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

Jiaxun Yang
2020-12-21T13:03:06Z

.cprestore is removed as we don't except Position Independent
zboot ELF.

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

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

Reported-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
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:
/* 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
--
2.29.2