proto fw: add print u32 packet helper function

src/libboard_artiq/src/cxp_proto.rs

@@ -192,13 +192,30 @@ pub fn print_packet(pak: &[u8]) {
     println!("============================================");
 }
 
+pub fn print_packetu32(pak: &[u32]) {
+    println!("pak = [");
+    for i in 0..(pak.len()) {
+        let data: [u8; 4] = pak[i].to_be_bytes();
+        println!(
+            "{:#03}     {:#04X} {:#04X} {:#04X} {:#04X},",
+            i + 1,
+            data[0],
+            data[1],
+            data[2],
+            data[3]
+        )
+    }
+    println!("]");
+    println!("============================================");
+}
+
 pub fn downconn_debug_main() {
     downconn_debug_send(&Packet::CtrlRead {
         addr: 0x00,
         length: 0x04,
     });
 
-    const LEN: usize = 100;
+    const LEN: usize = 40;
     let mut pak_arr: [u32; LEN] = [0; LEN];
     let mut i: usize = 0;
     unsafe {
@@ -213,9 +230,7 @@ pub fn downconn_debug_main() {
         }
     }
 
-    // TODO: turn the u32 slice back to u8
-
-    println!("{:#010X?}", pak_arr)
+    print_packetu32(&pak_arr)
 }
 
 pub fn downconn_debug_send(packet: &Packet) -> Result<(), Error> {