mirror of
https://git.rtems.org/rtems-docs/
synced 2025-05-16 23:52:41 +08:00
67 lines
2.9 KiB
ReStructuredText
67 lines
2.9 KiB
ReStructuredText
.. comment SPDX-License-Identifier: CC-BY-SA-4.0
|
|
|
|
.. comment: Copyright (c) 2018 Chris Johns <chrisj@rtems.org>
|
|
.. comment: All rights reserved.
|
|
|
|
.. _tester-consoles:
|
|
|
|
Consoles
|
|
--------
|
|
|
|
The RTEMS Tester uses the target's console output to determine the state of a
|
|
test. Console interfaces vary depending on the testing mode, the BSP, and the
|
|
target hardware.
|
|
|
|
Consoles for simulator work best if mapped to the simulator's ``stdout``
|
|
interface. The RTEMS Tester can capture and process the ``stdout`` data from a
|
|
simulator while it is running.
|
|
|
|
Target hardware console interfaces can vary. The most universal and stable
|
|
interface target hardware is a UART interface. There are a number of physical
|
|
interfaces for UART data these days. They are:
|
|
|
|
#. RS232
|
|
|
|
#. TTL
|
|
|
|
#. USB
|
|
|
|
RS232 is still present on a number of targets. The best solution is to use a
|
|
RS232 to USB pod and convert the port to USB.
|
|
|
|
TTL is common on a number of boards where cost is important. A console
|
|
interface is typically a development tool and removing the extra devices need
|
|
to convert the signal to RS232 or directly to USB is not needed on production
|
|
builds of the target. There is a standard header pin out for TTL UART consoles
|
|
and you can purchase low cost cables with the header and a built in UART to USB
|
|
converter. The cables come is different voltage levels so make sure you check
|
|
and use the correct voltage level.
|
|
|
|
The USB interface on a target is typcially a slave or OTG interface and all you
|
|
need to a standard USB cable.
|
|
|
|
We recommend a low cost and low power device to be a terminal server. A
|
|
Raspberry Pi or similar low cost computer running Linux can be set up quickly
|
|
and with a powered USB hub and can support a number of USB UART ports. A USB
|
|
hub with a high power port is recommended that can suppy the Raspberry Pi.
|
|
|
|
The open source daemon ``ser2net`` is easy to configure to map the USB UART
|
|
ports to the Telnet protocol. There is no need for security because a typical
|
|
test environment is part of a lab network that should be partitioned off from
|
|
an enginnering or corportate network and not directly connected to the
|
|
internet.
|
|
|
|
A test set up like this lets you place a terminal server close to your target
|
|
hardware providing you with the flexibility to select where you run the RTEMS
|
|
Tester. It could be your desktop or an expensive fast host machine in a server
|
|
rack. None of this equipment needs to directly interface to the target
|
|
hardware.
|
|
|
|
The RTEMS Tester directly supports the telnet protcol as a console and can
|
|
interface to the ``ser1net`` server. The telnet console will poll the server
|
|
waiting for the remote port to connect. If the terminal server ``ser2net`` does
|
|
not have a ``tty`` device it will not listen on the port assigned to that
|
|
``tty``. A USB ``tty`` can come and go depending on the power state of the
|
|
hardware and the target hardware's design and this can cause timing issues if
|
|
the target hardware is power cycled as part of a reset process.
|