• Jeffrey Lee's avatar
    Remove CSDB architecture version warnings · c2d2385d
    Jeffrey Lee authored
    Although CSDB was only codified at around the time that ARMv8.4 was
    introduced, there aren't any architecture version restrictions placed on
    it in the ARMv8 ARM, and the encoding was even added to a new edition of
    the ARMv7 ARM, also without any architecture version restrictions.
    For ordinary instructions this would feel a lot like a documentation
    error, but since CSDB is a barrier instruction which fits inside a
    NOP-like address space (MSR which doesn't write to any PSR fields), and
    it was introduced as part of Arm's Spectre/Meltdown mitigations, it's
    likely that Arm did their homework and confirmed that the encoding has
    the correct behaviour on all (licensed) implementations.
    The ARMv7 ARM only goes back to ARMv4, but it's likely that older CPUs
    also implement CSDB correctly, by virtue of the fact that they'll be too
    old to be doing any speculative execution.
    With the above in mind, it should be safe to remove our "ARMv8.4 or
    later" warning from the disassembly.
    Version 2.08. Tagged as 'Debugger-2_08'
VersionASM 848 Bytes