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[PATCH][AArch64][libgloss] Tidy up WXN bit clearing
- From: Kyrill Tkachov <kyrylo dot tkachov at arm dot com>
- To: newlib at sourceware dot org
- Cc: Marcus Shawcroft <Marcus dot Shawcroft at arm dot com>
- Date: Tue, 28 Jan 2014 09:06:13 +0000
- Subject: [PATCH][AArch64][libgloss] Tidy up WXN bit clearing
- Authentication-results: sourceware.org; auth=none
Hi all,
The patch I sent out recently to clear the WXN bit could be improved a bit.
We can use the assembler bic-immediate pseudo-instruction instead of a
mov-immediate and register-bic.
This patch shortens that sequence a bit.
Sorry for the noise.
Ok?
Tested aarch64-none-elf on a model.
P.S. Can someone please install this if ok'd?
[libgloss/]
2014-01-28 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
* aarch64/cpu-init/rdimon-aem-el3.S (flat_map): Use bic-immediate
form to clear WXN bit.diff --git a/libgloss/aarch64/cpu-init/rdimon-aem-el3.S b/libgloss/aarch64/cpu-init/rdimon-aem-el3.S
index 4637627..41db8f9 100644
--- a/libgloss/aarch64/cpu-init/rdimon-aem-el3.S
+++ b/libgloss/aarch64/cpu-init/rdimon-aem-el3.S
@@ -139,8 +139,7 @@ _flat_map:
mrs x0, sctlr_el3
ldr x1, =0x100d /* bits I(12) SA(3) C(2) M(0) */
bic x0, x0, #(1 << 1) /* clear bit A(1) */
- mov x2, #(1 << 19) /* clear WXN */
- bic x0, x0, x2
+ bic x0, x0, #(1 << 19) /* clear WXN */
orr x0, x0, x1 /* set bits */
dsb sy