Hi Heinrich

From: Heinrich Schuchardt heinrich.schuchardt@canonical.com Sent: Tuesday, November 08, 2022 11:14 PM To: Bin Meng bmeng.cn@gmail.com Cc: Rick Jian-Zhi Chen(陳建志) rick@andestech.com; Leo Yu-Chi Liang(梁育齊) ycliang@andestech.com; Conor Dooley conor.dooley@microchip.com; u-boot@lists.denx.de Subject: Re: [PATCH 1/1] riscv: clarify meaning of CONFIG_SBI_V02

On 11/8/22 16:05, Bin Meng wrote:

...

Hi Heinrich,

On Tue, Nov 8, 2022 at 10:53 PM Heinrich Schuchardt heinrich.schuchardt@canonical.com wrote:

...

Describe that CONFIG_SBI_V02=y does not mean SBI specification v0.2 but v0.2 or later.

Signed-off-by: Heinrich Schuchardt

heinrich.schuchardt@canonical.com

arch/riscv/Kconfig | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4d64e9be3f..ebc4bef220 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -257,16 +257,16 @@ config SBI_V01 deprecated in future once legacy M-mode software are no longer in use.

config SBI_V02

•   bool "SBI v0.2 support"
  

•   bool "SBI v0.2 or later 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.
  

•     The SBI specification introduced the concept of extensions in version
  

•     v0.2. With this configuration option U-Boot can detect and use SBI
  

•     extensions. With the HSM extension introduced in SBI 0.2, only a
  

•     single hart needs to boot and enter the 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
  

•     Choose this option if OpenSBI release v0.7 or above is used
  

• together with U-Boot.

  endchoice

I remember this option was borrowed from the Linux kernel. Do you plan to send patch to Linux kernel too?

Linux uses a single configuration symbol CONFIG_RISCV_SBI_V01 "SBI v0.1 support"

So there is no need for a change there.

SBI v0.1 is really obsolete. Can we drop support for it in U-Boot?

I am fine to remove it.

Thanks, Rick