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>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index b81e0d9..0de77a7 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -38,6 +38,17 @@
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