riscv: Add Kconfig option for SBI v0.2

SBI v0.2 is more scalable and extendable to handle future needs
for RISC-V supervisor interfaces. For example, with SBI v0.2 HSM
extension, only a single hart need to boot and enter operating
system. The booting hart can bring up secondary harts one by one
afterwards.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a252cdbb7138d8c2aa3c1418ce390ccec260570b..c72987181364333d0ae49dc14e58222835d88132 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -226,14 +226,32 @@ config SBI
        bool
        default y if RISCV_SMODE || SPL_RISCV_SMODE
 
+choice
+       prompt "SBI support"
+       default SBI_V01
+
 config SBI_V01
        bool "SBI v0.1 support"
-       default y
        depends on SBI
        help
          This config allows kernel to use SBI v0.1 APIs. This will be
          deprecated in future once legacy M-mode software are no longer in use.
 
+config SBI_V02
+       bool "SBI v0.2 support"
+       depends on SBI
+       help
+         This config allows kernel to use SBI v0.2 APIs. SBI v0.2 is more
+         scalable and extendable to handle future needs for RISC-V supervisor
+         interfaces. For example, with SBI v0.2 HSM extension, only a single
+         hart need to boot and enter operating system. The booting hart can
+         bring up secondary harts one by one afterwards.
+
+         Choose this option if OpenSBI v0.7 or above release is used together
+         with U-Boot.
+
+endchoice
+
 config SBI_IPI
        bool
        depends on SBI