juno: Move BL3-1 arguments from normal DRAM to trusted RAM

On Juno, BL3-1 arguments used to sit at the beginning of the normal
DRAM. This patch moves them in trusted RAM. BL2 now allocates them
as a platform-specific static variable. BL3-1 then copies them
internally before the MMU is enabled.

Change-Id: I5cf526edfab5b49925b685092ff78506a5882f49

plat/juno/bl2_plat_setup.c

@@ -76,11 +76,9 @@ __attribute__ ((aligned(PLATFORM_CACHE_LINE_SIZE),
 		section("tzfw_coherent_mem")));
 
 /*******************************************************************************
- * Reference to structures which holds the arguments which need to be passed
- * to BL31
+ * Structure which holds the arguments which need to be passed to BL3-1
  ******************************************************************************/
-static bl31_params_t *bl2_to_bl31_params;
-static entry_point_info_t *bl31_ep_info;
+static bl2_to_bl31_params_mem_t bl31_params_mem;
 
 meminfo_t *bl2_plat_sec_mem_layout(void)
 {
@@ -98,46 +96,41 @@ meminfo_t *bl2_plat_sec_mem_layout(void)
  ******************************************************************************/
 bl31_params_t *bl2_plat_get_bl31_params(void)
 {
-	bl2_to_bl31_params_mem_t *bl31_params_mem;
+	bl31_params_t *bl2_to_bl31_params;
 
 	/*
-	 * Allocate the memory for all the arguments that needs to
-	 * be passed to BL31
+	 * Initialise the memory for all the arguments that needs to
+	 * be passed to BL3-1
 	 */
-	bl31_params_mem = (bl2_to_bl31_params_mem_t *)PARAMS_BASE;
-	memset((void *)PARAMS_BASE, 0, sizeof(bl2_to_bl31_params_mem_t));
+	memset(&bl31_params_mem, 0, sizeof(bl2_to_bl31_params_mem_t));
 
 	/* Assign memory for TF related information */
-	bl2_to_bl31_params = &bl31_params_mem->bl31_params;
+	bl2_to_bl31_params = &bl31_params_mem.bl31_params;
 	SET_PARAM_HEAD(bl2_to_bl31_params, PARAM_BL31, VERSION_1, 0);
 
-	/* Fill BL31 related information */
-	bl31_ep_info = &bl31_params_mem->bl31_ep_info;
-	bl2_to_bl31_params->bl31_image_info = &bl31_params_mem->bl31_image_info;
+	/* Fill BL3-1 related information */
+	bl2_to_bl31_params->bl31_image_info = &bl31_params_mem.bl31_image_info;
 	SET_PARAM_HEAD(bl2_to_bl31_params->bl31_image_info, PARAM_IMAGE_BINARY,
 		VERSION_1, 0);
 
-	/* Fill BL32 related information if it exists */
-	if (BL32_BASE) {
-		bl2_to_bl31_params->bl32_ep_info =
-			&bl31_params_mem->bl32_ep_info;
-		SET_PARAM_HEAD(bl2_to_bl31_params->bl32_ep_info,
-			PARAM_EP, VERSION_1, 0);
-		bl2_to_bl31_params->bl32_image_info =
-			&bl31_params_mem->bl32_image_info;
-		SET_PARAM_HEAD(bl2_to_bl31_params->bl32_image_info,
-			PARAM_IMAGE_BINARY,
-			VERSION_1, 0);
-	}
+	/* Fill BL3-2 related information if it exists */
+#if BL32_BASE
+	bl2_to_bl31_params->bl32_ep_info = &bl31_params_mem.bl32_ep_info;
+	SET_PARAM_HEAD(bl2_to_bl31_params->bl32_ep_info, PARAM_EP,
+		VERSION_1, 0);
+	bl2_to_bl31_params->bl32_image_info = &bl31_params_mem.bl32_image_info;
+	SET_PARAM_HEAD(bl2_to_bl31_params->bl32_image_info, PARAM_IMAGE_BINARY,
+		VERSION_1, 0);
+#endif
 
-	/* Fill BL33 related information */
-	bl2_to_bl31_params->bl33_ep_info = &bl31_params_mem->bl33_ep_info;
+	/* Fill BL3-3 related information */
+	bl2_to_bl31_params->bl33_ep_info = &bl31_params_mem.bl33_ep_info;
 	SET_PARAM_HEAD(bl2_to_bl31_params->bl33_ep_info,
 		PARAM_EP, VERSION_1, 0);
 	/* UEFI expects to receive the primary CPU MPID (through x0) */
 	bl2_to_bl31_params->bl33_ep_info->args.arg0 = PRIMARY_CPU;
 
