RFC: Adding support for ARM (RNDR etc.) to RngDxe

Rebecca Cran <rebecca@...>

Currently, RngDxe in SecurityPkg only supports Intel, with RdRand support.

This RFC is to start a discussion about adding support for ARM.

I have a Git branch with support for the optional ARMv8.5 RNDR instruction at https://github.com/bcran/edk2/commits/bcran-rndr which moves the existing Intel support into a Rand directory, and adds code to support RNDR in a new AArch64 directory.

There are other RNG implementations available for ARM, including platform-specific approaches on Graviton (https://lwn.net/Articles/790304/) and other platforms, so a more thorough rearchitecting/redesign may be desired.

Rebecca Cran