don't read CSR in csrrw(i) with rd=0 #1628
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fix write permission
aswaterman
requested changes
Mar 19, 2024
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According to
The RISC-V Instruction Set Manual Volume I: Unprivileged ISA Document Version 20191213 Table 9.1,
there are some conditional with rd = 0 that inhibit read on CSRs.
Though original implementation is correct in most cases, this always-read implementation may cause some effects. For example, some CSRs that read-write to it may change the architectural state.