Openblt to dfu jump fixed (#4367)

* OpenBLT: supress "target 'startup_xxxxxx.o' given more than once in the same rule" warning

* OpenBLT: check for DFU request, do not ignore dead beef

firmware/hw_layer/openblt/openblt.mk

@@ -85,7 +85,6 @@ PROJ_FILES += $(PROJECT_DIR)/hw_layer/openblt/led.h
 
 # CPU-dependent sources
 ifeq ($(PROJECT_CPU),ARCH_STM32F4)
-    PROJ_FILES += $(PROJECT_DIR)/hw_layer/ports/stm32/stm32f4/openblt/lib/startup_stm32f429xx.s
 	# Collect bootloader port files
 	PROJ_FILES += $(wildcard $(OPENBLT_TRGT_DIR)/Source/ARMCM4_STM32F4/*.c)
 	PROJ_FILES += $(wildcard $(OPENBLT_TRGT_DIR)/Source/ARMCM4_STM32F4/*.h)
@@ -97,7 +96,6 @@ ifeq ($(PROJECT_CPU),ARCH_STM32F4)
 	# Port specific options
 	PORTFLAGS  += -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16
 else ifeq ($(PROJECT_CPU),ARCH_STM32F7)
-    PROJ_FILES += $(PROJECT_DIR)/hw_layer/ports/stm32/stm32f7/openblt/lib/startup_stm32f767xx.s
 	# Collect bootloader port files
 	PROJ_FILES += $(wildcard $(OPENBLT_TRGT_DIR)/Source/ARMCM7_STM32F7/*.c)
 	PROJ_FILES += $(wildcard $(OPENBLT_TRGT_DIR)/Source/ARMCM7_STM32F7/*.h)
@@ -109,7 +107,6 @@ else ifeq ($(PROJECT_CPU),ARCH_STM32F7)
 	# Port specific options
 	PORTFLAGS   = -mcpu=cortex-m7 -mthumb -mfloat-abi=hard -mfpu=fpv5-sp-d16
 else ifeq ($(PROJECT_CPU),ARCH_STM32H7)
-    # todo: do we need startup_stmXX.s here?
 	# Collect bootloader port files
 	PROJ_FILES += $(wildcard $(OPENBLT_TRGT_DIR)/Source/ARMCM7_STM32H7/*.c)
 	PROJ_FILES += $(wildcard $(OPENBLT_TRGT_DIR)/Source/ARMCM7_STM32H7/*.h)

firmware/hw_layer/ports/stm32/stm32f4/openblt/lib/startup_stm32f429xx.s

@@ -59,6 +59,16 @@ defined in linker script */
   .weak  Reset_Handler
   .type  Reset_Handler, %function
 Reset_Handler: 
+  // Clive Two.Zero is the God of ST community forum
+  // Device specific, if in doubt RTFM
+  LDR R0, =0x2001FFF0 // End of SRAM for your CPU
+  LDR R1, =0xDEADBEEF // magic value
+  LDR R2, [R0, #0]
+  STR R0, [R0, #0] // Invalidate
+  CMP R2, R1
+  BEQ UseDFU
+  // DFU bootloader not needed, continue with OpenBLT
+
   ldr   sp, =_estack       /* set stack pointer */
  
 /* Copy the data segment initializers from flash to SRAM */  
@@ -98,6 +108,12 @@ LoopFillZerobss:
   bx  lr    
 .size  Reset_Handler, .-Reset_Handler
 
+UseDFU:
+  // AN2606 Application note
+  // STM32 microcontroller system memory boot mode
+.include "../../dfu_init.h"
+  BX R0 // this jumps to DFU bootloader
+
 /**
  * @brief  This is the code that gets called when the processor receives an 
  *         unexpected interrupt.  This simply enters an infinite loop, preserving

firmware/hw_layer/ports/stm32/stm32f7/openblt/lib/startup_stm32f767xx.s

@@ -75,6 +75,16 @@ defined in linker script */
   .weak  Reset_Handler
   .type  Reset_Handler, %function
 Reset_Handler:  
+  // Clive Two.Zero is the God of ST community forum
+  // Device specific, if in doubt RTFM
+  LDR R0, =0x2001FFF0 // End of SRAM for your CPU
+  LDR R1, =0xDEADBEEF // magic value
+  LDR R2, [R0, #0]
+  STR R0, [R0, #0] // Invalidate
+  CMP R2, R1
+  BEQ UseDFU
+  // DFU bootloader not needed, continue with OpenBLT
+
   ldr   sp, =_estack      /* set stack pointer */
 
 /* Copy the data segment initializers from flash to SRAM */  
@@ -114,6 +124,12 @@ LoopFillZerobss:
   bx  lr    
 .size  Reset_Handler, .-Reset_Handler
 
+UseDFU:
+  // AN2606 Application note
+  // STM32 microcontroller system memory boot mode
+.include "../../dfu_init.h"
+  BX R0 // this jumps to DFU bootloader
+
 /**
  * @brief  This is the code that gets called when the processor receives an 
  *         unexpected interrupt.  This simply enters an infinite loop, preserving

firmware/hw_layer/ports/stm32/stm32h7/openblt/lib/startup_stm32h743xx.s

@@ -59,6 +59,16 @@ defined in linker script */
   .weak  Reset_Handler
   .type  Reset_Handler, %function
 Reset_Handler:  
+  // Clive Two.Zero is the God of ST community forum
+  // Device specific, if in doubt RTFM
+  LDR R0, =0x2001FFF0 // End of SRAM for your CPU
+  LDR R1, =0xDEADBEEF // magic value
+  LDR R2, [R0, #0]
+  STR R0, [R0, #0] // Invalidate
+  CMP R2, R1
+  BEQ UseDFU
+  // DFU bootloader not needed, continue with OpenBLT
+
   ldr   sp, =_estack      /* set stack pointer */
 
 /* Copy the data segment initializers from flash to SRAM */  
@@ -98,6 +108,12 @@ LoopFillZerobss:
   bx  lr    
 .size  Reset_Handler, .-Reset_Handler
 
+UseDFU:
+  // AN2606 Application note
+  // STM32 microcontroller system memory boot mode
+.include "../../dfu_init.h"
+  BX R0 // this jumps to DFU bootloader
+
 /**
  * @brief  This is the code that gets called when the processor receives an 
  *         unexpected interrupt.  This simply enters an infinite loop, preserving