proto fw: add loopback event packet

src/libboard_artiq/src/cxp_proto.rs

@@ -187,6 +187,16 @@ pub enum UpConnPacket {
         length: u8,
         data: [u8; DATA_MAXSIZE],
     },
+    Event {
+        conn_id: u32,
+        packet_tag: u8,
+        length: u16,
+        event_size: u16,
+        namespace: u8,
+        event_id: u16,
+        timestamp: u64,
+        data: [u8; 253],
+    },
 }
 
 impl UpConnPacket {
@@ -251,6 +261,43 @@ impl UpConnPacket {
                 let checksum = get_cxp_crc(&writer.get_ref()[4..writer.position()]);
                 writer.write_u32(checksum)?;
             }
+            UpConnPacket::Event {
+                conn_id,
+                packet_tag,
+                length,
+                event_size,
+                namespace,
+                event_id,
+                timestamp,
+                data,
+            } => {
+                let id_bytes = conn_id.to_be_bytes();
+                let length_bytes = length.to_be_bytes();
+
+                // event packet header
+                writer.write_4x_u8(0x07)?;
+
+                writer.write_4x_u8(id_bytes[0])?;
+                writer.write_4x_u8(id_bytes[1])?;
+                writer.write_4x_u8(id_bytes[2])?;
+                writer.write_4x_u8(id_bytes[3])?;
+
+                writer.write_4x_u8(packet_tag)?;
+
+                writer.write_4x_u8(length_bytes[0])?;
+                writer.write_4x_u8(length_bytes[1])?;
+
+                // event message
+                let ev_size = event_size.to_be_bytes();
+                let p2: u8 = ((namespace & 0b11) << 6) | ((event_id & 0xF00) >> 8) as u8;
+                let p3: u8 = (event_id & 0xFF) as u8;
+                writer.write_all(&[ev_size[0], ev_size[1], p2, p3])?;
+                writer.write_all(&timestamp.to_be_bytes())?;
+                writer.write_all(&data[0..event_size as usize])?;
+
+                let checksum = get_cxp_crc(&writer.get_ref()[4..writer.position()]);
+                writer.write_u32(checksum)?;
+            }
             _ => {}
         }
         Ok(())
@@ -383,7 +430,6 @@ pub fn print_packetu32(pak: &[u32], k: &[u8]) {
 
 pub fn downconn_debug_send(channel: usize, packet: &UpConnPacket) -> Result<(), Error> {
     unsafe {
-        // TODO: put this in mem group
         while (CXP[channel].downconn_command_tx_read)() == 1 {}
         let ptr = CXP_LOOPBACK_MEM[0].base as *mut u32;
         let mut writer = Cursor::new(slice::from_raw_parts_mut(ptr as *mut u8, BUF_LEN));