From f390e9a7d1c958b63861c2100783249912e9f067 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Wed, 23 Jul 2014 19:12:22 -0600
Subject: [PATCH] corecom_serial: add CRC for kernel

---
 artiq/devices/corecom_serial.py |  6 +++---
 soc/runtime/main.c              | 11 ++++++++++-
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/artiq/devices/corecom_serial.py b/artiq/devices/corecom_serial.py
index 84ee55c79..1b45b3fe6 100644
--- a/artiq/devices/corecom_serial.py
+++ b/artiq/devices/corecom_serial.py
@@ -1,4 +1,4 @@
-import os, termios, struct
+import os, termios, struct, zlib
 from enum import Enum
 
 from artiq.language import units
@@ -78,8 +78,8 @@ class CoreCom:
 		return Environment(ref_period*units.ps)
 
 	def run(self, kcode):
-		_write_exactly(self.port, struct.pack(">lbl",
-			0x5a5a5a5a, _MsgType.LOAD_KERNEL.value, len(kcode)))
+		_write_exactly(self.port, struct.pack(">lblL",
+			0x5a5a5a5a, _MsgType.LOAD_KERNEL.value, len(kcode), zlib.crc32(kcode)))
 		_write_exactly(self.port, kcode)
 		(reply, ) = struct.unpack("b", _read_exactly(self.port, 1))
 		if reply != 0x4f:
diff --git a/soc/runtime/main.c b/soc/runtime/main.c
index a31472f38..2714c1255 100644
--- a/soc/runtime/main.c
+++ b/soc/runtime/main.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
+#include <crc.h>
 
 #include <irq.h>
 #include <uart.h>
@@ -81,6 +82,7 @@ static void send_sync(void)
 static int ident_and_download_kernel(void *buffer, int maxlength)
 {
 	int length;
+	unsigned int crc;
 	int i;
 	char msgtype;
 	unsigned char *_buffer = buffer;
@@ -93,10 +95,17 @@ static int ident_and_download_kernel(void *buffer, int maxlength)
 			send_int(1000000000000LL/identifier_frequency_read()); /* RTIO clock period in picoseconds */
 		} else if(msgtype == MSGTYPE_LOAD_KERNEL) {
 			length = receive_int();
-			if(length > maxlength)
+			if(length > maxlength) {
+				send_char(0x4c); /* Incorrect length */
 				return -1;
+			}
+			crc = receive_int();
 			for(i=0;i<length;i++)
 				_buffer[i] = receive_char();
+			if(crc32(buffer, length) != crc) {
+				send_char(0x43); /* CRC failed */
+				return -1;
+			}
 			send_char(0x4f); /* kernel reception OK */
 			return length;
 		} else