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Currently, frame buffer handling in gem5 is quite ad hoc. In practice, we pass around naked pointers to raw pixel data and expect consumers to convert frame buffers using the (broken) VideoConverter. This changeset completely redesigns the way we handle frame buffers internally. In summary, it fixes several color conversion bugs, adds support for more color formats (e.g., big endian), and makes the code base easier to follow. In the new world, gem5 always represents pixel data using the Pixel struct when pixels need to be passed between different classes (e.g., a display controller and the VNC server). Producers of entire frames (e.g., display controllers) should use the FrameBuffer class to represent a frame. Frame producers are expected to create one instance of the FrameBuffer class in their constructors and register it with its consumers once. Consumers are expected to check the dimensions of the frame buffer when they consume it. Conversion between the external representation and the internal representation is supported for all common "true color" RGB formats of up to 32-bit color depth. The external pixel representation is expected to be between 1 and 4 bytes in either big endian or little endian. Color channels are assumed to be contiguous ranges of bits within each pixel word. The external pixel value is scaled to an 8-bit internal representation using a floating multiplication to map it to the entire 8-bit range.
This is the gem5 simulator. The main website can be found at http://www.gem5.org A good starting point is http://www.gem5.org/Introduction, and for more information about building the simulator and getting started please see http://www.gem5.org/Documentation and http://www.gem5.org/Tutorials. To build gem5, you will need the following software: g++ or clang, Python (gem5 links in the Python interpreter), SCons, SWIG, zlib, m4, and lastly protobuf if you want trace capture and playback support. Please see http://www.gem5.org/Dependencies for more details concerning the minimum versions of the aforementioned tools. Once you have all dependencies resolved, type 'scons build/<ARCH>/gem5.opt' where ARCH is one of ALPHA, ARM, NULL, MIPS, POWER, SPARC, or X86. This will build an optimized version of the gem5 binary (gem5.opt) for the the specified architecture. See http://www.gem5.org/Build_System for more details and options. With the simulator built, have a look at http://www.gem5.org/Running_gem5 for more information on how to use gem5. The basic source release includes these subdirectories: - configs: example simulation configuration scripts - ext: less-common external packages needed to build gem5 - src: source code of the gem5 simulator - system: source for some optional system software for simulated systems - tests: regression tests - util: useful utility programs and files To run full-system simulations, you will need compiled system firmware (console and PALcode for Alpha), kernel binaries and one or more disk images. Please see the gem5 download page for these items at http://www.gem5.org/Download If you have questions, please send mail to gem5-users@gem5.org Enjoy using gem5 and please share your modifications and extensions.