This crate provides a safe, pure-Rust implementation of the RISC-V Supervisor Binary Interface (SBI) to be used in S-mode software, such as operating system kernels. This crate implements the v2.0-rc5 version of the SBI specification and aims to stay up to date with it as newer versions of the specification are released.

Important safety note

Since this crate is meant to be used by S-mode software, it is assumed that you are executing the provided functions from within S-mode with a spec compliant SBI implementation running in M-mode (or S-mode in the case of VS-mode), and considers execution from any other operating mode out of the scope of this crate, which may bring with it memory safety concerns in those environments. Consider this an implicit contract when using the crate.

SBI extension support

Extension implementation state legend:

✅ - Fully implemented

🚧 - Partially implemented

❌ - Not implemented

Standard SBI extensions

SBI extensions implementation state

Legacy ✅

Function	Extension ID	Implemented
Set timer	0	✅
Console putchar	1	✅
Console getchar	2	✅
Clear IPI	3	✅
Send IPI	4	✅
Remote FENCE.I	5	✅
Remote SFENCE.VMA	6	✅
Remote SFENCE.VMA with ASID	7	✅
Shutdown	8	✅

Base ✅

Function	Function ID	Implemented
Get SBI specification version	0	✅
Get SBI implementation ID	1	✅
Get SBI implementation version	2	✅
Probe SBI extension	3	✅
Get machine vendor ID	4	✅
Get machine architecture ID	5	✅
Get machine implementation ID	6	✅

Timer ✅

Function	Function ID	Implemented
Set timer	0	✅

Interprocessor Interrupt (IPI) ✅

Function	Function ID	Implemented
Send IPI	0	✅

RFENCE ✅

Function	Function ID	Implemented
Remote FENCE.I	0	✅
Remote SFENCE.VMA	1	✅
Remote SFENCE.VMA with ASID	2	✅
Remote HFENCE.GVMA with VMID	3	✅
Remote HFENCE.GVMA	4	✅
Remote HFENCE.VVMA with ASID	5	✅
Remote HFENCE.VVMA	6	✅

Hart State Management ✅

Function	Function ID	Implemented
Hart start	0	✅
Hart stop	1	✅
Get hart status	2	✅
Hart suspend	3	✅

System Reset ✅

Function	Function ID	Implemented
System reset	0	✅

Performance Monitoring Unit ✅

Function	Function ID	Implemented
Get number of counters	0	✅
Get counter information	1	✅
Configure matching counters	2	✅
Start counters	3	✅
Stop counters	4	✅
Read firmware counter	5	✅

Debug Console ✅

Function	Function ID	Implemented
Console write	0	✅
Console read	1	✅
Console write byte	2	✅

System Suspend ✅

Function	Function ID	Implemented
System suspend	0	✅

Collaborative Processor Performance Control ✅

Function	Function ID	Implemented
Probe CPPC register	0	✅
Read CPPC register	1	✅
Read CPPC register high bits	2	✅
Write CPPC register	3	✅

Nested Acceleration Extension ❌

Function	Function ID	Implemented
Probe nested acceleration feature	0	❌
Set nested acceleration shared memory	1	❌
Synchronize shared memory CSRs	2	❌
Synchronize shared memory HFENCEs	3	❌
Synchronize shared memory and emulate SRET	4	❌

Steal-Time Accounting ❌

Function	Function ID	Implemented
Set steal-time shared memory address	0	❌

Experimental, vendor-specific, and firmware-specific extensions

Experimental, vendor-specific, and firmware-specific SBI extensions are provided as opt-in crate features.

The currently supported non-standard SBI extensions are:

Experimental

There are currently no supported experimental SBI extensions.

Vendor-specific

There are currently no supported vendor-specific SBI extensions.

Firmware-specific

There are currently no supported firmware-specific SBI extensions.

License

sbi is licensed under the Mozilla Public License 2.0