RISC-V Open Source Supervisor Binary Interface (OpenSBI) ======================================================== The **RISC-V Supervisor Binary Interface (SBI)** is a recommended interface between: 1. Platform specific firmware running in M-mode and general-purpose-os/hypervisor/bootloader running in S-mode/HS-mode 2. Hypervisor runnng in HS-mode and general-purpose-os/bootloader running in VS-mode The **RISC-V SBI specification** is maintained as independent project by RISC-V Foundation on [Github](https://github.com/riscv/riscv-sbi-doc) The **RISC-V OpenSBI project** aims to provides an open-source and extensible implementation of the **RISC-V SBI specification** for point 1) mentioned above. It can be easily extended by RISC-V platform or RISC-V System-on-Chip vendors. We can create three things using the RISC-V OpenSBI project: 1. **libsbi.a** - Generic OpenSBI static library 2. **libplatsbi.a** - Platform specific OpenSBI static library (It is libsbi.a plus platform specific hooks represented by "platform" symbol) 3. **firmwares** - Platform specific firmware binaries How to Build? ------------- For cross-compiling, please ensure that CROSS_COMPILE environment variable is set before starting build system. The libplatsbi.a and firmwares are optional and only built when `PLATFORM=` parameter is specified to top-level make. (**NOTE**: `` is sub-directory under platform/ directory) To build and install Generic OpenSBI library do the following: 1. Build **libsbi.a**: `make` OR `make O=` 2. Install **libsbi.a and headers**: `make install` OR `make I= install` To build and install platform specific OpenSBI library and firmwares do the following: 1. Build **libsbi, libplatsbi, and firmwares**: `make PLATFORM=` OR `make PLATFORM= O=` 2. Install **libsbi, headers, libplatsbi, and firmwares**: `make PLATFORM= install` OR `make PLATFORM= I= install` In addition, we can also specify platform specific command-line options to top-level make (such as `PLAT_` or `FW_`) which are described under `docs/platform/.md` OR `docs/firmware/.md`. Documentation ------------- All our documenation is under `docs` directory organized in following manner: * `docs/platform_guide.md` - Guidelines for adding new platform support * `docs/library_usage.md` - Guidelines for using static library * `docs/platform/.md` - Documentation for `` platform * `docs/firmware/.md` - Documentation for firmware `` We also prefer source level documentation, so wherever possible we describe stuff directly in the source code. This helps us maintain source and its documentation at the same place. For source level documentation we strictly follow Doxygen style. Please refer [Doxygen manual] (http://www.stack.nl/~dimitri/doxygen/manual.html) for details.