bootstate: use structure pointers for scheduling callbacks

The GCC 4.9.2 update showed that the boot_state_init_entry
structures were being padded and assumed to be aligned in to an
increased size. The bootstate scheduler for static entries,
boot_state_schedule_static_entries(), was then calculating the
wrong values within the array. To fix this just use a pointer to
the boot_state_init_entry structure that needs to be scheduled.

In addition to the previous issue noted above, the .bs_init
section was sitting in the read only portion of the image while
the fields within it need to be writable. Also, the
boot_state_schedule_static_entries() was using symbol comparison
to terminate a loop which in C can lead the compiler to always
evaluate the loop at least once since the language spec indicates
no 2 symbols can be the same value.

Change-Id: I6dc5331c2979d508dde3cd5c3332903d40d8048b
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/8699
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

4 files changed, 12 insertions, 20 deletions

diff --git a/src/lib/dynamic_cbmem.c b/src/lib/dynamic_cbmem.c
index daa37172c4..3b008c7614 100644
--- a/src/lib/dynamic_cbmem.c
+++ b/src/lib/dynamic_cbmem.c
@@ -435,11 +435,7 @@ static void init_cbmem_pre_device(void *unused)
 	cbmem_initialize();
 }
 
-BOOT_STATE_INIT_ENTRIES(cbmem_bscb) = {
-	BOOT_STATE_INIT_ENTRY(BS_PRE_DEVICE, BS_ON_ENTRY,
-	                      init_cbmem_pre_device, NULL),
-};
-
+BOOT_STATE_INIT_ENTRY(BS_PRE_DEVICE, BS_ON_ENTRY, init_cbmem_pre_device, NULL);
 #else
 
 static void init_cbmem_post_device(void *unused)
@@ -450,10 +446,8 @@ static void init_cbmem_post_device(void *unused)
 		cbmem_initialize_empty();
 }
 
-BOOT_STATE_INIT_ENTRIES(cbmem_bscb) = {
-	BOOT_STATE_INIT_ENTRY(BS_POST_DEVICE, BS_ON_ENTRY,
-	                      init_cbmem_post_device, NULL),
-};
+BOOT_STATE_INIT_ENTRY(BS_POST_DEVICE, BS_ON_ENTRY,
+			init_cbmem_post_device, NULL);
 #endif
 
 void cbmem_add_bootmem(void)
diff --git a/src/lib/gcov-glue.c b/src/lib/gcov-glue.c
index ab9062b497..615624fadb 100644
--- a/src/lib/gcov-glue.c
+++ b/src/lib/gcov-glue.c
@@ -150,8 +150,6 @@ static void coverage_exit(void *unused)
 	__gcov_flush();
 }
 
-BOOT_STATE_INIT_ENTRIES(gcov_bscb) = {
-	BOOT_STATE_INIT_ENTRY(BS_PRE_DEVICE, BS_ON_ENTRY, coverage_init, NULL),
-	BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, coverage_exit, NULL),
-	BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_LOAD, BS_ON_EXIT, coverage_exit, NULL),
-};
+BOOT_STATE_INIT_ENTRY(BS_PRE_DEVICE, BS_ON_ENTRY, coverage_init, NULL);
+BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, coverage_exit, NULL);
+BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_LOAD, BS_ON_EXIT, coverage_exit, NULL);
diff --git a/src/lib/hardwaremain.c b/src/lib/hardwaremain.c
index 32162eb954..d16aa09a29 100644
--- a/src/lib/hardwaremain.c
+++ b/src/lib/hardwaremain.c
@@ -432,18 +432,16 @@ int boot_state_sched_on_exit(struct boot_state_callback *bscb,
 
 static void boot_state_schedule_static_entries(void)
 {
-	extern struct boot_state_init_entry _bs_init_begin;
-	extern struct boot_state_init_entry _bs_init_end;
-	struct boot_state_init_entry *cur;
+	extern struct boot_state_init_entry *_bs_init_begin[];
+	struct boot_state_init_entry **slot;
 
-	cur = &_bs_init_begin;
+	for (slot = &_bs_init_begin[0]; *slot != NULL; slot++) {
+		struct boot_state_init_entry *cur = *slot;
 
-	while (cur != &_bs_init_end) {
 		if (cur->when == BS_ON_ENTRY)
 			boot_state_sched_on_entry(&cur->bscb, cur->state);
 		else
 			boot_state_sched_on_exit(&cur->bscb, cur->state);
-		cur++;
 	}
 }
 
diff --git a/src/lib/rmodule.ld b/src/lib/rmodule.ld
index c1669becb6..065b5b642e 100644
--- a/src/lib/rmodule.ld
+++ b/src/lib/rmodule.ld
@@ -49,6 +49,8 @@ SECTIONS
 		. = ALIGN(8);
 		_bs_init_begin = .;
 		KEEP(*(.bs_init));
+		LONG(0);
+		LONG(0);
 		_bs_init_end = .;
 
 		. = ALIGN(8);