[PATCH 1/5] risv: add missing SBI extension definitions

Sean Anderson seanga2 at gmail.com
Sat Mar 6 22:48:39 CET 2021

On 3/6/21 12:59 AM, Bin Meng wrote:
> On Fri, Mar 5, 2021 at 1:02 AM Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>> Add the System Reset Extension and the Hart State Management Extension
>> definitions.
>> Add missing RFENCE Extension enum values.
>> The SBI 0.1 extension constants are needed for for the sbi command. Remove
>> an #ifdef.
>> Cf. https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc
>> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
>> ---
>>   arch/riscv/include/asm/sbi.h | 36 ++++++++++++++++++++++++++++++++++--
>>   1 file changed, 34 insertions(+), 2 deletions(-)
> U-Boot does not need HSM.


As far as I can tell, it's completely conforming for all harts but one
to be put into the STOPPED state by the SBI (with the expectation that
U-Boot or something else start them). Also, while we currently figure
out which harts to start via device tree passed from SBI, that behavior
is not standardized. Going forward, I we may see some SBI
implementations which communicate this sort of info through HSM. Though
this has not happened yet...


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