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authorMichal Simek <monstr@monstr.eu>2011-01-31 08:57:26 -0500
committerMichal Simek <monstr@monstr.eu>2011-03-09 02:09:53 -0500
commit495162dfefe3f6e3a8e908aa2f0a964a572d3e87 (patch)
treead617d05d68d674bccf7820c1d2def4433e82693 /arch/microblaze/kernel
parent601149775158ea825326734c2db5d90190249bd7 (diff)
microblaze: Optimize BE/LE bootup detecting
Save 0x1 word to rodata section and remove online value loading if DTB is passed from bootloader. It saves two asm instructions in bootup. Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/kernel')
-rw-r--r--arch/microblaze/kernel/head.S12
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S
index 778a5ce2e4fc..d8dc085a9456 100644
--- a/arch/microblaze/kernel/head.S
+++ b/arch/microblaze/kernel/head.S
@@ -39,7 +39,7 @@
39#include <asm/mmu.h> 39#include <asm/mmu.h>
40#include <asm/processor.h> 40#include <asm/processor.h>
41 41
42.data 42.section .data
43.global empty_zero_page 43.global empty_zero_page
44.align 12 44.align 12
45empty_zero_page: 45empty_zero_page:
@@ -50,6 +50,11 @@ swapper_pg_dir:
50 50
51#endif /* CONFIG_MMU */ 51#endif /* CONFIG_MMU */
52 52
53.section .rodata
54.align 4
55endian_check:
56 .word 1
57
53 __HEAD 58 __HEAD
54ENTRY(_start) 59ENTRY(_start)
55#if CONFIG_KERNEL_BASE_ADDR == 0 60#if CONFIG_KERNEL_BASE_ADDR == 0
@@ -79,10 +84,7 @@ real_start:
79/* Does r7 point to a valid FDT? Load HEADER magic number */ 84/* Does r7 point to a valid FDT? Load HEADER magic number */
80 /* Run time Big/Little endian platform */ 85 /* Run time Big/Little endian platform */
81 /* Save 1 as word and load byte - 0 - BIG, 1 - LITTLE */ 86 /* Save 1 as word and load byte - 0 - BIG, 1 - LITTLE */
82 addik r11, r0, 0x1 /* BIG/LITTLE checking value */ 87 lbui r11, r0, TOPHYS(endian_check)
83 /* __bss_start will be zeroed later - it is just temp location */
84 swi r11, r0, TOPHYS(__bss_start)
85 lbui r11, r0, TOPHYS(__bss_start)
86 beqid r11, big_endian /* DO NOT break delay stop dependency */ 88 beqid r11, big_endian /* DO NOT break delay stop dependency */
87 lw r11, r0, r7 /* Big endian load in delay slot */ 89 lw r11, r0, r7 /* Big endian load in delay slot */
88 lwr r11, r0, r7 /* Little endian load */ 90 lwr r11, r0, r7 /* Little endian load */