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Diffstat (limited to 'roms/opensbi/docs/platform_guide.md')
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diff --git a/roms/opensbi/docs/platform_guide.md b/roms/opensbi/docs/platform_guide.md new file mode 100644 index 000000000..7920fac2a --- /dev/null +++ b/roms/opensbi/docs/platform_guide.md @@ -0,0 +1,42 @@ +OpenSBI Platform Support Guideline +================================== + +The 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 +the platform-independent *libsbi.a* to execute platform-specific operations. + +Each of the reference platform supports provided by OpenSBI defines 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 *<install_directory>/platform/<platform_subdir>/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 +*<install_directory>/platform/<platform_subdir>/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 support for a new platform +--------------------------------- + +Support for a new platform named *<xyz>* can be added as follows: + +1. Create a directory named *<xyz>* under the *platform/* directory. +2. Create a platform configuration file named *config.mk* under the + *platform/<xyz>/* directory. This configuration file will provide + compiler flags, and select firmware options. +3. Create a *platform/<xyz>/objects.mk* file for listing the + platform-specific object files to be compiled. +4. Create a *platform/<xyz>/platform.c* file providing a *struct sbi_platform* + instance. + +A platform support code template is available under the *platform/template* +directory. Copying this directory and its content as a new directory named +*<xyz>* under the *platform/* directory will create all the files mentioned +above. |