transport: Specify the doorbell register width for P2A doorbell

Signed-off-by: Rahul Pathak <[email protected]>
riscv-non-isa · Dec 30, 2024 · a5af049 · a5af049
1 parent cca9f37
commit a5af049
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/transport.adoc b/src/transport.adoc
@@ -77,6 +77,9 @@ If the P2A doorbell is a MSI then the application processors must configure
 the MSI on the platform microcontroller side using the RPMI service defined by
 the `BASE` service group.
 
+The doorbell register must support write operation or a read-modify-write sequence
+on a 32-bit memory-mapped register.
+
 NOTE: If the platform supports PLIC, the platform need to provide a MMIO
 register to inject an edge-triggered interrupt.