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/aarch32/bl2_el3_entrypoint.S b/bl2/aarch32/bl2_el3_entrypoint.S
index 7e85551..40154aa 100644
--- a/bl2/aarch32/bl2_el3_entrypoint.S
+++ b/bl2/aarch32/bl2_el3_entrypoint.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2021, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -10,7 +10,6 @@
#include <el3_common_macros.S>
.globl bl2_entrypoint
- .globl bl2_run_next_image
func bl2_entrypoint
@@ -56,37 +55,3 @@
no_ret plat_panic_handler
endfunc bl2_entrypoint
-
-func bl2_run_next_image
- mov r8,r0
-
- /*
- * MMU needs to be disabled because both BL2 and BL32 execute
- * in PL1, and therefore share the same address space.
- * BL32 will initialize the address space according to its
- * own requirement.
- */
- bl disable_mmu_icache_secure
- stcopr r0, TLBIALL
- dsb sy
- isb
- mov r0, r8
- bl bl2_el3_plat_prepare_exit
-
- /*
- * Extract PC and SPSR based on struct `entry_point_info_t`
- * and load it in LR and SPSR registers respectively.
- */
- ldr lr, [r8, #ENTRY_POINT_INFO_PC_OFFSET]
- ldr r1, [r8, #(ENTRY_POINT_INFO_PC_OFFSET + 4)]
- msr spsr_xc, r1
-
- /* Some BL32 stages expect lr_svc to provide the BL33 entry address */
- cps #MODE32_svc
- ldr lr, [r8, #ENTRY_POINT_INFO_LR_SVC_OFFSET]
- cps #MODE32_mon
-
- add r8, r8, #ENTRY_POINT_INFO_ARGS_OFFSET
- ldm r8, {r0, r1, r2, r3}
- exception_return
-endfunc bl2_run_next_image
diff --git a/bl2/aarch32/bl2_run_next_image.S b/bl2/aarch32/bl2_run_next_image.S
new file mode 100644
index 0000000..0b3554e
--- /dev/null
+++ b/bl2/aarch32/bl2_run_next_image.S
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <common/bl_common.h>
+
+ .globl bl2_run_next_image
+
+
+func bl2_run_next_image
+ mov r8,r0
+
+ /*
+ * MMU needs to be disabled because both BL2 and BL32 execute
+ * in PL1, and therefore share the same address space.
+ * BL32 will initialize the address space according to its
+ * own requirement.
+ */
+ bl disable_mmu_icache_secure
+ stcopr r0, TLBIALL
+ dsb sy
+ isb
+ mov r0, r8
+ bl bl2_el3_plat_prepare_exit
+
+ /*
+ * Extract PC and SPSR based on struct `entry_point_info_t`
+ * and load it in LR and SPSR registers respectively.
+ */
+ ldr lr, [r8, #ENTRY_POINT_INFO_PC_OFFSET]
+ ldr r1, [r8, #(ENTRY_POINT_INFO_PC_OFFSET + 4)]
+ msr spsr_xc, r1
+
+ /* Some BL32 stages expect lr_svc to provide the BL33 entry address */
+ cps #MODE32_svc
+ ldr lr, [r8, #ENTRY_POINT_INFO_LR_SVC_OFFSET]
+ cps #MODE32_mon
+
+ add r8, r8, #ENTRY_POINT_INFO_ARGS_OFFSET
+ ldm r8, {r0, r1, r2, r3}
+ exception_return
+endfunc bl2_run_next_image
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
diff --git a/bl2/aarch64/bl2_rme_entrypoint.S b/bl2/aarch64/bl2_rme_entrypoint.S
new file mode 100644
index 0000000..076e326
--- /dev/null
+++ b/bl2/aarch64/bl2_rme_entrypoint.S
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <platform_def.h>
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <common/bl_common.h>
+#include <el3_common_macros.S>
+
+ .globl bl2_entrypoint
+
+
+func bl2_entrypoint
+ /* Save arguments x0-x3 from previous Boot loader */
+ mov x20, x0
+ mov x21, x1
+ mov x22, x2
+ mov x23, x3
+
+ el3_entrypoint_common \
+ _init_sctlr=0 \
+ _warm_boot_mailbox=0 \
+ _secondary_cold_boot=0 \
+ _init_memory=0 \
+ _init_c_runtime=1 \
+ _exception_vectors=bl2_el3_exceptions \
+ _pie_fixup_size=0
+
+ /* ---------------------------------------------
+ * Restore parameters of boot rom
+ * ---------------------------------------------
+ */
+ mov x0, x20
+ mov x1, x21
+ mov x2, x22
+ mov x3, x23
+
+ /* ---------------------------------------------
+ * Perform BL2 setup
+ * ---------------------------------------------
+ */
+ bl bl2_setup
+
+#if ENABLE_PAUTH
+ /* ---------------------------------------------
+ * Program APIAKey_EL1 and enable pointer authentication.
