use riscv,isa-extensions dt prop for riscv cpus. Signed-off-by: Fin Maaß <f.maass@vogl-electronic.com>
use RISCV_ISA_EXT_A to select ATOMIC_OPERATIONS_BUILTIN or ATOMIC_OPERATIONS_C. Signed-off-by: Fin Maaß <f.maass@vogl-electronic.com>
Currently, the only available platform is Nitrogen, featuring a VexRiscv CPU that boots from external SPI flash and runs code from external HyperRAM. Signed-off-by: Daniel Schultz <dnltz@aesc-silicon.de>