Re: [PATCH v2] MIPS: zboot: head.S clean up

From: Jiaxun Yang
Date: Tue Dec 29 2020 - 22:46:50 EST


在 2020/12/30 上午11:08, Jiaxun Yang 写道:
.cprestore is removed as we don't expect Position Independent
zboot ELF.

.noreorder is also removed and rest instructions are massaged
to improve readability.

t9 register is used for indirect jump as MIPS ABI requirement.

start label is removed as it already defined in LEAF.

Reported-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>

--
v2: Remove start label (paul)
---
arch/mips/boot/compressed/head.S | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/mips/boot/compressed/head.S b/arch/mips/boot/compressed/head.S
index 409cb483a9ff..977218c90bc8 100644
--- a/arch/mips/boot/compressed/head.S
+++ b/arch/mips/boot/compressed/head.S
@@ -15,8 +15,6 @@
#include <asm/asm.h>
#include <asm/regdef.h>
- .set noreorder
- .cprestore
LEAF(start)
start:

Oops, it's still here, sorry for the noise.

Thanks

- Jiaxun

/* Save boot rom start args */
@@ -35,21 +33,20 @@ start:
PTR_LA a0, (.heap) /* heap address */
PTR_LA sp, (.stack + 8192) /* stack address */
- PTR_LA ra, 2f
- PTR_LA k0, decompress_kernel
- jr k0
- nop
+ PTR_LA t9, decompress_kernel
+ jalr t9
+
2:
move a0, s0
move a1, s1
move a2, s2
move a3, s3
- PTR_LI k0, KERNEL_ENTRY
- jr k0
- nop
+ PTR_LI t9, KERNEL_ENTRY
+ jalr t9
+
3:
b 3b
- nop
+
END(start)
.comm .heap,BOOT_HEAP_SIZE,4