AcoSail/kernel_optimize_test
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ARC: optimize kernel bss clearing in early boot code

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using ARC ZOL which reduces tot num of instructions by half

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2014-04-17 17:13:26 +05:30
parent ba25915fb2
commit bef444a330
2 changed files with 5 additions and 4 deletions
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7
arch/arc/kernel/head.S
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@ -77,10 +77,11 @@ stext:
; Clear BSS before updating any globals
; XXX: use ZOL here
mov r5, __bss_start
mov r6, __bss_stop
sub r6, __bss_stop, r5
lsr.f lp_count, r6, 2
lpnz 1f
st.ab 0, [r5, 4]
1:
st.ab 0, [r5,4]
brlt r5, r6, 1b
; Uboot - kernel ABI
; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2

2
arch/arc/kernel/vmlinux.lds.S
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@ -116,7 +116,7 @@ SECTIONS
_edata = .;
BSS_SECTION(0, 0, 0)
BSS_SECTION(4, 4, 4)
#ifdef CONFIG_ARC_DW2_UNWIND
. = ALIGN(PAGE_SIZE);