Javacard applet to measure memory usage. Uses JCSystem.getAvailableMemory.
Install ant and the Javacard SDKs.
Build using JC_HOME=SDKPATH/jc304_kit ant dist
Deploy to the card using gp --install javacard-memory.cap [ --params AABBCCDD ], with the optional installation parameter being a 32 bit unsigned big-endian integer specifying the base free persistent space. This value will be stored and reported back later. By default, if no parameter is specified, this value is 00028F38, which means 167736 bytes for the flexSecure. For the Apex Flex, use 00014970, which means 84336 bytes.
Install Python3 and pyscard, and run ./measure.py. Measure once before installing your applet to test, and once afterwards.
The applet return measurement data as a response to the select command. See the measure script for details.