riscv: add Kconfig entries for the C and A ISA extensions

Add Kconfig entries for the C (compressed instructions) and A (atomic
instructions) ISA extensions. Only the C ISA extension is selectable.
This matches the configuration in Linux.

The Kconfig entries are not used yet. A follow-up patch will select the
appropriate compiler flags based on the Kconfig configuration.

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Lukas Auer 2018-11-22 11:26:14 +01:00 committed by Andes
parent 711585649e
commit d57ffa650f

View File

@ -38,6 +38,17 @@ config ARCH_RV64I
endchoice
config RISCV_ISA_C
bool "Emit compressed instructions"
default y
help
Adds "C" to the ISA subsets that the toolchain is allowed to emit
when building U-Boot, which results in compressed instructions in the
U-Boot binary.
config RISCV_ISA_A
def_bool y
config 32BIT
bool