-	bl2_to_bl31_params->bl33_image_info = &bl31_params_mem->bl33_image_info;
+	bl2_to_bl31_params->bl33_image_info = &bl31_params_mem.bl33_image_info;
 	SET_PARAM_HEAD(bl2_to_bl31_params->bl33_image_info, PARAM_IMAGE_BINARY,
 		VERSION_1, 0);
 
@@ -150,7 +143,7 @@ bl31_params_t *bl2_plat_get_bl31_params(void)
  ******************************************************************************/
 struct entry_point_info *bl2_plat_get_bl31_ep_info(void)
 {
-	return bl31_ep_info;
+	return &bl31_params_mem.bl31_ep_info;
 }
 
 /*******************************************************************************
@@ -253,7 +246,7 @@ void bl2_platform_setup(void)
 /* Flush the TF params and the TF plat params */
 void bl2_plat_flush_bl31_params(void)
 {
-	flush_dcache_range((unsigned long)PARAMS_BASE,
+	flush_dcache_range((unsigned long)&bl31_params_mem,
 			sizeof(bl2_to_bl31_params_mem_t));
 }
 

plat/juno/bl31_plat_setup.c

@@ -68,10 +68,11 @@ extern unsigned long __COHERENT_RAM_END__;
 #define BL31_COHERENT_RAM_LIMIT (unsigned long)(&__COHERENT_RAM_END__)
 
 /******************************************************************************
- * Reference to structures which hold the arguments that have been passed to
- * BL31 from BL2.
+ * Placeholder variables for copying the arguments that have been passed to
+ * BL3-1 from BL2.
  ******************************************************************************/
-static bl31_params_t *bl2_to_bl31_params;
+static entry_point_info_t bl32_ep_info;
+static entry_point_info_t bl33_ep_info;
 
 /*******************************************************************************
  * Return a pointer to the 'entry_point_info' structure of the next image for
@@ -83,9 +84,7 @@ entry_point_info_t *bl31_get_next_image_info(uint32_t type)
 {
 	entry_point_info_t *next_image_info;
 
-	next_image_info = (type == NON_SECURE) ?
-		bl2_to_bl31_params->bl33_ep_info :
-		bl2_to_bl31_params->bl32_ep_info;
+	next_image_info = (type == NON_SECURE) ? &bl33_ep_info : &bl32_ep_info;
 
 	/* None of the images on this platform can have 0x0 as the entrypoint */
 	if (next_image_info->pc)
@@ -98,10 +97,9 @@ entry_point_info_t *bl31_get_next_image_info(uint32_t type)
  * Perform any BL3-1 specific platform actions. Here is an opportunity to copy
  * parameters passed by the calling EL (S-EL1 in BL2 & S-EL3 in BL1) before they
  * are lost (potentially). This needs to be done before the MMU is initialized
- * so that the memory layout can be used while creating page tables. The 'data'
- * parameter is not used since all the information is contained in 'from_bl2'.
- * Also, BL2 has flushed this information to memory, so we are guaranteed to
- * pick up good data
+ * so that the memory layout can be used while creating page tables. Also, BL2
+ * has flushed this information to memory, so we are guaranteed to pick up good
+ * data
  ******************************************************************************/
 void bl31_early_platform_setup(bl31_params_t *from_bl2,
 			       void *plat_params_from_bl2)
@@ -112,8 +110,12 @@ void bl31_early_platform_setup(bl31_params_t *from_bl2,
 	assert(from_bl2->h.type == PARAM_BL31);
 	assert(from_bl2->h.version >= VERSION_1);
 
-	bl2_to_bl31_params = from_bl2;
-
+	/*
+	 * Copy BL3-2 and BL3-3 entry point information.
+	 * They are stored in Secure RAM, in BL2's address space.
+	 */
+	bl32_ep_info = *from_bl2->bl32_ep_info;
+	bl33_ep_info = *from_bl2->bl33_ep_info;
 }
 
 /*******************************************************************************

plat/juno/platform.h

@@ -134,10 +134,6 @@
 #define DRAM_BASE		0x80000000
 #define DRAM_SIZE		0x80000000
 
-/* Base address where parameters to BL31 are stored */
-/* Juno TODO: Move BL3-1 arguments somewhere in trusted memory  */
-#define PARAMS_BASE		DRAM_BASE
-
 /* Memory mapped Generic timer interfaces  */
 #define SYS_CNTCTL_BASE		0x2a430000