exceptions in p and v environments
timsifive opened this issue · comments
I'm writing tests for misaligned accesses, which requires the exception to be handled in the test if the hardware doesn't support misaligned accesses. This works great in the p test environment (copying the pattern from breakpoint.S), but not at all in the v environment. These environments look completely different. In p, it calls mtvec_handler (if it's defined) from trap_vector, in p/riscv_test.h. In v, it jumps to wtf from trap_vector, defined in v/entry.S.
Why do these two environments handle this so differently, to the point where they even put the functionality in different files? Can I make the v environment more like the p environment to deal with this?
The v environment essentially requires tests be exception-free.
OK. Should I do the misaligned tests outside of lw.S etc? Is there something I can check for in the test that lets me skip the tests if they have to be exception-free?
I could #define EXCEPTION_FREE 1 in v/riscv_test.h
Please don't. Tests meant to execute in the v VM are exception-free. Tests that might cause exceptions just shouldn't run in that VM. The test should be moved to a directory like rv32mi etc.; those VMs permit exceptions.
OK. I'll put the misaligned tests in a separate file. Thanks.