Djam/arm-trusted-firmware
1
0
Fork 0
mirror of https://github.com/ARM-software/arm-trusted-firmware.git synced 2025-04-23 13:36:05 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

fix(bl32): avoid clearing argument registers in RESET_TO_SP_MIN case

Browse source 
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 <stephan@gerhold.net>
This commit is contained in:
Stephan Gerhold 2023-04-17 14:47:40 +02:00
parent cd0786c73e
commit 56055e87b0
1 changed files with 7 additions and 22 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

29
bl32/sp_min/aarch32/entrypoint.S
View file

@ -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