Add platform hooks for boot redundancy support
These hooks are intended to allow one platform to try load
images from alternative places. There is a hook to initialize
the sequence of boot locations and a hook to pass to the next
sequence.
Change-Id: Ia0f84c415208dc4fa4f9d060d58476db23efa5b2
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>
diff --git a/bl2/bl2_main.c b/bl2/bl2_main.c
index 0fe82d9..018deb3 100644
--- a/bl2/bl2_main.c
+++ b/bl2/bl2_main.c
@@ -34,6 +34,9 @@
auth_mod_init();
#endif /* TRUSTED_BOARD_BOOT */
+ /* initialize boot source */
+ bl2_plat_preload_setup();
+
/* Load the subsequent bootloader images. */
next_bl_ep_info = bl2_load_images();
diff --git a/common/bl_common.c b/common/bl_common.c
index cad4de9..e4473ed 100644
--- a/common/bl_common.c
+++ b/common/bl_common.c
@@ -354,7 +354,13 @@
******************************************************************************/
int load_auth_image(unsigned int image_id, image_info_t *image_data)
{
- return load_auth_image_internal(image_id, image_data, 0);
+ int err;
+
+ do {
+ err = load_auth_image_internal(image_id, image_data, 0);
+ } while (err != 0 && plat_try_next_boot_source());
+
+ return err;
}
#else /* LOAD_IMAGE_V2 */
@@ -553,8 +559,14 @@
image_info_t *image_data,
entry_point_info_t *entry_point_info)
{
- return load_auth_image_internal(mem_layout, image_id, image_base,
- image_data, entry_point_info, 0);
+ int err;
+
+ do {
+ err = load_auth_image_internal(mem_layout, image_id, image_base,
+ image_data, entry_point_info, 0);
+ } while (err != 0 && plat_try_next_boot_source());
+
+ return err;
}
#endif /* LOAD_IMAGE_V2 */
diff --git a/docs/porting-guide.rst b/docs/porting-guide.rst
index 6352bb9..f0a8aaf 100644
--- a/docs/porting-guide.rst
+++ b/docs/porting-guide.rst
@@ -1596,6 +1596,34 @@
This function isn't needed if either ``PRELOADED_BL33_BASE`` or ``EL3_PAYLOAD_BASE``
build options are used.
+Function : bl2\_plat\_preload\_setup [optional]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+ Argument : void
+ Return : void
+
+This optional function performs any BL2 platform initialization
+required before image loading, that is not done later in
+bl2\_platform\_setup(). Specifically, if support for multiple
+boot sources is required, it initializes the boot sequence used by
+plat\_try\_next\_boot\_source().
+
+Function : plat\_try\_next\_boot\_source() [optional]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+ Argument : void
+ Return : int
+
+This optional function passes to the next boot source in the redundancy
+sequence.
+
+This function moves the current boot redundancy source to the next
+element in the boot sequence. If there are no more boot sources then it
+must return 0, otherwise it must return 1. The default implementation
+of this always returns 0.
+
FWU Boot Loader Stage 2 (BL2U)
------------------------------
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index f03a399..e2bfa50 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -100,6 +100,8 @@
void plat_error_handler(int err) __dead2;
void plat_panic_handler(void) __dead2;
const char *plat_log_get_prefix(unsigned int log_level);
+void bl2_plat_preload_setup(void);
+int plat_try_next_boot_source(void);
/*******************************************************************************
* Mandatory BL1 functions
diff --git a/plat/common/aarch32/platform_helpers.S b/plat/common/aarch32/platform_helpers.S
index b5f41ff..61d21ab 100644
--- a/plat/common/aarch32/platform_helpers.S
+++ b/plat/common/aarch32/platform_helpers.S
@@ -14,6 +14,8 @@
.weak plat_disable_acp
.weak platform_mem_init
.weak plat_panic_handler
+ .weak bl2_plat_preload_setup
+ .weak plat_try_next_boot_source
/* -----------------------------------------------------
* Placeholder function which should be redefined by
@@ -79,3 +81,23 @@
func plat_panic_handler
b plat_panic_handler
endfunc plat_panic_handler
+
+
+ /* -----------------------------------------------------
+ * Placeholder function which should be redefined by
+ * each platfrom.
+ * -----------------------------------------------------
+ */
+func bl2_plat_preload_setup
+ bx lr
+endfunc bl2_plat_preload_setup
+
+ /* -----------------------------------------------------
+ * Placeholder function which should be redefined by
+ * each platfrom.
+ * -----------------------------------------------------
+ */
+func plat_try_next_boot_source
+ mov r0, #0
+ bx lr
+endfunc plat_try_next_boot_source
diff --git a/plat/common/aarch64/platform_helpers.S b/plat/common/aarch64/platform_helpers.S
index e60db20..797a936 100644
--- a/plat/common/aarch64/platform_helpers.S
+++ b/plat/common/aarch64/platform_helpers.S
@@ -17,6 +17,8 @@
.weak bl1_plat_prepare_exit
.weak plat_error_handler
.weak plat_panic_handler
+ .weak bl2_plat_preload_setup
+ .weak plat_try_next_boot_source
#if !ENABLE_PLAT_COMPAT
.globl platform_get_core_pos
@@ -129,3 +131,22 @@
wfi
b plat_panic_handler
endfunc plat_panic_handler
+
+ /* -----------------------------------------------------
+ * Placeholder function which should be redefined by
+ * each platfrom.
+ * -----------------------------------------------------
+ */
+func bl2_plat_preload_setup
+ ret
+endfunc bl2_plat_preload_setup
+
+ /* -----------------------------------------------------
+ * Placeholder function which should be redefined by
+ * each platfrom.
+ * -----------------------------------------------------
+ */
+func plat_try_next_boot_source
+ mov x0, #0
+ ret
+endfunc plat_try_next_boot_source