On Tue 01-Nov-2016 7:37 AM, Vasily A. Sartakov wrote: as you might see, this is little bit modified version of trivial.c tests. Usual, when I am testing all tests, there is no problem with this test. But when I am running this file alone, I have a problem. Also, you might see, that there are several free lines with numbers from 16 to 22. I made this not accidental, it is a source of error. If the test_allocator(env_t env) is lockated in the 23rd line, this tests has no problem. But if I add one more free line, I have an error like this: If adding whitespace gives you a different compilation result then that is one bizarre compiler you have. I would check and make sure that this is really what is going on, because it seems fairly improbable to me. Maybe do some multiple runs/builds, 'make clean' between each build etc. Also, I see, that there is a correlation between size of the image and faults: 1349892 ./sel4test-tests.bin_23 1349900 ./sel4test-tests.bin_24 The border line is 1349900 if I have a size of the image below the value -- there is no problem. Unfortunately, 1349900 is not a 'round' value, somehow related to TLB sizes of something else what I know. If virtual address layout changes seem to coincide with faults then I would be checking things like * Context switching code / address space management * TLB/cache/ASID maintenance * Branch predictor / any other hardware state that tracks virtual addresses Note that I'm saying this as someone who knows basically nothing about MIPS, hence the broad suggestions. Adrian