Add descriptor based image management support in BL1

As of now BL1 loads and execute BL2 based on hard coded information
provided in BL1. But due to addition of support for upcoming Firmware
Update feature, BL1 now require more flexible approach to load and
run different images using information provided by the platform.

This patch adds new mechanism to load and execute images based on
platform provided image id's. BL1 now queries the platform to fetch
the image id of the next image to be loaded and executed. In order
to achieve this, a new struct image_desc_t was added which holds the
information about images, such as: ep_info and image_info.

This patch introduces following platform porting functions:

unsigned int bl1_plat_get_next_image_id(void);
	This is used to identify the next image to be loaded
	and executed by BL1.

struct image_desc *bl1_plat_get_image_desc(unsigned int image_id);
	This is used to retrieve the image_desc for given image_id.

void bl1_plat_set_ep_info(unsigned int image_id,
struct entry_point_info *ep_info);
	This function allows platforms to update ep_info for given
	image_id.

The plat_bl1_common.c file provides default weak implementations of
all above functions, the `bl1_plat_get_image_desc()` always return
BL2 image descriptor, the `bl1_plat_get_next_image_id()` always return
BL2 image ID and `bl1_plat_set_ep_info()` is empty and just returns.
These functions gets compiled into all BL1 platforms by default.

Platform setup in BL1, using `bl1_platform_setup()`, is now done
_after_ the initialization of authentication module. This change
provides the opportunity to use authentication while doing the
platform setup in BL1.

In order to store secure/non-secure context, BL31 uses percpu_data[]
to store context pointer for each core. In case of BL1 only the
primary CPU will be active hence percpu_data[] is not required to
store the context pointer.

This patch introduce bl1_cpu_context[] and bl1_cpu_context_ptr[] to
store the context and context pointers respectively. It also also
re-defines cm_get_context() and cm_set_context() for BL1 in
bl1/bl1_context_mgmt.c.

BL1 now follows the BL31 pattern of using SP_EL0 for the C runtime
environment, to support resuming execution from a previously saved
context.

NOTE: THE `bl1_plat_set_bl2_ep_info()` PLATFORM PORTING FUNCTION IS
      NO LONGER CALLED BY BL1 COMMON CODE. PLATFORMS THAT OVERRIDE
      THIS FUNCTION MAY NEED TO IMPLEMENT `bl1_plat_set_ep_info()`
      INSTEAD TO MAINTAIN EXISTING BEHAVIOUR.

Change-Id: Ieee4c124b951c2e9bc1c1013fa2073221195d881
diff --git a/include/common/bl_common.h b/include/common/bl_common.h
index d8741c9..bedd496 100644
--- a/include/common/bl_common.h
+++ b/include/common/bl_common.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -59,11 +59,41 @@
 #define ENTRY_POINT_INFO_PC_OFFSET	0x08
 #define ENTRY_POINT_INFO_ARGS_OFFSET	0x18
 
-#define PARAM_EP_SECURITY_MASK    0x1
+/* The following are used to set/get image attributes. */
+#define EXECUTABLE			(0x1)
+#define NON_EXECUTABLE			(0x0)
+#define PARAM_EP_EXECUTE_MASK		(0x1)
+#define PARAM_EP_EXECUTE_SHIFT		(0x1)
+#define PARAM_EP_SECURITY_MASK		(0x1)
+#define PARAM_EP_SECURITY_SHIFT		(0x0)
+
 #define GET_SECURITY_STATE(x) (x & PARAM_EP_SECURITY_MASK)
 #define SET_SECURITY_STATE(x, security) \
 			((x) = ((x) & ~PARAM_EP_SECURITY_MASK) | (security))
 
+#define GET_EXEC_STATE(x)    \
+    (((x) >> PARAM_EP_EXECUTE_SHIFT) & PARAM_EP_EXECUTE_MASK)
+
+#define SET_EXEC_STATE(x)    \
+    (((x) & PARAM_EP_EXECUTE_MASK) << PARAM_EP_EXECUTE_SHIFT)
+
+#define GET_SEC_STATE(x)    \
+    (((x) >> PARAM_EP_SECURITY_SHIFT) & PARAM_EP_SECURITY_MASK)
+
+#define SET_SEC_STATE(x)    \
+    (((x) & PARAM_EP_SECURITY_MASK) << PARAM_EP_SECURITY_SHIFT)
+
+/*
+ * The following are used for image state attributes.
+ * Image can only be in one of the following state.
+ */
+#define IMAGE_STATE_RESET			0
+#define IMAGE_STATE_COPIED			1
+#define IMAGE_STATE_COPYING			2
+#define IMAGE_STATE_AUTHENTICATED		3
+#define IMAGE_STATE_EXECUTED			4
+#define IMAGE_STATE_INTERRUPTED			5
+
 #define EP_EE_MASK	0x2
 #define EP_EE_LITTLE	0x0
 #define EP_EE_BIG	0x2
@@ -82,6 +112,8 @@
 
 #define VERSION_1		0x01
 
+#define INVALID_IMAGE_ID		(0xFFFFFFFF)
+
 #define SET_PARAM_HEAD(_p, _type, _ver, _attr) do { \
 	(_p)->h.type = (uint8_t)(_type); \
 	(_p)->h.version = (uint8_t)(_ver); \
@@ -196,8 +228,24 @@
 	param_header_t h;
 	uintptr_t image_base;   /* physical address of base of image */
 	uint32_t image_size;    /* bytes read from image file */
+	uint32_t copied_size;	/* image size copied in blocks */
 } image_info_t;
 
+/*****************************************************************************
+ * The image descriptor struct definition.
+ *****************************************************************************/
+typedef struct image_desc {
+	/* Contains unique image id for the image. */
+	unsigned int image_id;
+	image_info_t image_info;
+	entry_point_info_t ep_info;
+	/*
+	 * This member contains Image state information.
+	 * Refer IMAGE_STATE_XXX defined above.
+	 */
+	unsigned int state;
+} image_desc_t;
+
 /*******************************************************************************
  * This structure represents the superset of information that can be passed to
  * BL31 e.g. while passing control to it from BL2. The BL32 parameters will be