Rework workaround for STM32H7 DTCM retention issue

Author: Igor-Misic

Bootloader/Adapters/Src/system_adapter.c

@@ -35,7 +35,14 @@
 #include "main.h"
 #include "system_adapter.h"
 
+#include "binary_update.h"
+
+extern __attribute__ ((section(".restart_info")))
+volatile bootInfo_S boot_info;
+
 void
 SystemAdapter_reset(void) {
+
+    boot_info.end = 0xFF; // Resolve known issue with STM32H7 MCUs. Memory must be written before reset to ensure data retention.
     HAL_NVIC_SystemReset();
 }

Bootloader/Inc/binary_update.h

@@ -41,9 +41,9 @@
 
 #pragma pack(push, 1)
 typedef struct bootInfo {
-    uint32_t jump_address;                  //!< Address for BL to jump
-    bool skip_bl_loop;                      //!< Flag to skip BL loop
-    uint8_t end; // FIXME: added here because after restart something is messing up with data in the structure and if there is an extra byte at the end it messes only with it
+    uint32_t jump_address;  //!< Address for BL to jump
+    bool skip_bl_loop;      //!< Flag to skip BL loop
+    uint8_t end;            //!< MCUs like the STM32H7 have issues preserving certain data unless an additional byte is written before reset.
 } bootInfo_S;
 #pragma pack(pop)
 

Bootloader/Src/binary_update.c

@@ -250,8 +250,6 @@ BinaryUpdate_finish(void) {
             break;
     }
 
-    boot_info.end = 0xFF;
-
     return success;
 }