force-amo: allowing AMOxxx instructions for riscv32imc #57
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almindor
approved these changes
Oct 31, 2023
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This PR solves #56 |
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The E310X atomic support is limited, as it only allows us to use AMO instructions, while LR/SC instructions provoke an exception. Thus, we need to provide support for
riscv32imc-unknown-none-elfto use LR/SC instructions viaportable-atomic. However, currently you either use emulation of all the atomic instructions or a faulty atomic target.This PR uses a new version of
portable-atomic, which added a new feature to use real AMO instructions forriscv32imc-unknown-none-elftargets while emulating LR/SC instructions. This is particularly well-suited for the E310x microcontroller. Note that the MSRV is now 1.72.As a side note: In my opinion, this microcontroller does not deserve to be called a
riscv32imactarget. We should stop supportingriscv32imacand clearly document this particularity, asking users to always useriscv32imcwithportable-atomicandforce-amowhen needed.