Signed-off-by: Daniel Schaefer <daniel.schaefer@...>
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+= RISC-V SBI specification
+
+SBI (Supervisor Binary Interface) is an interface between the
Supervisor
+Execution Environment (SEE) and the supervisor. It allows the
supervisor to
+execute some privileged operations by using the ecall instruction.
Examples of
+SEE and supervisor are: M-Mode and S-Mode on Unix-class platforms,
where SBI is
+the only interface between them, as well as the Hypervisor extended-
Supervisor
+(HS) and Virtualized Supervisor (VS).
+
+Discussion of SBI occurs on the
+https://lists.riscv.org/g/tech-unixplatformspec[RISC-V Unix Platform
Mailing
+list]. It is publicly readable but posting requires being a member
of the
+RISC-V Foundation. Any new SBI extension needs to be discussed and
approved
+there before being merged.
+
+https://github.com/riscv/opensbi[OpenSBI] is the reference
implementation,
+but other implementations exist; see section "SBI Implementation
IDs".