From 9205974b509937abd0f587c80736a2807533fa18 Mon Sep 17 00:00:00 2001
From: Mirna <mshetairy@google.com>
Date: Thu, 15 Oct 2020 19:54:34 +0200
Subject: [PATCH] Update nfct_test example to test NFC driver.

---
 examples/nfct_test.rs | 67 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 56 insertions(+), 11 deletions(-)

diff --git a/examples/nfct_test.rs b/examples/nfct_test.rs
index 1432dfd..42176cd 100644
--- a/examples/nfct_test.rs
+++ b/examples/nfct_test.rs
@@ -1,24 +1,69 @@
+#![no_std]
+
 extern crate alloc;
 extern crate lang_items;
 
 use core::fmt::Write;
 use libtock_drivers::console::Console;
-// use libtock_drivers::nfc;
+use libtock_drivers::nfc::NfcTag;
+
+#[allow(dead_code)]
+/// Helper function to write a slice into a fixed
+/// length transmission buffer.
+fn write_tx_buffer(buf: &mut [u8], slice: &[u8]) {
+    for (i, &byte) in slice.iter().enumerate() {
+        buf[i] = byte;
+    }
+}
 
 fn main() {
     let mut console = Console::new();
 
     writeln!(console, "****************************************").unwrap();
     writeln!(console, "nfct_test application is installed").unwrap();
-    writeln!(console, "****************************************").unwrap();
 
-    // 1. Subscribe to a SELECTED CALLBACK
-    // 2. Configure Type 4 tag
-    // [_.] Enable Tag emulation (currently the tag is always activated)
-    // loop {
-    // 1. Allow Receive Buffer
-    // 2. Subscribe to RECEIVE CALLBACK
-    // 3. Allow TX buffer
-    // 4. Subscribe to TX CALLBACK
-    // }
+    // 1. Configure Type 4 tag
+    if NfcTag::configure(4) {
+        writeln!(console, " -- TAG CONFIGURED").unwrap();
+    }
+    // 2. Subscribe to a SELECTED CALLBACK
+    if NfcTag::selected() {
+        writeln!(console, " -- TAG SELECTED").unwrap();
+        // 0xfffff results in 1048575 / 13.56e6 = 77ms
+        NfcTag::set_framedelaymax(0xfffff);
+    }
+    /*
+    [_.] TODO: Enable Tag emulation (currently the tag is always activated)
+    needs field detection support in the driver level.
+    */
+    let mut rx_buf = [0; 64];
+    let mut unknown_cmd_cntr = 0;
+    loop {
+        NfcTag::receive(&mut rx_buf);
+        match rx_buf[0] {
+            0xe0 /* RATS */=> {
+                let mut answer_to_select = [0x05, 0x78, 0x80, 0xB1, 0x00];
+                let amount = answer_to_select.len();
+                NfcTag::transmit(&mut answer_to_select, amount);
+            }
+            0xc2 /* DESELECT */ => {
+                // Ignore the request
+                let mut command_error = [0x6A, 0x81];
+                let amount = command_error.len();
+                NfcTag::transmit(&mut command_error, amount);
+            }
+            0x02 | 0x03 /* APDU Prefix */ => {
+                let mut reply = [rx_buf[0], 0x90, 0x00];
+                let amount = reply.len();
+                NfcTag::transmit(&mut reply, amount);
+            }
+            _ => {
+                unknown_cmd_cntr += 1;
+            }
+        }
+        if unknown_cmd_cntr > 50 {
+            break;
+        }
+    }
+    writeln!(console, "****************************************").unwrap();
 }