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authorGabor Juhos <juhosg@openwrt.org>2013-01-30 04:51:06 +0000
committerDaniel Schwierzeck <daniel.schwierzeck@gmail.com>2013-01-30 23:33:27 +0100
commit6d8622788020265a9e98e8345c6435c8680c992c (patch)
tree7abf0101a930ce97f5b9126c43735348e5967a1d /arch/mips/cpu/xburst
parent025f2b338072781cd747bf7365cf43fcf9f40f1a (diff)
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MIPS: xburst: simplify relocation offset calculation
The current code uses four instructions and a temporary register to calculate the relocation offset and to adjust the gp register. The relocation offset can be calculated directly from the CONFIG_SYS_MONITOR_BASE constant and from the destination address. The resulting offset can be used to adjust the gp pointer. This approach makes the code a bit simpler because it needs two instructions only. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Cc: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com> Cc: Xiangfu Liu <xiangfu@openmobilefree.net>
Diffstat (limited to 'arch/mips/cpu/xburst')
-rw-r--r--arch/mips/cpu/xburst/start.S12
1 files changed, 3 insertions, 9 deletions
diff --git a/arch/mips/cpu/xburst/start.S b/arch/mips/cpu/xburst/start.S
index 9e637df..50b7fb1 100644
--- a/arch/mips/cpu/xburst/start.S
+++ b/arch/mips/cpu/xburst/start.S
@@ -64,19 +64,13 @@ relocate_code:
move sp, a0 # set new stack pointer
li t0, CONFIG_SYS_MONITOR_BASE
+ sub t6, a2, t0 # t6 <-- relocation offset
+
la t3, in_ram
lw t2, -12(t3) # t2 <-- uboot_end_data
move t1, a2
- /*
- * Fix $gp:
- *
- * New $gp = (Old $gp - CONFIG_SYS_MONITOR_BASE) + Destination Address
- */
- move t6, gp
- sub gp, CONFIG_SYS_MONITOR_BASE
- add gp, a2 # gp now adjusted
- sub t6, gp, t6 # t6 <-- relocation offset
+ add gp, t6 # adjust gp
/*
* t0 = source address