Merge pull request ARMmbed#14466 from harmut01/baremetal_gigadevice

GigaDevice: Add bare metal support for targets

Author: adbridge

targets/TARGET_GigaDevice/TARGET_GD32F30X/TARGET_GD32F307VG/device/TOOLCHAIN_ARM_MICRO/gd32f307vg.sct

@@ -4,11 +4,19 @@
 ; *****
 
 #if !defined(MBED_APP_START)
-  #define MBED_APP_START 0x08000000
+  #define MBED_APP_START            0x08000000
 #endif
 
 #if !defined(MBED_APP_SIZE)
-  #define MBED_APP_SIZE 0x100000
+  #define MBED_APP_SIZE             0x100000
+#endif
+
+#if !defined(MBED_RAM_START)
+  #define MBED_RAM_START            0x20000000
+#endif
+
+#if !defined(MBED_RAM_SIZE)
+  #define MBED_RAM_SIZE             0x00018000
 #endif
 
 #if !defined(MBED_CONF_TARGET_BOOT_STACK_SIZE)
@@ -19,7 +27,15 @@
 #  endif
 #endif
 
-#define Stack_Size MBED_CONF_TARGET_BOOT_STACK_SIZE
+
+; 84 vectors (16 core + 68 peripheral) * 4 bytes = 336 bytes to reserve (0x150)
+#define VECTOR_SIZE                 0x150
+
+#define Stack_Size                  MBED_CONF_TARGET_BOOT_STACK_SIZE
+
+#define RAM_FIXED_SIZE              (Stack_Size+VECTOR_SIZE)
+
+#define MBED_RAM1_START (MBED_RAM_START+VECTOR_SIZE)
 
 LR_IROM1 MBED_APP_START MBED_APP_SIZE  {    ; load region size_region (1024K)
 
@@ -30,11 +46,14 @@ LR_IROM1 MBED_APP_START MBED_APP_SIZE  {    ; load region size_region (1024K)
   }
 
   ; 84 vectors (16 core + 68 peripheral) * 4 bytes = 336 bytes to reserve (0x150)
-  RW_IRAM1 (0x20000000+0x150) (0x18000-0x150-Stack_Size)  {  ; RW data
+  RW_IRAM1 (MBED_RAM_START+VECTOR_SIZE) (MBED_RAM_SIZE-RAM_FIXED_SIZE)  {  ; RW data
    .ANY (+RW +ZI)
   }
 
-  ARM_LIB_STACK (0x20000000+0x18000) EMPTY -Stack_Size { ; stack
+  ARM_LIB_HEAP  AlignExpr(+0, 16)  EMPTY  (MBED_RAM_SIZE-RAM_FIXED_SIZE+MBED_RAM1_START-AlignExpr(ImageLimit(RW_IRAM1), 16))  { ; Heap region growing up
+  }
+
+  ARM_LIB_STACK (MBED_RAM_START+MBED_RAM_SIZE) EMPTY -Stack_Size { ; Stack region growing down
   }
 }