New KConfig options for 'A' and 'M' RISC-V extensions have been
added. These are used to configure the '-march' string used by GCC
to produce a compatible binary for the requested RISC-V variant.
In order to maintain compatibility with all currently defined SoC,
default the options for HW mul / Atomics support to 'y', but allow
them to be overridden for any SoC which does not support these.
I tested this change locally via twister agaisnt a few RISC-V platforms
including some 32bit and 64bit. To verify the 4 possibilities of Atomics
& HW Mul: (No, No), (No, Yes), (Yes, No), (Yes, Yes -- current behavior),
I used an out-of-tree GCC (xPack RISC-V GCC) which has multilib support
for rv32i, rv32ia, rv32ima to test against our out-of-tree Intel Nios V/m
processor in HW. The Zephyr SDK RISCV GCC currently does not contain
multilib support for all variants exposed by these new KConfig options.
Signed-off-by: Nathan Krueger <nathan.krueger@intel.com>
6a5520c626