[PATCH] make the code simpler
u74147 at gmail.com
u74147 at gmail.com
Mon Dec 2 12:17:46 EST 2013
From: Du Huanpeng <u74147 at gmail.com>
Signed-off-by: Du Huanpeng <u74147 at gmail.com>
---
arch/mips/boot/start.S | 26 +++-----------------------
1 file changed, 3 insertions(+), 23 deletions(-)
diff --git a/arch/mips/boot/start.S b/arch/mips/boot/start.S
index 7e2ae5e..474407d 100644
--- a/arch/mips/boot/start.S
+++ b/arch/mips/boot/start.S
@@ -25,26 +25,6 @@
#include <generated/compile.h>
#include <generated/utsrelease.h>
- /*
- * ADR macro instruction (inspired by ARM)
- *
- * ARM architecture doesn't have PC-relative jump instruction
- * like MIPS' B/BAL insns. When ARM makes PC-relative jumps,
- * it uses ADR insn. ADR is used to get a destination address
- * of 'label' against current PC. With this, ARM can safely
- * make PC-relative jumps.
- */
- .macro ADR rd label temp
- .set push
- .set noreorder
- move \temp, ra # preserve ra beforehand
- bal _pc
- nop
-_pc: addiu \rd, ra, \label - _pc # label is assumed to be
- move ra, \temp # within pc +/- 32KB
- .set pop
- .endm
-
.set noreorder
.text
.section ".text_bare_init"
@@ -52,8 +32,9 @@ _pc: addiu \rd, ra, \label - _pc # label is assumed to be
EXPORT(_start)
- b __start
+ bal __start
nop
+_ra:
.org 0x10
.ascii "barebox " UTS_RELEASE " " UTS_VERSION
@@ -72,8 +53,7 @@ __start:
mtc0 k0, CP0_STATUS
/* copy barebox to link location */
- ADR a0, _start, t1 /* a0 <- pc-relative position of _start */
-
+ addiu a0, ra, (_start - _ra) /*a0 <- pc-relative position of _start */
la a1, _start /* link (RAM) _start address */
beq a0, a1, stack_setup
--
1.7.9.5
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