- \\u' --keep-baud 115200,38400,9600 %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

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 standard character set, whereas the VT only speaks Latin-1 (ISO 8859-1) and the old DEC multinational character set. So: What can I do to make serial-getty use one of the character sets supported by the terminal? Is there an easy-to-implement solution for that? My current distros are: - OpenSuSE Leap 15.6 - OpenWRT, current version Please note that the VT420 does allow to define custom (bitmap) characters, but this is hard work.

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 the Getty instance with sudo systemctl start serial-getty@ttyS5 which starts the command /sbin/agetty -o '-p -- \u' --keep-baud 115200,38400,9600 ttyS5 vt220 However, no login prompt appears on the remote system.

I'm working on a raspberry pi, and trying to paste some text files into a command-line text editor nano... but the text ends up corrupted on the remote end (partial/incomplete text). I can only guess the paste function of my PC (xubuntu 16.04) is pushing the data too fast (the serial baud is 115200). Can I slow down the paste function somehow?

What is the equivalent of clear line con 0 in Cisco IOS? I'm using serial-getty@ttyS0.

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 ^] (Ctrl + ])

Guest2 login:

Guest1 has been connected to Guest2 using the virsh console Guest2 command. Guest2 runs on Guest1 with the same KVM and LIBVIRT packages as Guest1 does on Host1. I do not want to reboot any machine. I possess the credentials of all machines.