From 56055e87b0a756d4756a22ed26b855fbe7afe93c Mon Sep 17 00:00:00 2001 From: Stephan Gerhold Date: Mon, 17 Apr 2023 14:47:40 +0200 Subject: fix(bl32): avoid clearing argument registers in RESET_TO_SP_MIN case RESET_TO_SP_MIN is also used by platforms with a non TF-A bootloader, in which case there might be platform-specific arguments passed in the CPU registers. At the moment these are cleared and cannot be used by the platform layer. For BL31 this was recently changed in "fix(bl31): avoid clearing of argument registers in RESET_TO_BL31 case", but on AArch32 SP_MIN still has the old behavior. Make this consistent by preserving the registers in SP_MIN as well and use the chance to clarify the existing comments a bit. Change-Id: I0039c72477249eed76c3da23cb4f10ac59b310d0 Signed-off-by: Stephan Gerhold --- bl32/sp_min/aarch32/entrypoint.S | 29 +++++++---------------------- 1 file changed, 7 insertions(+), 22 deletions(-) (limited to 'bl32') diff --git a/bl32/sp_min/aarch32/entrypoint.S b/bl32/sp_min/aarch32/entrypoint.S index f10296724..693dd4b82 100644 --- a/bl32/sp_min/aarch32/entrypoint.S +++ b/bl32/sp_min/aarch32/entrypoint.S @@ -1,5 +1,5 @@ /* - * Copyright (c) 2016-2022, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2016-2023, Arm Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ @@ -62,11 +62,8 @@ vector_base sp_min_vector_table * The Cold boot/Reset entrypoint for SP_MIN */ func sp_min_entrypoint -#if !RESET_TO_SP_MIN /* --------------------------------------------------------------- - * Preceding bootloader has populated r0 with a pointer to a - * 'bl_params_t' structure & r1 with a pointer to platform - * specific structure + * Stash the previous bootloader arguments r0 - r3 for later use. * --------------------------------------------------------------- */ mov r9, r0 @@ -74,6 +71,7 @@ func sp_min_entrypoint mov r11, r2 mov r12, r3 +#if !RESET_TO_SP_MIN /* --------------------------------------------------------------------- * For !RESET_TO_SP_MIN systems, only the primary CPU ever reaches * sp_min_entrypoint() during the cold boot flow, so the cold/warm boot @@ -91,11 +89,6 @@ func sp_min_entrypoint _init_c_runtime=1 \ _exception_vectors=sp_min_vector_table \ _pie_fixup_size=FIXUP_SIZE - - /* --------------------------------------------------------------------- - * Relay the previous bootloader's arguments to the platform layer - * --------------------------------------------------------------------- - */ #else /* --------------------------------------------------------------------- * For RESET_TO_SP_MIN systems which have a programmable reset address, @@ -111,24 +104,16 @@ func sp_min_entrypoint _init_c_runtime=1 \ _exception_vectors=sp_min_vector_table \ _pie_fixup_size=FIXUP_SIZE - - /* --------------------------------------------------------------------- - * For RESET_TO_SP_MIN systems, BL32 (SP_MIN) is the first bootloader - * to run so there's no argument to relay from a previous bootloader. - * Zero the arguments passed to the platform layer to reflect that. - * --------------------------------------------------------------------- - */ - mov r9, #0 - mov r10, #0 - mov r11, #0 - mov r12, #0 - #endif /* RESET_TO_SP_MIN */ #if SP_MIN_WITH_SECURE_FIQ route_fiq_to_sp_min r4 #endif + /* --------------------------------------------------------------------- + * Relay the previous bootloader's arguments to the platform layer + * --------------------------------------------------------------------- + */ mov r0, r9 mov r1, r10 mov r2, r11 -- cgit v1.2.3