testbench.md

Testbench

The testbench is written in Python 2.7.

As Python is not installed by default on the test machines, we are using pyinstaller to bundle our testbench with Python, into a single binary, which can be executed on its own.

• If any test takes longer than 5 seconds to run, then the testbench will automatically timeout.

• To increase the timeout, change TEST_TIMEOUT as required in test/mips_testbench.py and run make testbench-build on a machine with pyinstaller to rebundle the testbench.

• Alternatively, if Python is installed on the machine, simply run python test/mips_testbench.py <path-to-mips-simulator> to use the testbench

Adding a new test

To add a new test:

1. Create a file in test/src/ with the code to be compiled/assembled:

   • <test-name>.s for MIPS assembly instructions
   • <test-name>.c for C code (note that using standard libraries such as stdio may not work)
     • Implementing input and output should be done by reading and writing to 0x30000000 and 0x30000004 respectively
     • An example of how to do this is shown in test/src/function.04.c

2. Create a file <test-name>.mips.out in test/output/ with:

   • 1st line with the exit code (e.g. 0)
   • Output (checked against stdout) on the rest of the lines

3. Any data to be input into stdin while running the test should be put into a file test/input/<test-name>.in

   • If no input is needed, then there's no need to create the file