u-boot/arch/arm/cpu/armv7/sunxi/fel_utils.S
Andre Przywara 7f0938eac5 sunxi: fel: drop redundant "control register" save/restore
For some reasons shrouded in mystery, the code saving the FEL state was
saving the SCTLR register twice, with the second copy trying to justify
itself by using its ancient "control register" alias name.

Drop the redundant second copy, both from the fel_stash data structure,
and also the code saving and restoring it.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>
Tested-by: Samuel Holland <samuel@sholland.org>
2023-01-21 01:32:23 +00:00

37 lines
800 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Utility functions for FEL mode.
*
* Copyright (c) 2015 Google, Inc
*/
#include <asm-offsets.h>
#include <config.h>
#include <asm/system.h>
#include <linux/linkage.h>
ENTRY(save_boot_params)
ldr r0, =fel_stash
str sp, [r0, #0]
str lr, [r0, #4]
mrs lr, cpsr @ Read CPSR
str lr, [r0, #8]
mrc p15, 0, lr, c1, c0, 0 @ Read CP15 SCTLR Register
str lr, [r0, #12]
mrc p15, 0, lr, c12, c0, 0 @ Read VBAR
str lr, [r0, #16]
b save_boot_params_ret
ENDPROC(save_boot_params)
ENTRY(return_to_fel)
mov sp, r0
mov lr, r1
ldr r0, =fel_stash
ldr r1, [r0, #16]
mcr p15, 0, r1, c12, c0, 0 @ Write VBAR
ldr r1, [r0, #12]
mcr p15, 0, r1, c1, c0, 0 @ Write CP15 SCTLR Register
ldr r1, [r0, #8]
msr cpsr, r1 @ Write CPSR
bx lr
ENDPROC(return_to_fel)