update stm32wb linker to match new startup

hw/bsp/stm32wb/boards/stm32wb55nucleo/stm32wb55xx_flash_cm4.ld

@@ -3,21 +3,26 @@
 **
 **  File        : stm32wb55xx_flash_cm4.ld
 **
-**  Abstract    : System Workbench Minimal System calls file
+**  Author      : STM32CubeIDE
 **
-** 		          For more information about which c-functions
-**                need which of these lowlevel functions
-**                please consult the Newlib libc-manual
+**  Abstract    : Linker script for STM32WB55xx Device
+**                     1024Kbytes FLASH
+**                      128Kbytes RAM
 **
-**  Environment : System Workbench for MCU
+**                Set heap size, stack size and stack location according
+**                to application requirements.
 **
-**  Distribution: The file is distributed “as is,” without any warranty
+**                Set memory bank area and size if external memory is used.
+**
+**  Target      : STMicroelectronics STM32
+**
+**  Distribution: The file is distributed as is without any warranty
 **                of any kind.
 **
 *****************************************************************************
 ** @attention
 **
-** Copyright (c) 2019 STMicroelectronics.
+** Copyright (c) 2019-2022 STMicroelectronics.
 ** All rights reserved.
 **
 ** This software is licensed under terms that can be found in the LICENSE file
@@ -33,7 +38,7 @@ ENTRY(Reset_Handler)
 /* Highest address of the user mode stack */
 _estack = 0x20030000;    /* end of RAM */
 /* Generate a link error if heap and stack don't fit into RAM */
-_Min_Heap_Size = 0x400;      /* required amount of heap  */
+_Min_Heap_Size  = 0x400;    /* required amount of heap  */
 _Min_Stack_Size = 0x1000;   /* required amount of stack */
 
 /* Specify the memory areas */
@@ -81,14 +86,17 @@ SECTIONS
     . = ALIGN(4);
   } >FLASH
 
-  .ARM.extab   : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH
+  .ARM.extab :
+  {
+    *(.ARM.extab* .gnu.linkonce.armextab.*)
+  } >FLASH
   .ARM : {
     __exidx_start = .;
     *(.ARM.exidx*)
     __exidx_end = .;
   } >FLASH
 
-  .preinit_array     :
+  .preinit_array :
   {
     PROVIDE_HIDDEN (__preinit_array_start = .);
     KEEP (*(.preinit_array*))
@@ -124,7 +132,6 @@ SECTIONS
     _edata = .;        /* define a global symbol at data end */
   } >RAM1 AT> FLASH
 
-
   /* Uninitialized data section */
   . = ALIGN(4);
   .bss :
@@ -152,8 +159,6 @@ SECTIONS
     . = ALIGN(8);
   } >RAM1
 
-
-
   /* Remove information from the standard libraries */
   /DISCARD/ :
   {
@@ -163,7 +168,15 @@ SECTIONS
   }
 
   .ARM.attributes 0       : { *(.ARM.attributes) }
-   MAPPING_TABLE (NOLOAD) : { *(MAPPING_TABLE) } >RAM_SHARED
-   MB_MEM1 (NOLOAD)       : { *(MB_MEM1) } >RAM_SHARED
-   MB_MEM2 (NOLOAD)       : { _sMB_MEM2 = . ; *(MB_MEM2) ; _eMB_MEM2 = . ; } >RAM_SHARED
+  MAPPING_TABLE (NOLOAD) : { *(MAPPING_TABLE) } >RAM_SHARED
+  MB_MEM1 (NOLOAD)       : { *(MB_MEM1) } >RAM_SHARED
+
+  /* used by the startup to initialize .MB_MEM2 data */
+  _siMB_MEM2 = LOADADDR(.MB_MEM2);
+  .MB_MEM2 :
+  {
+    _sMB_MEM2 = . ;
+    *(MB_MEM2) ;
+    _eMB_MEM2 = . ;
+  } >RAM_SHARED AT> FLASH
 }

hw/bsp/stm32wb/family.c

@@ -184,8 +184,7 @@ void HardFault_Handler(void) {
   asm("bkpt 1");
 }
 
-// Required by __libc_init_array in startup code if we are compiling using
-// -nostdlib/-nostartfiles.
+// Required by __libc_init_array in startup code if we are compiling using -nostdlib/-nostartfiles.
+void _init(void);
 void _init(void) {
-
 }