some linker script updates to work even more properly for newlib i think

link.ld

@@ -14,17 +14,33 @@ SECTIONS {
     } > RAM
 
     .data : ALIGN(8) {
-        _data = .;
+        _data_start = .;
         *(.data*)
-        _edata = .;
+        _data_end = .;
     } > RAM
 
     .bss : ALIGN(8) {
-        _bss = .;
+        _bss_start = .;
         *(.bss*)
         *(COMMON)
-        _ebss = .;
+        _bss_end = .;
     } > RAM
 
+    .sdata : ALIGN(8) {
+        _sdata_start = .;
+        *(.sdata*)
+        _sdata_end = .;
+    } > RAM
+
+    .sbss : ALIGN(8) {
+        _sbss_start = .;
+        *(.sbss*)
+        _sbss_end = .;
+    } > RAM
+
+    __global_pointer$ = _sdata_start + ((_sdata_end - _sdata_start + _sbss_end - _sbss_start) / 2);
+
+    _heap_start = ALIGN(8);
+
     _stack_top = ORIGIN(RAM) + LENGTH(RAM);
 }