[U-Boot] [PATCH v3] board_r - fixup functions table after relocation

Alexey Brodkin abrodkin at synopsys.com
Mon Jan 20 11:30:39 CET 2014


This is only required for "PIC" relocation and doesn't apply to modern
"PIE" relocation which does data relocation as well as code.

"init_sequence_r" is just an array that consists of compile-time
adresses of init functions. Since this is basically an array of integers
(pointers to "void" to be more precise) it won't be modified during
relocation - it will be just copied to new location as it is.

As a consequence on execution after relocation "initcall_run_list" will
be jumping to pre-relocation addresses. As long as we don't overwrite
pre-relocation memory area init calls are executed correctly. But still
it is dangerous because after relocation we don't expect initially used
memory to stay untouched.

Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>

Cc: Tom Rini <trini at ti.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Masahiro Yamada <yamada.m at jp.panasonic.com>
Cc: Doug Anderson <dianders at chromium.org>
Cc: Thomas Langer <thomas.langer at lantiq.com>
Cc: Albert ARIBAUD <albert.u.boot at aribaud.net>

Changes to v2:
 * Use ARRAY_SIZE as suggested by Simon Glass
 * Added CONFIG_NEEDS_MANUAL_RELOC wrapper for temporary index variable
"i" to fix compile-time warning for boards without
CONFIG_NEEDS_MANUAL_RELOC
---
 common/board_r.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/common/board_r.c b/common/board_r.c
index 86ca1cb..c2d0763 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -903,9 +903,19 @@ init_fnc_t init_sequence_r[] = {
 
 void board_init_r(gd_t *new_gd, ulong dest_addr)
 {
+#ifdef CONFIG_NEEDS_MANUAL_RELOC
+	int i;
+#endif
+
 #ifndef CONFIG_X86
 	gd = new_gd;
 #endif
+
+#ifdef CONFIG_NEEDS_MANUAL_RELOC
+	for (i = 0; i < ARRAY_SIZE(init_sequence_r); i++)
+		init_sequence_r[i] += gd->reloc_off;
+#endif
+
 	if (initcall_run_list(init_sequence_r))
 		hang();
 
-- 
1.8.4.2



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