MAU_TRY_WITHOUT_MMU: should this handle EXCEPT_RISCV_INST_MISALIGNED?

intel / MultiArchUefiPkg

Multi-Architecture UEFI Environment Driver

GNU Lesser General Public License v2.1

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MAU_TRY_WITHOUT_MMU: should this handle EXCEPT_RISCV_INST_MISALIGNED? #34

Open andreiw opened 11 months ago

andreiw commented 11 months ago

I've never seen this in the wild, but I suppose it is possible.

andreiw commented 11 months ago

According to the ISA doc, "Instruction-address-misaligned exceptions are not possible on machines that support extensions with 16-bit aligned instructions, such as the compressed instruction-set extension, C.". See page 21 of 20191213.

andreiw commented 11 months ago

In short, it's easy to add EXCEPT_RISCV_INST_MISALIGNED handling, but impossible to test it, short of hacking together a custom qemu/sbi/edk2 build to target rv64g instead of rv64gc. Will skip this, esp. given the corner case (not running with an MMU, which is an unsupported scenario anyway).