FWU: Add Generic Firmware Update framework support in BL1

Firmware update(a.k.a FWU) feature is part of the TBB architecture.
BL1 is responsible for carrying out the FWU process if platform
specific code detects that it is needed.

This patch adds support for FWU feature support in BL1 which is
included by enabling `TRUSTED_BOARD_BOOT` compile time flag.

This patch adds bl1_fwu.c which contains all the core operations
of FWU, which are; SMC handler, image copy, authentication, execution
and resumption. It also adds bl1.h introducing #defines for all
BL1 SMCs.

Following platform porting functions are introduced:

int bl1_plat_mem_check(uintptr_t mem_base, unsigned int mem_size,
unsigned int flags);
	This function can be used to add platform specific memory checks
	for the provided base/size for the given security state.
	The weak definition will invoke `assert()` and return -ENOMEM.

__dead2 void bl1_plat_fwu_done(void *cookie, void *reserved);
	This function can be used to initiate platform specific procedure
	to mark completion of the FWU process.
	The weak definition waits forever calling `wfi()`.

plat_bl1_common.c contains weak definitions for above functions.

FWU process starts when platform detects it and return the image_id
other than BL2_IMAGE_ID by using `bl1_plat_get_next_image_id()` in
`bl1_main()`.

NOTE: User MUST provide platform specific real definition for
bl1_plat_mem_check() in order to use it for Firmware update.

Change-Id: Ice189a0885d9722d9e1dd03f76cac1aceb0e25ed
diff --git a/plat/common/plat_bl1_common.c b/plat/common/plat_bl1_common.c
index 73362a1..aee9440 100644
--- a/plat/common/plat_bl1_common.c
+++ b/plat/common/plat_bl1_common.c
@@ -27,19 +27,24 @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
+
+#include <arch_helpers.h>
+#include <assert.h>
 #include <bl_common.h>
 #include <debug.h>
+#include <errno.h>
 #include <platform_def.h>
 
 /*
  * The following platform functions are weakly defined. They
- * are default implementations that allow BL1  compile in
+ * are default implementations that allow BL1 to compile in
  * absence of real definitions. The Platforms may override
  * with more complex definitions.
  */
 #pragma weak bl1_plat_get_next_image_id
 #pragma weak bl1_plat_set_ep_info
 #pragma weak bl1_plat_get_image_desc
+#pragma weak bl1_plat_fwu_done
 
 
 unsigned int bl1_plat_get_next_image_id(void)
@@ -63,3 +68,21 @@
 	static image_desc_t bl2_img_desc = BL2_IMAGE_DESC;
 	return &bl2_img_desc;
 }
+
+__dead2 void bl1_plat_fwu_done(void *cookie, void *rsvd_ptr)
+{
+	while (1)
+		wfi();
+}
+
+/*
+ * The Platforms must override with real definition.
+ */
+#pragma weak bl1_plat_mem_check
+
+int bl1_plat_mem_check(uintptr_t mem_base, unsigned int mem_size,
+		unsigned int flags)
+{
+	assert(0);
+	return -ENOMEM;
+}