[RFC PATCH v2 7/7] docs: opensbi_config: add description for reserved-pmp-count

[Yu-Chien Peter Lin]

Add documentation for the reserved-pmp-count property, which
specifies the number of additional high-priority PMP entries.

Signed-off-by: Yu-Chien Peter Lin <peter.lin at sifive.com>
---
 docs/opensbi_config.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/docs/opensbi_config.md b/docs/opensbi_config.md
index 104d82c9..085f4c73 100644
--- a/docs/opensbi_config.md
+++ b/docs/opensbi_config.md
@@ -26,6 +26,14 @@ The DT properties of a domain configuration DT node are as follows:
 * **heap-size** (Optional) - When present, the specified value is used
   as the size of the heap in bytes.
 
+* **reserved-pmp-count** (Optional) - When present, the specified value
+  is used as the additional number of reserved high-priority PMP entries.
+  These entries may be allocated dynamically at runtime, or permanently
+  reserved to protect, for example, PMA unsafe regions.
+  When smePMP is enabled, a minimum of one reserved entry is required
+  for sbi_hart_map_addr/sbi_hart_unmap_saddr; therefore, the final
+  reserved entry count will be (1 + reserved-pmp-count).
+
 * **system-suspend-test** (Optional) - When present, enable a system
   suspend test implementation which simply waits five seconds and issues a WFI.
 
@@ -40,6 +48,7 @@ The OpenSBI Configuration Node will be deleted at the end of cold boot
             compatible = "opensbi,config";
             cold-boot-harts = <&cpu1 &cpu2 &cpu3 &cpu4>;
             heap-size = <0x400000>;
+            reserved-pmp-count = <2>;
             system-suspend-test;
         };
     };
-- 
2.39.3