firmware: add fmt::Display to RoutingTable

artiq/firmware/libboard_artiq/drtio_routing.rs

@@ -1,4 +1,5 @@
 use board_misoc::{csr, config};
+use core::fmt;
 
 pub const DEST_COUNT: usize = 256;
 pub const MAX_HOPS: usize = 32;
@@ -26,6 +27,26 @@ impl RoutingTable {
     }
 }
 
+impl fmt::Display for RoutingTable {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "RoutingTable {{")?;
+        for i in 0..DEST_COUNT {
+            if self.0[i][0] != INVALID_HOP {
+                write!(f, "{}:", i)?;
+                for j in 0..MAX_HOPS {
+                    if self.0[i][j] == INVALID_HOP {
+                        break;
+                    }
+                    write!(f, " {}", self.0[i][j])?;
+                }
+                write!(f, ";")?;
+            }
+        }
+        write!(f, " }}")?;
+        Ok(())
+    }
+}
+
 pub fn config_routing_table(default_n_links: usize) -> RoutingTable {
     let mut ret = RoutingTable::default_master(default_n_links);
     let ok = config::read("routing_table", |result| {