Panic if platform specific BL3-0 handling fails

The return value of bl2_plat_handle_bl30() used to be ignored.
This patch modifies the function load_bl30() so that it now
checks this return value and returns it to bl2_main().

This patch also unifies the error handling code across the
load_blx() functions so that they return a status code in all
cases and bl2_main() has the sole responsibility of panicking
if appropriate.

Change-Id: I2b26cdf65afa443b48c7da1fa7da8db956071bfb
diff --git a/bl2/bl2_main.c b/bl2/bl2_main.c
index 29ca0a5..fb79f04 100644
--- a/bl2/bl2_main.c
+++ b/bl2/bl2_main.c
@@ -205,23 +205,28 @@
 		       &bl30_image_info,
 		       NULL);
 
-	if (e == 0) {
+	if (e)
+		return e;
+
 #if TRUSTED_BOARD_BOOT
-		e = auth_verify_obj(AUTH_BL30_IMG,
-				bl30_image_info.image_base,
-				bl30_image_info.image_size);
-		if (e) {
-			ERROR("Failed to authenticate BL3-0 image.\n");
-			panic();
-		}
+	e = auth_verify_obj(AUTH_BL30_IMG,
+			bl30_image_info.image_base,
+			bl30_image_info.image_size);
+	if (e) {
+		ERROR("Failed to authenticate BL3-0 image.\n");
+		return e;
+	}
 
-		/* After working with data, invalidate the data cache */
-		inv_dcache_range(bl30_image_info.image_base,
-				 (size_t)bl30_image_info.image_size);
+	/* After working with data, invalidate the data cache */
+	inv_dcache_range(bl30_image_info.image_base,
+			(size_t)bl30_image_info.image_size);
 #endif /* TRUSTED_BOARD_BOOT */
 
-		/* The subsequent handling of BL3-0 is platform specific */
-		bl2_plat_handle_bl30(&bl30_image_info);
+	/* The subsequent handling of BL3-0 is platform specific */
+	e = bl2_plat_handle_bl30(&bl30_image_info);
+	if (e) {
+		ERROR("Failure in platform-specific handling of BL3-0 image.\n");
+		return e;
 	}
 #endif /* BL30_BASE */
 
@@ -256,25 +261,25 @@
 		       BL31_BASE,
 		       bl2_to_bl31_params->bl31_image_info,
 		       bl31_ep_info);
+	if (e)
+		return e;
 
-	if (e == 0) {
 #if TRUSTED_BOARD_BOOT
-		e = auth_verify_obj(AUTH_BL31_IMG,
-			bl2_to_bl31_params->bl31_image_info->image_base,
-			bl2_to_bl31_params->bl31_image_info->image_size);
-		if (e) {
-			ERROR("Failed to authenticate BL3-1 image.\n");
-			panic();
-		}
+	e = auth_verify_obj(AUTH_BL31_IMG,
+			    bl2_to_bl31_params->bl31_image_info->image_base,
+			    bl2_to_bl31_params->bl31_image_info->image_size);
+	if (e) {
+		ERROR("Failed to authenticate BL3-1 image.\n");
+		return e;
+	}
 
-		/* After working with data, invalidate the data cache */
-		inv_dcache_range(bl2_to_bl31_params->bl31_image_info->image_base,
+	/* After working with data, invalidate the data cache */
+	inv_dcache_range(bl2_to_bl31_params->bl31_image_info->image_base,
 			(size_t)bl2_to_bl31_params->bl31_image_info->image_size);
 #endif /* TRUSTED_BOARD_BOOT */
 
-		bl2_plat_set_bl31_ep_info(bl2_to_bl31_params->bl31_image_info,
-					  bl31_ep_info);
-	}
+	bl2_plat_set_bl31_ep_info(bl2_to_bl31_params->bl31_image_info,
+				  bl31_ep_info);
 
 	return e;
 }
@@ -309,30 +314,31 @@
 		       bl2_to_bl31_params->bl32_image_info,
 		       bl2_to_bl31_params->bl32_ep_info);
 
-	if (e == 0) {
+	if (e)
+		return e;
+
 #if TRUSTED_BOARD_BOOT
-		/* Image is present. Check if there is a valid certificate */
-		if (bl32_cert_error) {
-			ERROR("Failed to authenticate BL3-2 certificates.\n");
-			panic();
-		}
+	/* Image is present. Check if there is a valid certificate */
+	if (bl32_cert_error) {
+		ERROR("Failed to authenticate BL3-2 certificates.\n");
+		return bl32_cert_error;
+	}
 
-		e = auth_verify_obj(AUTH_BL32_IMG,
-			bl2_to_bl31_params->bl32_image_info->image_base,
-			bl2_to_bl31_params->bl32_image_info->image_size);
-		if (e) {
-			ERROR("Failed to authenticate BL3-2 image.\n");
-			panic();
-		}
-		/* After working with data, invalidate the data cache */
-		inv_dcache_range(bl2_to_bl31_params->bl32_image_info->image_base,
+	e = auth_verify_obj(AUTH_BL32_IMG,
+			    bl2_to_bl31_params->bl32_image_info->image_base,
+			    bl2_to_bl31_params->bl32_image_info->image_size);
+	if (e) {
+		ERROR("Failed to authenticate BL3-2 image.\n");
+		return e;
+	}
+	/* After working with data, invalidate the data cache */
+	inv_dcache_range(bl2_to_bl31_params->bl32_image_info->image_base,
 			(size_t)bl2_to_bl31_params->bl32_image_info->image_size);
 #endif /* TRUSTED_BOARD_BOOT */
 
-		bl2_plat_set_bl32_ep_info(
-			bl2_to_bl31_params->bl32_image_info,
-			bl2_to_bl31_params->bl32_ep_info);
-	}
+	bl2_plat_set_bl32_ep_info(
+		bl2_to_bl31_params->bl32_image_info,
+		bl2_to_bl31_params->bl32_ep_info);
 #endif /* BL32_BASE */
 
 	return e;
@@ -361,23 +367,24 @@
 		       bl2_to_bl31_params->bl33_image_info,
 		       bl2_to_bl31_params->bl33_ep_info);
 
-	if (e == 0) {
+	if (e)
+		return e;
+
 #if TRUSTED_BOARD_BOOT
-		e = auth_verify_obj(AUTH_BL33_IMG,
-				bl2_to_bl31_params->bl33_image_info->image_base,
-				bl2_to_bl31_params->bl33_image_info->image_size);
-		if (e) {
-			ERROR("Failed to authenticate BL3-3 image.\n");
-			panic();
-		}
-		/* After working with data, invalidate the data cache */
-		inv_dcache_range(bl2_to_bl31_params->bl33_image_info->image_base,
+	e = auth_verify_obj(AUTH_BL33_IMG,
+			    bl2_to_bl31_params->bl33_image_info->image_base,
+			    bl2_to_bl31_params->bl33_image_info->image_size);
+	if (e) {
+		ERROR("Failed to authenticate BL3-3 image.\n");
+		return e;
+	}
+	/* After working with data, invalidate the data cache */
+	inv_dcache_range(bl2_to_bl31_params->bl33_image_info->image_base,
 			(size_t)bl2_to_bl31_params->bl33_image_info->image_size);
 #endif /* TRUSTED_BOARD_BOOT */
 
-		bl2_plat_set_bl33_ep_info(bl2_to_bl31_params->bl33_image_info,
-					  bl2_to_bl31_params->bl33_ep_info);
-	}
+	bl2_plat_set_bl33_ep_info(bl2_to_bl31_params->bl33_image_info,
+				  bl2_to_bl31_params->bl33_ep_info);
 
 	return e;
 }