From e0e41983582e3a9d0ff18440b9b51c3e654629cd Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Tue, 15 Dec 2020 18:00:22 +1100
Subject: [PATCH] AP_Bootloader: fixed can bootloader with old UAVCAN GUI tool

the part that was failing was the write of the leading words. That
part is not actually needed in this bootloader as we use a CRC before
running, so remove it, which fixes the old windows GUI tool.

This also saves some memory and flash
---
 Tools/AP_Bootloader/can.cpp | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/Tools/AP_Bootloader/can.cpp b/Tools/AP_Bootloader/can.cpp
index 175206c590..e70173d9c5 100644
--- a/Tools/AP_Bootloader/can.cpp
+++ b/Tools/AP_Bootloader/can.cpp
@@ -71,7 +71,6 @@ static uint8_t node_id_allocation_transfer_id;
 static uavcan_protocol_NodeStatus node_status;
 static uint32_t send_next_node_id_allocation_request_at_ms;
 static uint8_t node_id_allocation_unique_id_offset;
-static uint32_t app_first_words[8];
 
 static struct {
     uint64_t ofs;
@@ -226,12 +225,7 @@ static void handle_file_read_response(CanardInstance* ins, CanardRxTransfer* tra
         flash_func_erase_sector(fw_update.sector+1);
     }
     for (uint16_t i=0; i<len/4; i++) {
-        if (fw_update.sector == 0 && (fw_update.ofs+i*4) < sizeof(app_first_words)) {
-            // keep first word aside, to be flashed last
-            app_first_words[i] = buf32[i];
-        } else {
-            flash_write_buffer(fw_update.ofs+i*4, &buf32[i], 1);
-        }
+        flash_write_buffer(fw_update.ofs+i*4, &buf32[i], 1);
     }
     fw_update.ofs += len;
     fw_update.sector_ofs += len;
@@ -241,8 +235,6 @@ static void handle_file_read_response(CanardInstance* ins, CanardRxTransfer* tra
     }
     if (len < UAVCAN_PROTOCOL_FILE_READ_RESPONSE_DATA_MAX_LENGTH) {
         fw_update.node_id = 0;
-        // now flash the first word
-        flash_write_buffer(0, app_first_words, ARRAY_SIZE(app_first_words));
         flash_write_flush();
         if (can_check_firmware()) {
             jump_to_app();
@@ -265,8 +257,6 @@ static void handle_begin_firmware_update(CanardInstance* ins, CanardRxTransfer*
         return;
     }
 
-    memset(app_first_words, 0xff, sizeof(app_first_words));
-
     if (fw_update.node_id == 0) {
         uint32_t offset = 0;
         canardDecodeScalar(transfer, 0, 8, false, (void*)&fw_update.node_id);