Fix _ram_start and _ram_end order

Author: Norbert Fabritius

cortex-m-rt/link.x.in

@@ -60,9 +60,9 @@ PROVIDE(__pre_init = DefaultPreInit);
 /* # Sections */
 SECTIONS
 {
-  PROVIDE(_ram_start = ORIGIN(RAM) + LENGTH(RAM));
-  PROVIDE(_ram_end = ORIGIN(RAM));
-  PROVIDE(_stack_start = _ram_start);
+  PROVIDE(_ram_start = ORIGIN(RAM));
+  PROVIDE(_ram_end = ORIGIN(RAM) + LENGTH(RAM));
+  PROVIDE(_stack_start = _ram_end);
 
   /* ## Sections in FLASH */
   /* ### Vector table */

cortex-m-rt/src/lib.rs

@@ -517,8 +517,8 @@ cfg_global_asm! {
     // If enabled, initialize RAM with zeros. This is normally not necessary but might be required
     // on custom hardware.
     #[cfg(feature = "zero-init-ram")]
-    "ldr r0, =_ram_end
-     ldr r1, =_ram_start
+    "ldr r0, =_ram_start
+     ldr r1, =_ram_end
      movs r2, #0
      0:
      cmp r1, r0