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
Wesley Norris (repnop)