1 RISC-V Open Source Supervisor Binary Interface (OpenSBI)
2 ========================================================
4 The **RISC-V Supervisor Binary Interface (SBI)** is a recommended
7 1. A platform specific firmware (M-mode) and a general purpose
8 OS or hypervisor or bootloader (S-mode or HS-mode).
9 2. A hypervisor (HS-mode) and a general purpose OS or bootloader (VS-mode)
11 The *RISC-V SBI specification* is maintained as an independent project
12 by the RISC-V Foundation in [Github](https://github.com/riscv/riscv-sbi-doc)
14 OpenSBI aims to provides an open-source and extensible implementation of
15 the RISC-V SBI specification for case 1 mentioned above. OpenSBI
16 implementation can be easily extended by RISC-V platform or System-on-Chip
17 vendors to fit a particular hardware configuration.
19 OpenSBI provides three components:
21 1. *libsbi.a* - A generic OpenSBI static library
22 2. *libplatsbi.a* - Platform specific OpenSBI static library, that is,
23 libsbi.a plus platform specific hooks
24 3. *firmwares* - Platform specific bootable firmware binaries
26 Building and Installing generic *libsbi.a*
27 ------------------------------------------
29 For cross-compiling, the environment variable *CROSS_COMPILE* must
30 be defined to specify the toolchain executable name prefix, e.g.
31 *riscv64-unknown-elf-* if the gcc executable used is
32 *riscv64-unknown-elf-gcc*.
34 To build the generic OpenSBI library *libsbi.a*, simply execute:
39 All compiled binaries will be placed in the *build* directory.
40 To specify an alternate build directory target, run:
42 make O=<build_directory>
45 To generate files to be installed for using *libsbi.a* in other projects,
50 This will create the *install* directory with all necessary include files
51 and binary files under it. To specify an alternate installation directory,
54 make I=<install_directory> install
57 Building and Installing platform specific *libsbi.a* and firmwares
58 ------------------------------------------------------------------
60 The libplatsbi.a and firmware files are only built if the
61 *`PLATFORM=<platform_subdir>`* argument is specified on make command lines.
62 *`<platform_subdir>`* must specify the path to one of the leaf directories
63 under the *`platform`* directory. For example, to compile the library and
64 firmware for QEMU RISC-V *virt* machine, *`<platform_subdir>`*
65 should be *`qemu/virt`*.
67 To build *libsbi, libplatsbi, and firmwares* for a specific platform, run:
69 make PLATFORM=<platform_subdir>
71 make PLATFORM=<platform_subdir> O=<build_directory>
74 To install *libsbi, headers, libplatsbi, and firmwares*, run:
76 make PLATFORM=<platform_subdir> install
78 make PLATFORM=<platform_subdir> I=<install_directory> install
81 In addition, platform specific make command-line options to top-level make
82 , such as *PLATFORM_<xyz>* or *FW_<abc>* can also be specified. These
83 options are described under *`docs/platform/<platform_name>.md`* and
84 *`docs/firmware/<firmware_name>.md`*.
88 The software is provided under a BSD-2-Clause license. Contributions to this
89 project are accepted under the same license with developer sign-off as
90 described in the [Contributing Guidelines](docs/contributing.md).
92 This project also contains code from other projects as listed below. The original
93 license text is included in those source files.
95 1. The libfdt source code is disjunctively dual licensed (GPL-2.0+ OR BSD-2-Clause). It is
96 used by this project under the terms of the BSD-2-Clause license. Any contributions to
97 this code must be made under the terms of both licenses.
102 A more detailed documentation is under the *docs* directory and organized
105 * *`docs/contributing.md`* - Guidelines for contributing to OpenSBI project
106 * *`docs/platform_guide.md`* - Guidelines for adding new platform support
107 * *`docs/library_usage.md`* - Guidelines for using the static library
108 * *`docs/platform/<platform_name>.md`* - Documentation for the platform *<platform_name>*
109 * *`docs/firmware/<firmware_name>.md`* - Documentation for the firmware *<firmware_name>*
111 The source code is also well documented. For source level documentation,
112 doxygen style is used. Please refer to [Doxygen manual] for details on this
115 [Doxygen manual]: http://www.stack.nl/~dimitri/doxygen/manual.html
117 The Doxygen can be installed on your debian build system using following:
119 sudo apt-get install doxygen doxygen-latex doxygen-doc doxygen-gui graphviz
122 To build a consolidated `refman.pdf` of all documentation, run:
126 make O=<build_directory> docs
129 **NOTE:** `refman.pdf` will be available under `<build_directory>/docs/latex`.
131 To install a consolidated `refman.pdf` of all documentation, run:
135 make I=<install_directory> install_docs
138 **NOTE:** `refman.pdf` will be installed under `<install_directory>/docs`.