From 92ce4da1158aabd1a45d3a5044a5e5fd7bac3c41 Mon Sep 17 00:00:00 2001
From: Fredrik Thulin <fredrik@thulin.net>
Date: Fri, 27 May 2016 15:56:16 +0200
Subject: DFU working - but no signature validation for now.

---
 projects/bootloader/dfu.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 projects/bootloader/dfu.c

(limited to 'projects/bootloader/dfu.c')

diff --git a/projects/bootloader/dfu.c b/projects/bootloader/dfu.c
new file mode 100644
index 0000000..231e388
--- /dev/null
+++ b/projects/bootloader/dfu.c
@@ -0,0 +1,106 @@
+/*
+ * dfu.c
+ * ------------
+ * Receive new firmware from MGMT UART and write it to STM32 internal flash.
+ *
+ * Copyright (c) 2016, NORDUnet A/S All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the NORDUnet nor the names of its contributors may
+ *   be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "dfu.h"
+#include "stm-led.h"
+#include "stm-uart.h"
+#include "stm-flash.h"
+
+#include <string.h>
+
+extern uint32_t update_crc(uint32_t crc, uint8_t *buf, int len);
+
+
+int dfu_receive_firmware(void)
+{
+    uint32_t filesize = 0, crc = 0, my_crc = 0, counter = 0;
+    uint32_t offset = DFU_FIRMWARE_ADDR, n = DFU_UPLOAD_CHUNK_SIZE;
+    uint32_t buf[DFU_UPLOAD_CHUNK_SIZE / 4];
+
+    uart_send_string2(STM_UART_MGMT, (char *) "\r\nOK, bootloader waiting for new firmware\r\n");
+
+    /* Read file size (4 bytes) */
+    uart_receive_bytes(STM_UART_MGMT, (void *) &filesize, 4, 1000);
+    if (filesize < 512 || filesize > DFU_FIRMWARE_END_ADDR - DFU_FIRMWARE_ADDR) {
+	return -1;
+    }
+
+    HAL_FLASH_Unlock();
+
+    while (filesize) {
+	/* By initializing buf to the same value that erased flash has (0xff), we don't
+	 * have to try and be smart when writing the last page of data to the memory.
+	 */
+	memset(buf, 0xffffffff, sizeof(buf));
+
+	if (filesize < n) {
+	    n = filesize;
+	}
+
+	if (uart_receive_bytes(STM_UART_MGMT, (void *) &buf, n, 1000) != HAL_OK) {
+	    return -2;
+	}
+	filesize -= n;
+
+	/* After reception of a chunk but before ACKing we have "all" the time in the world to
+	 * calculate CRC and write it to flash.
+	 */
+	my_crc = update_crc(my_crc, (uint8_t *) buf, n);
+	stm_flash_write32(offset, buf, sizeof(buf) / 4);
+	offset += DFU_UPLOAD_CHUNK_SIZE;
+
+	/* ACK this chunk by sending the current chunk counter (4 bytes) */
+	counter++;
+	uart_send_bytes(STM_UART_MGMT, (void *) &counter, 4);
+	led_toggle(LED_BLUE);
+    }
+
+    HAL_FLASH_Lock();
+
+    /* The sending side will now send it's calculated CRC-32 */
+    uart_receive_bytes(STM_UART_MGMT, (void *) &crc, 4, 1000);
+    if (crc == my_crc) {
+	uart_send_string2(STM_UART_MGMT, (char *) "\r\nSuccess\r\n");
+	return 0;
+    }
+
+    led_on(LED_RED);
+    led_on(LED_YELLOW);
+
+    /* Better to erase the known bad firmware */
+    stm_flash_erase_sectors(DFU_FIRMWARE_ADDR, DFU_FIRMWARE_END_ADDR);
+
+    led_off(LED_YELLOW);
+
+    return 0;
+}
-- 
cgit v1.2.3