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diff --git a/docs/chamelium.txt b/docs/chamelium.txt new file mode 100644 index 00000000..77594284 --- /dev/null +++ b/docs/chamelium.txt @@ -0,0 +1,153 @@ +Chamelium Support in IGT +======================== + +This document provides information, instructions and a tasks list for Chamelium +support in IGT. + +Introduction +------------ + +The Chamelium is a platform that acts as a display monitor emulator. It provides +advanced access and control over the various signals a display receives. + +As such, it allows testing display features that can otherwise not be tested in +IGT without external hardware. + +The platform was developed by Google in order to test display and audio-related +features of ChromeOS devices. It was initially developed internally by Google as +part of the ChromeOS effort under the name Chameleon and was later made external +as part of the ChromiumOS effort, under the name Chamelium. + +It consists of a custom-made display emulator board connected to an Arrow SoCKit +via a flexible cable, with two DisplayPort connectors, one HDMI and one VGA. + +The SoCKit uses a Cyclone V SoC, with both a FPGA and an ARM CPU. While the FPGA +is used for logic control, the CPU runs daemons that allow the board to be +controlled over the network via a XMLRPC interface. + +Documentation +------------- + +Documentation about the Chamelium is made available by Google through the +ChromiumOS projet wiki: https://www.chromium.org/chromium-os/testing/chamelium + +Deploying the Chamelium With IGT +-------------------------------- + +Instructions from the ChromiumOS wiki detail how to setup the Chamelium: +https://www.chromium.org/chromium-os/testing/chamelium#TOC-Setting-up-Chamelium + +The should be followed up until the "Setup your Linux host, DUT and the FPGA" +section. At this point, IGT has to be configured to connect to the Chamelium. + +It may be necessary to give the Chamelium a static IP address, depending on +the network setup. This can be configured (via the serial console) by editing +the Debian-styled /etc/network/interfaces configuration file. + +Chamelium support requires setting up dedicated IGT configuration, as explained +in the Core and Chamelium parts of the IGT API Reference in the documentation. + +Note that running the chamelium tests with the Chamelium configuration deployed +and the Chamelium disconnected or unreachable will result in network timeouts +that take seconds. It is thus preferable (especially in the case of an automated +CI system with a shared testlist) to remove the Chamelium configuration from the +hosts that shouldn't connect to the Chamelium so that they can be skipped, which +is faster than a network timeout. + +An example fully-featured configuration follows: +[Common] +FrameDumpPath=/root/ + +[Chamelium] +URL=http://192.168.72.1:9992 + +[Chamelium:DP-1] +ChameliumPortID=1 + +[Chamelium:HDMI-A-2] +ChameliumPortID=3 + +[Chamelium:VGA-1] +ChameliumPortID=4 + +[DUT] +SuspendResumeDelay=2 + +Debugging the Chamelium +----------------------- + +Logs that may be useful for debugging can be obtained either by connecting to +the board via SSH or serial console and looking at the daemon logs from +/var/log, such as: +$ tail -f /var/log/chameleon* + +Daemon Source, Build and Deploy +------------------------------- + +Source code for the daemon running on the Chamelium is available at: +https://chromium.googlesource.com/chromiumos/platform/chameleon/ + +Building the daemon requires a GNU EABI ARMv7 GCC toolchain, that must be +specified via the CC variable, such as: +$ make CC=arm-linux-gnueabihf-gcc + +The result can be deployed to the chamelium with the remote-install target and +specifying the network address for the chamelium via the CHAMELEON_HOST +variable, such as: +$ make remote-install CHAMELEON_HOST=192.168.72.1 + +The process requires the Chamelium to be connected to the Internet to succeed. + +Contributing Changes to the Daemon +---------------------------------- + +Contributions to the Chamelium daemon, just like any contribution to ChromiumOS, +are submitted and reviewed at: https://chromium-review.googlesource.com/ + +The ChromiumOS project provides an extensive developer guide: +https://www.chromium.org/chromium-os/developer-guide that assumes running within +the ChromiumOS build system. Since this is likely not the case for contributing +to the Chamelium daemon, only the part about uploading changes is relevant: +https://www.chromium.org/chromium-os/developer-guide#TOC-Upload-your-changes-and-get-a-code-review + +Most of the process is about using the Gerrit web interface for submitting and +having the change reviewed and not forgetting the Change-Id, TEST= and BUG= +fields in the commit. + +Current Support in IGT +---------------------- + +Support for the Chamelium platform in IGT is found in the following places: +* lib/igt_chamelium.c: library with Chamelium-related helpers +* tests/chamelium.c: sub-tests using the Chamelium + +As of late August 2017, the following features are tested by IGT: +* Pixel-by-pixel frame integrity tests for DP and HDMI +* Error-trend-based frame integrity tests for VGA +* CRC-based frame integrity tests for DP and HDMI +* Hotplug event simple tests for all interfaces +* Hotplug event stressing tests, emulating a flaky cable for DisplayPort and + HDMI +* Hotplug event during suspend test for all interfaces, either separately for + each interface or combined +* EDID display identifier integrity check for all interfaces +* EDID display identifier change during suspend for all interfaces + +Future Developments +------------------- + +With the current generation of the hardware platform, support for testing a +number of additional display features could be included as future developments, +including: +* Audio capture from HDMI and DP +* High-bandwidth Digital Content Protection (HDCP) streaming to the display +* Remote control forwarding (CEC) sent from the display +* YUV colorspace for HDMI, instead of RGB +* Partial testing of DP Multi-Stream Transport (MST) using an external MST hub + and the two available DP connectors of the platform + +While HDCP is already supported by the Chamelium daemon, features such as CEC +and YUV are not and must be implemented there before any support for them can +be added to IGT. Audio is supported by the Chamelium daemon for HDMI only and +a way to retrieve the captured data via the XMLRPC interface needs to be added +to the daemon. |