[Qemu-devel] [Bug 1188991] [NEW] Unable to do serial communication using -chardev tty

[Franco]

Public bug reported:


Im running an Linux Image (kernel 3.2.8) for beagleboard-xm on QEMU's
1.4.0 emulator.


What I want to do is to have a communication between guest and host across 
serial the 4 differents ttyO present on the guest. QEMU offer facilities to 
redirect the trafic to some device in the host side.

The command that I use to lauch QEMU is :

    sudo qemu-system-arm -M beaglexm -m 1024 -sd ./test.img -clock unix
-see -device usb-kbd -chardev tty,id=mytty,path=/dev/ttyS0

As it says in the QEMU's manual -chardev is suppose to connect to a
local tty device at the path given

My problem goes like this:

At the guest kernel boot I'm able to see that my UART where enabled

    [    2.682040] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
    [    2.777947] omap_uart.0: ttyO0 at MMIO 0x4806a000 (irq = 72) is a OMAP 
UART0
    [    2.794967] omap_uart.1: ttyO1 at MMIO 0x4806c000 (irq = 73) is a OMAP 
UART1
    [    2.814942] omap_uart.2: ttyO2 at MMIO 0x49020000 (irq = 74) is a OMAP 
UART2
    [    2.966825] console [ttyO2] enabled
    [    2.984777] omap_uart.3: ttyO3 at MMIO 0x49042000 (irq = 80) is a OMAP 
UART3

In fact, when I go see in to /proc/tty/driver and I do a cat on OMAP-
SERIAL Im able to see this serinfo:1.0 driver revision:

    0: uart:OMAP UART0 mmio:0x4806A000 irq:72 tx:0 rx:0 CTS|DSR|CD
    1: uart:OMAP UART1 mmio:0x4806C000 irq:73 tx:0 rx:0 CTS|DSR|CD
    2: uart:OMAP UART2 mmio:0x49020000 irq:74 tx:268 rx:37 RTS|CTS|DTR|DSR|CD
    3: uart:OMAP UART3 mmio:0x49042000 irq:80 tx:0 rx:0 CTS|DSR|CD

I know that ttyO2 is working because my console is been redirected to
it. The thing is that doing a set serial on any of the ttyO I get the
following message:

     address@hidden driver]# setserial -a /dev/ttyO0
    /dev/ttyO0, Line 0, UART: undefined, Port: 0x0000, IRQ: 72
        Baud_base: 3000000, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal

The same goes with ttyO2. I tryed to set some sethings to any of the
ttyO with setserial but I always get the same message:

    address@hidden ~]# setserial /dev/ttyO0 uart 8250                           
   
    setserial: can't set serial info: Invalid argument
    address@hidden ~]# setserial /dev/ttyO0 port 0x4806a000
    setserial: can't set serial info: Invalid argument

basicly I want to establish a serial communication between a guest and a
host, but the serial ports on the guest side aren't well configured.

When I open ttyS0 with minicom on the host side and do on the guest side

    echo "test" > /dev/ttyO0

The host recives nothing.

Anyone can tell me how I could remove tty modules on the guest side and
try to insert it again to see if the setup resets properly or give me
any advice on how to solve this problem. Plus if anyone has already
tryed doing this kind on serial communication I would like to here from
you.

Thank,
Francisco

** Affects: qemu
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1188991

Title:
  Unable to do serial communication using -chardev tty

Status in QEMU:
  New

Bug description:

  Im running an Linux Image (kernel 3.2.8) for beagleboard-xm on QEMU's
  1.4.0 emulator.

  
  What I want to do is to have a communication between guest and host across 
serial the 4 differents ttyO present on the guest. QEMU offer facilities to 
redirect the trafic to some device in the host side.

  The command that I use to lauch QEMU is :

      sudo qemu-system-arm -M beaglexm -m 1024 -sd ./test.img -clock
  unix -see -device usb-kbd -chardev tty,id=mytty,path=/dev/ttyS0

  As it says in the QEMU's manual -chardev is suppose to connect to a
  local tty device at the path given

  My problem goes like this:

  At the guest kernel boot I'm able to see that my UART where enabled

      [    2.682040] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
      [    2.777947] omap_uart.0: ttyO0 at MMIO 0x4806a000 (irq = 72) is a OMAP 
UART0
      [    2.794967] omap_uart.1: ttyO1 at MMIO 0x4806c000 (irq = 73) is a OMAP 
UART1
      [    2.814942] omap_uart.2: ttyO2 at MMIO 0x49020000 (irq = 74) is a OMAP 
UART2
      [    2.966825] console [ttyO2] enabled
      [    2.984777] omap_uart.3: ttyO3 at MMIO 0x49042000 (irq = 80) is a OMAP 
UART3

  In fact, when I go see in to /proc/tty/driver and I do a cat on OMAP-
  SERIAL Im able to see this serinfo:1.0 driver revision:

      0: uart:OMAP UART0 mmio:0x4806A000 irq:72 tx:0 rx:0 CTS|DSR|CD
      1: uart:OMAP UART1 mmio:0x4806C000 irq:73 tx:0 rx:0 CTS|DSR|CD
      2: uart:OMAP UART2 mmio:0x49020000 irq:74 tx:268 rx:37 RTS|CTS|DTR|DSR|CD
      3: uart:OMAP UART3 mmio:0x49042000 irq:80 tx:0 rx:0 CTS|DSR|CD

  I know that ttyO2 is working because my console is been redirected to
  it. The thing is that doing a set serial on any of the ttyO I get the
  following message:

       address@hidden driver]# setserial -a /dev/ttyO0
      /dev/ttyO0, Line 0, UART: undefined, Port: 0x0000, IRQ: 72
          Baud_base: 3000000, close_delay: 50, divisor: 0
          closing_wait: 3000
          Flags: spd_normal

  The same goes with ttyO2. I tryed to set some sethings to any of the
  ttyO with setserial but I always get the same message:

      address@hidden ~]# setserial /dev/ttyO0 uart 8250                         
     
      setserial: can't set serial info: Invalid argument
      address@hidden ~]# setserial /dev/ttyO0 port 0x4806a000
      setserial: can't set serial info: Invalid argument

  basicly I want to establish a serial communication between a guest and
  a host, but the serial ports on the guest side aren't well configured.

  When I open ttyS0 with minicom on the host side and do on the guest
  side

      echo "test" > /dev/ttyO0

  The host recives nothing.

  Anyone can tell me how I could remove tty modules on the guest side
  and try to insert it again to see if the setup resets properly or give
  me any advice on how to solve this problem. Plus if anyone has already
  tryed doing this kind on serial communication I would like to here
  from you.

  Thank,
  Francisco

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1188991/+subscriptions