9os

commit 2325fcee1b723ddb76de59e811eddd4b84683cfb
parent 7295f73733261237a25a956e23aea16bc98e024e
Author: Dimitris Papastamos <dimitris.papastamos@arm.com>
Date:   Wed, 17 Oct 2018 11:06:40 +0100

[arm64/crt] Scrub SRAM

One of the requirements of the SysArch specification is to scrub SRAM
before using it.

Change-Id: I0dfe4fd1fcc1090fc56fc77207926acccfad06b1
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Diffstat:
M
arch/arm64/crt-none.s
 | 
15
+++++++++++++++

1 file changed, 15 insertions(+), 0 deletions(-)
diff --git a/arch/arm64/crt-none.s b/arch/arm64/crt-none.s
@@ -9,6 +9,10 @@ _start:
 getpc:
 	sub	x30,x30,4
 
+	ldr	x0,=SRAMADDR
+	mov	x1,#SRAMSIZE
+	bl	initmem
+
 	adr	x0,vectbl
 	msr	S3_6_C12_C0_6,x0	/* VBAR_R */
 	isb
@@ -28,6 +32,17 @@ getpc:
 	adr	x0,outsync
 	b	panic
 
+/* Scrub SRAM */
+initmem:
+	stp	xzr,xzr,[x0],#16
+	stp	xzr,xzr,[x0],#16
+	stp	xzr,xzr,[x0],#16
+	stp	xzr,xzr,[x0],#16
+	sub	x1,x1,#64
+	cmp	x1,#0
+	b.ne	initmem
+	ret
+
 	.section	.rodata
 outsync:
 	.asciz	"out of sync"