u-boot/arch/arm/cpu/armv7/sctlr.S
Heinrich Schuchardt 78f90aaeec arm: armv7: allow unaligned memory access
The UEFI spec mandates that unaligned memory access should be enabled if
supported by the CPU architecture.

This patch implements the function unaligned_access() to reset the aligned
access flag in the system control register (SCTLR). It is called when the
bootefi command is invoked.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
[agraf: fix SPDX identifier]
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-06-03 15:27:21 +02:00

22 lines
648 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Routines to access the system control register
*
* Copyright (c) 2018 Heinrich Schuchardt
*/
#include <linux/linkage.h>
/*
* void allow_unaligned(void) - allow unaligned access
*
* This routine clears the aligned flag in the system control register.
* After calling this routine unaligned access does no longer lead to a
* data abort but is handled by the CPU.
*/
ENTRY(allow_unaligned)
mrc p15, 0, r0, c1, c0, 0 @ load system control register
bic r0, r0, #2 @ clear aligned flag
mcr p15, 0, r0, c1, c0, 0 @ write system control register
bx lr @ return
ENDPROC(allow_unaligned)