feat: support DBTR extension (#84)

Ref: https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-debug-triggers.adoc

Signed-off-by: Longbing Zheng <1211998648@qq.com>

sbi-spec/CHANGELOG.md

@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 - fwft: add support for FWFT extension in chapter 18
 - sse: add support for Supervisor Software Events Extension in chapter 17
 - binary: add `HartIds` structure for an iterator over `HartMask`
+- Support `DBTR` extension in Chapter 19
 
 ### Modified
 

sbi-spec/src/dbtr.rs

@@ -0,0 +1,41 @@
+//! Chapter 19. Debug Triggers Extension (EID #0x44425452 "DBTR")
+
+/// Extension ID for Debug Triggers Extension.
+pub const EID_DBTR: usize = crate::eid_from_str("DBTR") as _;
+pub use fid::*;
+
+/// Declared in §19.9.
+mod fid {
+    /// Function ID to get the number of debug triggers on the calling hart.
+    ///
+    /// Declared in §19.1.
+    pub const NUM_TRIGGERS: usize = 0;
+    /// Function ID to set and enable the shared memory for debug trigger configuration on the calling hart.
+    ///
+    /// Declared in §19.2.
+    pub const SET_SHMEM: usize = 1;
+    /// Function ID to read the debug trigger state and configuration into shared memory.
+    ///
+    /// Declared in §19.3.
+    pub const READ_TRIGGERS: usize = 2;
+    /// Function ID to install debug triggers based on an array of trigger configurations.
+    ///
+    /// Declared in §19.4.
+    pub const INSTALL_TRIGGERS: usize = 3;
+    /// Function ID to update already installed debug triggers based on a trigger configuration array.
+    ///
+    /// Declared in 19.5.
+    pub const UPDATE_TRIGGERS: usize = 4;
+    /// Function ID to uninstall a set of debug triggers.
+    ///
+    /// Declared in 19.6.
+    pub const UNINSTALL_TRIGGERS: usize = 5;
+    /// Function ID to enable a set of debug triggers.
+    ///
+    /// Declared in 19.7.
+    pub const ENABLE_TRIGGERS: usize = 6;
+    /// Function ID to disable a set of debug triggers.
+    ///
+    /// Declared in 19.8.
+    pub const DISABLE_TRIGGERS: usize = 7;
+}

sbi-spec/src/lib.rs

@@ -50,6 +50,9 @@ pub mod sta;
 pub mod sse;
 // §18
 pub mod fwft;
+// §19
+pub mod dbtr;
+
 /// Converts SBI EID from str.
 const fn eid_from_str(name: &str) -> i32 {
     match *name.as_bytes() {
@@ -362,4 +365,18 @@ mod tests {
         const_assert_eq!(0, SET);
         const_assert_eq!(1, GET);
     }
+    // §19
+    #[test]
+    fn test_dbtr() {
+        use crate::dbtr::*;
+        const_assert_eq!(0x44425452, EID_DBTR);
+        const_assert_eq!(0, NUM_TRIGGERS);
+        const_assert_eq!(1, SET_SHMEM);
+        const_assert_eq!(2, READ_TRIGGERS);
+        const_assert_eq!(3, INSTALL_TRIGGERS);
+        const_assert_eq!(4, UPDATE_TRIGGERS);
+        const_assert_eq!(5, UNINSTALL_TRIGGERS);
+        const_assert_eq!(6, ENABLE_TRIGGERS);
+        const_assert_eq!(7, DISABLE_TRIGGERS);
+    }
 }