Make the memory layout more flexible

Currently the platform code gets to define the base address of each
boot loader image. However, the linker scripts couteract this
flexibility by enforcing a fixed overall layout of the different
images. For example, they require that the BL3-1 image sits below
the BL2 image. Choosing BL3-1 and BL2 base addresses in such a way
that it violates this constraint makes the build fail at link-time.

This patch requires the platform code to now define a limit address
for each image. The linker scripts check that the image fits within
these bounds so they don't rely anymore on the position of a given
image in regard to the others.

Fixes ARM-software/tf-issues#163

Change-Id: I8c108646825da19a6a8dfb091b613e1dd4ae133c
diff --git a/plat/fvp/platform.h b/plat/fvp/platform.h
index ff87cf8..7fdbf81 100644
--- a/plat/fvp/platform.h
+++ b/plat/fvp/platform.h
@@ -237,21 +237,29 @@
 
 /*******************************************************************************
  * BL1 specific defines.
- * BL1 RW data is relocated from ROM to RAM at runtime so we need 2 base
+ * BL1 RW data is relocated from ROM to RAM at runtime so we need 2 sets of
  * addresses.
  ******************************************************************************/
 #define BL1_RO_BASE			TZROM_BASE
+#define BL1_RO_LIMIT			(TZROM_BASE + TZROM_SIZE)
 #define BL1_RW_BASE			TZRAM_BASE
+#define BL1_RW_LIMIT			BL31_BASE
 
 /*******************************************************************************
  * BL2 specific defines.
  ******************************************************************************/
 #define BL2_BASE			(TZRAM_BASE + TZRAM_SIZE - 0xc000)
+#define BL2_LIMIT			(TZRAM_BASE + TZRAM_SIZE)
 
 /*******************************************************************************
  * BL31 specific defines.
  ******************************************************************************/
 #define BL31_BASE			(TZRAM_BASE + 0x6000)
+#if TSP_RAM_LOCATION_ID == TSP_IN_TZRAM
+#define BL31_LIMIT			BL32_BASE
+#elif TSP_RAM_LOCATION_ID == TSP_IN_TZDRAM
+#define BL31_LIMIT			BL2_BASE
+#endif
 
 /*******************************************************************************
  * BL32 specific defines.