[PATCH v10 1/3] ARM: uncompress: Add be32tocpu macro

From: Geert Uytterhoeven
Date: Thu Dec 03 2020 - 07:20:18 EST


DTB stores all values as 32-bit big-endian integers.
Add a macro to convert such values to native CPU endianness, to reduce
duplication.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
v10:
- New.
---
arch/arm/boot/compressed/head.S | 26 ++++++++++++--------------
1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 835ce64f1674c9a2..aabdc544c03aafdc 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -165,6 +165,16 @@
orr \res, \res, \tmp1, lsl #24
.endm

+ .macro be32tocpu, val, tmp
+#ifndef __ARMEB__
+ /* convert to little endian */
+ eor \tmp, \val, \val, ror #16
+ bic \tmp, \tmp, #0x00ff0000
+ mov \val, \val, ror #8
+ eor \val, \val, \tmp, lsr #8
+#endif
+ .endm
+
.section ".start", "ax"
/*
* sort out different calling conventions
@@ -345,13 +355,7 @@ restart: adr r0, LC1

/* Get the initial DTB size */
ldr r5, [r6, #4]
-#ifndef __ARMEB__
- /* convert to little endian */
- eor r1, r5, r5, ror #16
- bic r1, r1, #0x00ff0000
- mov r5, r5, ror #8
- eor r5, r5, r1, lsr #8
-#endif
+ be32tocpu r5, r1
dbgadtb r6, r5
/* 50% DTB growth should be good enough */
add r5, r5, r5, lsr #1
@@ -403,13 +407,7 @@ restart: adr r0, LC1

/* Get the current DTB size */
ldr r5, [r6, #4]
-#ifndef __ARMEB__
- /* convert r5 (dtb size) to little endian */
- eor r1, r5, r5, ror #16
- bic r1, r1, #0x00ff0000
- mov r5, r5, ror #8
- eor r5, r5, r1, lsr #8
-#endif
+ be32tocpu r5, r1

/* preserve 64-bit alignment */
add r5, r5, #7
--
2.25.1