The user interface¶
The GUI of EduMIPS64 is inspired to WinMIPS64 user interface. In fact, the main window is identical, except for some menus.
The EduMIPS64 main window is composed by a menu bar and six frames, showing different aspects of the simulation. There’s also a status bar, that has the double purpose to show the content of memory cells and registers when you click them and to notify the user that the simulator is running when the simulation has been started but verbose mode is not selected. There are more details in the following section.
The GUI is composed by seven frames, six of which are visible by default, and one (the I/O frame) is hidden.
The Cycles frame shows the evolution of the execution flow during time, showing for each time slot which instructions are in the pipeline, and in which stage of the pipeline they are located.
The Registers frame shows the content of each register. By left-clicking on them you can see in the status bar their decimal (signed) value, while double-clicking on them will pop up a dialog that allows the user to change the value of the register.
The Statistics frame shows some statistics about the program execution.
The Pipeline frame shows the actual status of the pipeline, showing which instruction is in which pipeline stage. Different colors highlight different pipeline stages.
The Memory frame shows memory cells content, along with labels and comments taken from the source code. Memory cells content, like registers, can be modified double-clicking on them, and clicking on them will show their decimal value in the status bar. The first column shows the hexadecimal address of the memory cell, and the second column shows the value of the cell. Other columns show additional info from the source code.
The Code window shows the instructions loaded in memory. The first column shows the address of the instruction, while the second column shows the hexadecimal representation of the instructions. Other columns show additional info taken from the source code.
The Input/Output window provides an interface for the user to see the output that the program creates through the SYSCALLs 4 and 5. Actually it is not used for input, as there’s a dialog that pops up when a SYSCALL 3 tries to read from standard input, but future versions will include an input text box.
Dialogs are used by EduMIPS64 to interact with the user in many ways. Here’s a summary of the most important dialogs:
In the Settings dialog various aspects of the simulator can be configured. Clicking on the “OK” button will cause the options to be saved, while clicking on “Cancel” (or simply closing the window) will cause the changes to be ignored. Don’t forget to click “OK” if you want to save your changes.
The Main Settings tab allow to configure forwarding and the number of steps in the Multi Cycle mode.
The Behavior tab allow to enable or disable warnings during the parsing phase, the “Sync graphics with CPU in multi-step execution” option, when checked, will synchronize the frames’ graphical status with the internal status of the simulator. This means that the simulation will be slower, but you’ll have an explicit graphical feedback of what is happening during the simulation. If this option is checked, the “Interval between cycles” option will influence how many milliseconds the simulator will wait before starting a new cycle. Those options are effective only when the simulation is run using the “Run” or the “Multi Cycle” options from the Execute menu.
The last two options set the behavior of the simulator when a synchronous exception is raised. If the “Mask synchronous exceptions” option is checked, the simulator will ignore any Division by zero or Integer overflow exception. If the “Terminate on synchronous exception” option is checked, the simulation will be halted if a synchronous exception is raised. Please note that if synchronous exceptions are masked, nothing will happen, even if the termination option is checked. If exceptions are not masked and the termination option is not checked, a dialog will pop out, but the simulation will go on as soon as the dialog is closed. If exceptions are not masked and the termination option is checked, the dialog will pop out, and the simulation will be stopped as soon as the dialog is closed.
The last tab allows to change the colors that are associated to the different pipeline stages through the frames. It’s pretty useless, but it’s cute.
The Dinero Frontend dialog allows to feed a DineroIV process with the trace file internally generated by the execution of the program. In the first text box there is the path of the DineroIV executable, and in the second one there must be the parameters of DineroIV.
The lower section contains the output of the DineroIV process, from which you can take the data that you need.
The Help dialog contains three tabs with some indications on how to use the simulator. The first one is a brief introduction to EduMIPS64, the second one contains informations about the GUI and the third contains a summary of the supported instructions.
Command line options¶
Three command line options are available. They are described in the following list, with the long name enclosed in round brackets. Long and short names can be used in the same way.
- -v (–version) prints the simulator version and exits.
- -h (–help) prints a help message with a brief summary of command line options, then exits.
- -f (–file) filename opens filename in the simulator
- -r (–reset) resets the stored configuration to the default values
- -d (–debug) enters Debug mode
The –debug flag has the effect to activate Debug mode. In this mode, a new frame is available, the Debug frame, and it shows the log of internal activities of EduMIPS64. It is not useful for the end user, it is meant to be used by EduMIPS64 developers.
The EduMIPS64 .jar file can act both as a stand-alone executable .jar file and as an applet, so it can be executed in both ways. Both methods need the Java Runtime Environment, version 5 or later.
To run it as a stand-alone application, the java executable must be issued in this way: java -jar edumips64-version.jar, where the version string must be replaced with the actual version of the simulator. On some systems, you may be able to execute it by just clicking on the .jar file.
To embed it in an HTML, the <applet> tag must be used. The EduMIPS64 web site contains a page that already contains the applet, so that everyone can execute it without the hassle of using the command line.