Patchwork [U-Boot] MIPS: simplify relocated _G_O_T_ address calculation

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Submitter Gabor Juhos
Date Jan. 22, 2013, 7:05 a.m.
Message ID <1358838305-17209-1-git-send-email-juhosg@openwrt.org>
Download mbox | patch
Permalink /patch/214350/
State Superseded
Delegated to: Daniel Schwierzeck
Headers show

Comments

Gabor Juhos - Jan. 22, 2013, 7:05 a.m.
The difference between the address of the original
and the relocated _GLOBAL_OFFSET_TABLE_ is always
the same as the relocation offset.

The relocation offset is already computed and it is
available in the 's1' register. Use that to adjust
the relocated _G_O_T_ address, instead of calculating
the offset again from the _gp value.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>
---
 arch/mips/cpu/mips32/start.S |    5 +----
 arch/mips/cpu/mips64/start.S |    5 +----
 2 files changed, 2 insertions(+), 8 deletions(-)

Patch

diff --git a/arch/mips/cpu/mips32/start.S b/arch/mips/cpu/mips32/start.S
index 9c1b2f7..9d6d671 100644
--- a/arch/mips/cpu/mips32/start.S
+++ b/arch/mips/cpu/mips32/start.S
@@ -328,7 +328,6 @@  relocate_code:
 	jr	t0
 	 nop
 
-	.word	_gp
 	.word	_GLOBAL_OFFSET_TABLE_
 	.word	uboot_end_data
 	.word	uboot_end
@@ -343,9 +342,7 @@  in_ram:
 	 */
 	lw	t3, -4(t0)		# t3 <-- num_got_entries
 	lw	t4, -16(t0)		# t4 <-- _GLOBAL_OFFSET_TABLE_
-	lw	t5, -20(t0)		# t5 <-- _gp
-	sub	t4, t5			# compute offset
-	add	t4, t4, gp		# t4 now holds relocated _G_O_T_
+	add	t4, s1			# t4 now holds relocated _G_O_T_
 	addi	t4, t4, 8		# skipping first two entries
 	li	t2, 2
 1:
diff --git a/arch/mips/cpu/mips64/start.S b/arch/mips/cpu/mips64/start.S
index 2b8d531..ae3b00b 100644
--- a/arch/mips/cpu/mips64/start.S
+++ b/arch/mips/cpu/mips64/start.S
@@ -207,7 +207,6 @@  relocate_code:
 	jr	t0
 	 nop
 
-	.dword	_gp
 	.dword	_GLOBAL_OFFSET_TABLE_
 	.dword	uboot_end_data
 	.dword	uboot_end
@@ -222,9 +221,7 @@  in_ram:
 	 */
 	ld	t3, -8(t0)		# t3 <-- num_got_entries
 	ld	t8, -32(t0)		# t8 <-- _GLOBAL_OFFSET_TABLE_
-	ld	t9, -40(t0)		# t9 <-- _gp
-	dsub	t8, t9			# compute offset
-	dadd	t8, t8, gp		# t8 now holds relocated _G_O_T_
+	dadd	t8, s1			# t8 now holds relocated _G_O_T_
 	daddi	t8, t8, 16		# skipping first two entries
 	dli	t2, 2
 1: