Merge pull request #14277 from hugueskamba/hk_fix_apollo3_heap_stack_location

Apollo3: Fix run time error due to memory mapping

Author: 0xc0170

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/TOOLCHAIN_ARM_STD/AMA3B1KK.sct

@@ -1,7 +1,7 @@
 #! armclang -E --target=arm-arm-none-eabi -x c -mcpu=cortex-m4
 
 ;
-; Copyright (c) 2019-2020 SparkFun Electronics
+; Copyright (c) 2019-2021 SparkFun Electronics
 ; SPDX-License-Identifier: MIT
 ;
 ; Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -40,7 +40,18 @@
 #define MBED_RAM0_SIZE  0x100
 #define MBED_RAM1_START (MBED_RAM0_START + MBED_RAM0_SIZE)
 #define MBED_RAM1_SIZE  (MBED_RAM_SIZE - (MBED_RAM0_SIZE))
+; This section does not contain any symbols. It is only used for the linker
+; to calculate the size of the stack sections and assign values to stack
+; symbols later
+#define STACK_DUMMY_START (MBED_RAM1_START + MBED_RAM1_SIZE)
+#define STACK_DUMMY_SIZE 0x8
+#define Stack_Start (STACK_DUMMY_START - STACK_DUMMY_SIZE)
 #define Stack_Size MBED_CONF_TARGET_BOOT_STACK_SIZE
+; The heap dummy section is used to identify the beginning of available dynamic memory.
+#define HEAP_DUMMY_SIZE 0x8
+#define Heap_Start AlignExpr(+0, 16)
+#define Heap_Size (MBED_RAM_SIZE - RAM_FIXED_SIZE + MBED_RAM1_START - AlignExpr(ImageLimit(RW_IRAM1), 16) - HEAP_DUMMY_SIZE)
+
 #define RAM_FIXED_SIZE   (MBED_CONF_TARGET_BOOT_STACK_SIZE+MBED_RAM0_SIZE)
 
 
@@ -56,8 +67,8 @@ LR_IROM1 MBED_APP_START MBED_APP_SIZE {
   RW_IRAM1 MBED_RAM1_START MBED_RAM1_SIZE {
    .ANY (+RW +ZI)
   }
-  ARM_LIB_HEAP  AlignExpr(+0, 16)  EMPTY  (MBED_RAM_SIZE-RAM_FIXED_SIZE+MBED_RAM1_START-AlignExpr(ImageLimit(RW_IRAM1), 16))  {
+  ARM_LIB_HEAP Heap_Start EMPTY Heap_Size { ; Heap region growing up
   }
-  ARM_LIB_STACK MBED_RAM1_START+MBED_RAM1_SIZE EMPTY -Stack_Size { ; Stack region growing down
+  ARM_LIB_STACK Stack_Start EMPTY -Stack_Size { ; Stack region growing down
   }
 }