System Calls cleanup, multiple Processes and context switch

[cortex-from-scratch] / link.ld

diff --git a/link.ld b/link.ld
index 1f6b5f6..63f173d 100644 (file)
--- a/link.ld
+++ b/link.ld
@@ -1,4 +1,28 @@
-/* */
+/* (CC-BY-NC-SA) ROBIN KRENS - ROBIN @ ROBINKRENS.NL
+ * 
+ * $LOG$
+ * 2019/7/20 - ROBIN KRENS     
+ * Initial version 
+ * 
+ * $DESCRIPTION$
+ * Linker file for Cortex-M3 STM32 based boards
+ * Boards have similar FLASH and SRAM ORIGINs
+ * LENGTHs differs of course.
+ * 
+ * _start flag is the first procedure to be 
+ * executed (linked to beginning of FLASH at 
+ * 0x08000000). The procedure should do some
+ * basic things, such as set up the stack and
+ * reset and hard fault handler (see start.asm)
+ * *
+ * _endofbss flag is used to calculate the end 
+ * of .bss and the start of (a possible) kernel
+ * heap
+ *
+ * */
+
+KHEAP_SIZE = 0x100; 
+
 MEMORY
 {
        FLASH (xr) : ORIGIN = 0x08000000, LENGTH = 512K
@@ -14,16 +38,23 @@ SECTIONS
        {
                /* (.vector_table */
                *(.text)
-               *(.rodata)
+               *(.rodata) 
+               data_lma = .;
        }
         . = 0x20000000;        
-       .data :  
+       data_vma = .;
+       .data : AT (data_lma)
        {
                *(.data)
        } 
+       data_end = .;
        .bss : ALIGN(4) 
        {
                *(.bss)
        }
                _endofbss = .;  
+       _beginofheap = .;
+       . = . + KHEAP_SIZE;
+       . = ALIGN(8);
+       _endofheap = .;
 }