feat(rme): run BL2 in root world when FEAT_RME is enabled
This patch enables BL2 to run in root world (EL3) which is
needed as per the security model of RME-enabled systems.
Using the existing BL2_AT_EL3 TF-A build option is not convenient
because that option assumes TF-A BL1 doesn't exist, which is not
the case for RME-enabled systems. For the purposes of RME, we use
a normal BL1 image but we also want to run BL2 in EL3 as normally as
possible, therefore rather than use the special bl2_entrypoint
function in bl2_el3_entrypoint.S, we use a new bl2_entrypoint
function (in bl2_rme_entrypoint.S) which doesn't need reset or
mailbox initialization code seen in the el3_entrypoint_common macro.
The patch also cleans up bl2_el3_entrypoint.S, moving the
bl2_run_next_image function to its own file to avoid duplicating
code.
Signed-off-by: Zelalem Aweke <zelalem.aweke@arm.com>
Change-Id: I99821b4cd550cadcb701f4c0c4dc36da81c7ef55
diff --git a/bl2/aarch64/bl2_el3_entrypoint.S b/bl2/aarch64/bl2_el3_entrypoint.S
index 4eab39c..45bac7d 100644
--- a/bl2/aarch64/bl2_el3_entrypoint.S
+++ b/bl2/aarch64/bl2_el3_entrypoint.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2021, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -12,8 +12,6 @@
#include <el3_common_macros.S>
.globl bl2_entrypoint
- .globl bl2_el3_run_image
- .globl bl2_run_next_image
#if BL2_IN_XIP_MEM
#define FIXUP_SIZE 0
@@ -72,36 +70,3 @@
*/
no_ret plat_panic_handler
endfunc bl2_entrypoint
-
-func bl2_run_next_image
- mov x20,x0
- /* ---------------------------------------------
- * MMU needs to be disabled because both BL2 and BL31 execute
- * in EL3, and therefore share the same address space.
- * BL31 will initialize the address space according to its
- * own requirement.
- * ---------------------------------------------
- */
- bl disable_mmu_icache_el3
- tlbi alle3
- bl bl2_el3_plat_prepare_exit
-
-#if ENABLE_PAUTH
- /* ---------------------------------------------
- * Disable pointer authentication before jumping
- * to next boot image.
- * ---------------------------------------------
- */
- bl pauth_disable_el3
-#endif /* ENABLE_PAUTH */
-
- ldp x0, x1, [x20, #ENTRY_POINT_INFO_PC_OFFSET]
- msr elr_el3, x0
- msr spsr_el3, x1
-
- ldp x6, x7, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x30)]
- ldp x4, x5, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x20)]
- ldp x2, x3, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x10)]
- ldp x0, x1, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x0)]
- exception_return
-endfunc bl2_run_next_image