OpenSBI Platform Support Guideline ================================== OpenSBI platform support allows an implementation to define a set of platform specific hooks (hardware manipulation functions) in the form of a *struct sbi_platform* data structure instance. This instance is required by platform independent *libsbi.a* to execute platform specific operations. Each of the reference platform support provided by OpenSBI define an instance of the *struct sbi_platform* data structure. For each supported platform, *libplatsbi.a* integrates this instance with *libsbi.a* to create a platform specific OpenSBI static library. This library is installed in */platform//lib/libplatsbi.a* OpenSBI also provides implementation examples of bootable runtime firmwares for the supported platforms. These firmwares are linked against *libplatsbi.a*. Firmware binaries are installed in */platform//bin*. These firmwares can be used as executable runtime firmwares on the supported platforms as a replacement for the legacy *riskv-pk* boot loader (BBL). A complete doxygen-style documentation of *struct sbi_platform* and related APIs is available in the file *include/sbi/sbi_platform.h*. Adding a new platform support ----------------------------- Support for a new platform named ** can be added as follows: 1. Create a directory named ** under *platform/* directory 2. Create a platform configuration file named *config.mk* under *platform//* directory. This configuration file will provide compiler flags, select common drivers, and select firmware options 3. Create *platform//objects.mk* file for listing the platform specific object files to be compiled 4. Create *platform//platform.c* file providing a *struct sbi_platform* instance A template platform support code is available under the *platform/template* directory. Copying this directory and its content as a new directory named ** under the *platform/* directory will create all the files mentioned above.