Fix VTOR relocate, add bootloader makefile handling

ports/stm32f4/Makefile

@@ -90,6 +90,10 @@ else
   ### CFLAGS += -flto
 endif
 
+ifndef BOOTLOADER_OFFSET
+	BOOTLOADER_OFFSET := 0x8000000
+endif
+
 C_DEFS = -DMCU_PACKAGE=$(MCU_PACKAGE) -DUSE_HAL_DRIVER -DUSE_FULL_LL_DRIVER -D$(CMSIS_MCU)
 
 CFLAGS += $(INC) -Werror -Wall -std=gnu11 -nostdlib $(BASE_CFLAGS) $(C_DEFS) $(CFLAGS_MOD) $(COPT)
@@ -257,7 +261,7 @@ $(BUILD)/firmware.hex: $(BUILD)/firmware.elf
 
 $(BUILD)/firmware.uf2: $(BUILD)/firmware.hex
 	$(ECHO) "Create $@"
-	$(PYTHON3) $(TOP)/tools/uf2/utils/uf2conv.py -f 0x57755a57 -b 0x08010000 -c -o "$(BUILD)/firmware.uf2" $^
+	$(PYTHON3) $(TOP)/tools/uf2/utils/uf2conv.py -f 0x57755a57 -b $(BOOTLOADER_OFFSET) -c -o "$(BUILD)/firmware.uf2" $^
 
 include $(TOP)/py/mkrules.mk
 

ports/stm32f4/boards/meowbit_v121/mpconfigboard.h

@@ -37,6 +37,7 @@
 
 #define BOARD_OSC_DIV 12
 #define BOARD_NO_VBUS_SENSE
+#define BOARD_VTOR_DEFER //Leave VTOR relocation to bootloader
 
 // On-board flash
 #define SPI_FLASH_MOSI_PIN          (&pin_PB15)

ports/stm32f4/boards/meowbit_v121/mpconfigboard.mk

@@ -9,6 +9,8 @@ EXTERNAL_FLASH_DEVICE_COUNT = 1
 EXTERNAL_FLASH_DEVICES = W25Q16JV_IQ
 LONGINT_IMPL = MPZ
 
+BOOTLOADER_OFFSET = 0x8010000
+
 # INTERNAL_FLASH_FILESYSTEM = 1
 # LONGINT_IMPL = NONE
 

ports/stm32f4/system_stm32f4xx.c

@@ -1,3 +1,27 @@
+/*
+ * Taken from ST Cube library and modified.  See below for original header.
+ * 
+ * Modifications copyright (c) 2019 Lucian Copeland for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
 /**
   ******************************************************************************
   * @file    system_stm32f4xx.c
@@ -63,6 +87,7 @@
 
 
 #include "stm32f4xx.h"
+#include "py/mpconfig.h"
 
 #if !defined  (HSE_VALUE) 
   #define HSE_VALUE    ((uint32_t)25000000) /*!< Default value of the External oscillator in Hz */
@@ -193,10 +218,12 @@ void SystemInit(void)
 #endif /* DATA_IN_ExtSRAM || DATA_IN_ExtSDRAM */
 
   /* Configure the Vector Table location add offset address ------------------*/
-#ifdef VECT_TAB_SRAM
+#if !defined(BOARD_VTOR_DEFER) //only set VTOR if the bootloader hasn't already
+  #ifdef VECT_TAB_SRAM
     SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
-#else
+  #else
     SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
+  #endif
 #endif
 }