docs: Update docs as per new static library.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>

docs/contributing.md

@@ -24,7 +24,8 @@ Every submitted patch must have this tag.
 followed by a description of the patch content. A blank line and the author
 Signed-off-by tag must follow this description.
 4. A commit subject line must start with a prefix followed by a ":". Common
-prefixes are for example "lib:", "platform:", "firmware:", "docs:" and "top:".
+prefixes are for example "lib:", "platform:", "firmware:", "docs:", "utils:"
+and "top:".
 5. Maintainers should use "Rebase and Merge" when using GitHub to merge pull
 requests to avoid creating unnecessary merge commits.
 6. Maintainers should avoid creating branches directly in the main

docs/library_usage.md

@@ -8,7 +8,11 @@ OpenSBI provides two types of static libraries:
    hooks for the execution of this interface must be provided by the firmware or
    bootloader linking with this library. This library is installed as
    *<install_directory>/lib/libsbi.a*
-2. *libplatsbi.a* - An example platform-specific static library integrating
+2. *libsbiutils.a* - A static library that will contain all common code required
+   by any platform supported in OpenSBI. It will be built by default and included
+   in libplatsbi.a. This library is installed as
+   *<install_directory>/lib/libsbiutils.a*.
+3. *libplatsbi.a* - An example platform-specific static library integrating
    *libsbi.a* with platform-specific hooks. This library is available only for
    the platforms supported by OpenSBI. This library is installed as
    *<install_directory>/platform/<platform_subdir>/lib/libplatsbi.a*

docs/platform_guide.md

@@ -30,7 +30,7 @@ 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, select common drivers, and select firmware options.
+   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*