+ * ---------------------------------------------
+ */
+ bl pauth_init_enable_el3
+#endif /* ENABLE_PAUTH */
+
+ /* ---------------------------------------------
+ * Jump to main function.
+ * ---------------------------------------------
+ */
+ bl bl2_main
+
+ /* ---------------------------------------------
+ * Should never reach this point.
+ * ---------------------------------------------
+ */
+ no_ret plat_panic_handler
+endfunc bl2_entrypoint
diff --git a/bl2/aarch64/bl2_run_next_image.S b/bl2/aarch64/bl2_run_next_image.S
new file mode 100644
index 0000000..f0a8be8
--- /dev/null
+++ b/bl2/aarch64/bl2_run_next_image.S
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <common/bl_common.h>
+
+ .globl bl2_run_next_image
+
+
+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
diff --git a/bl2/bl2.ld.S b/bl2/bl2.ld.S
index 37849c3..d332ec0 100644
--- a/bl2/bl2.ld.S
+++ b/bl2/bl2.ld.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2021, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -25,7 +25,11 @@
#if SEPARATE_CODE_AND_RODATA
.text . : {
__TEXT_START__ = .;
+#if ENABLE_RME
+ *bl2_rme_entrypoint.o(.text*)
+#else /* ENABLE_RME */
*bl2_entrypoint.o(.text*)
+#endif /* ENABLE_RME */
*(SORT_BY_ALIGNMENT(.text*))
*(.vectors)
. = ALIGN(PAGE_SIZE);
diff --git a/bl2/bl2.mk b/bl2/bl2.mk
index 735e7e0..54c73f5 100644
--- a/bl2/bl2.mk
+++ b/bl2/bl2.mk
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2021, Arm Limited and Contributors. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#
@@ -15,13 +15,24 @@
BL2_SOURCES += common/aarch64/early_exceptions.S
endif
-ifeq (${BL2_AT_EL3},0)
+ifeq (${ENABLE_RME},1)
+# Using RME, run BL2 at EL3
+BL2_SOURCES += bl2/${ARCH}/bl2_rme_entrypoint.S \
+ bl2/${ARCH}/bl2_el3_exceptions.S \
+ bl2/${ARCH}/bl2_run_next_image.S \
+
+BL2_LINKERFILE := bl2/bl2.ld.S
+
+else ifeq (${BL2_AT_EL3},0)
+# Normal operation, no RME, no BL2 at EL3
BL2_SOURCES += bl2/${ARCH}/bl2_entrypoint.S
BL2_LINKERFILE := bl2/bl2.ld.S
else
+# BL2 at EL3, no RME
BL2_SOURCES += bl2/${ARCH}/bl2_el3_entrypoint.S \
bl2/${ARCH}/bl2_el3_exceptions.S \
+ bl2/${ARCH}/bl2_run_next_image.S \
lib/cpus/${ARCH}/cpu_helpers.S \
lib/cpus/errata_report.c
diff --git a/bl2/bl2_main.c b/bl2/bl2_main.c
index d2de135..197c057 100644
--- a/bl2/bl2_main.c
+++ b/bl2/bl2_main.c
@@ -29,18 +29,18 @@
#define NEXT_IMAGE "BL32"
#endif
-#if !BL2_AT_EL3
+#if BL2_AT_EL3
/*******************************************************************************
- * Setup function for BL2.
+ * Setup function for BL2 when BL2_AT_EL3=1
******************************************************************************/
-void bl2_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
- u_register_t arg3)
+void bl2_el3_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
+ u_register_t arg3)
{
/* Perform early platform-specific setup */
- bl2_early_platform_setup2(arg0, arg1, arg2, arg3);
+ bl2_el3_early_platform_setup(arg0, arg1, arg2, arg3);
/* Perform late platform-specific setup */
- bl2_plat_arch_setup();
+ bl2_el3_plat_arch_setup();
#if CTX_INCLUDE_PAUTH_REGS
/*
@@ -50,19 +50,18 @@
assert(is_armv8_3_pauth_present());
#endif /* CTX_INCLUDE_PAUTH_REGS */
}
-
-#else /* if BL2_AT_EL3 */
+#else /* BL2_AT_EL3 */
/*******************************************************************************
- * Setup function for BL2 when BL2_AT_EL3=1.
+ * Setup function for BL2 when BL2_AT_EL3=0
******************************************************************************/
-void bl2_el3_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
- u_register_t arg3)
+void bl2_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
+ u_register_t arg3)
{
/* Perform early platform-specific setup */
- bl2_el3_early_platform_setup(arg0, arg1, arg2, arg3);
+ bl2_early_platform_setup2(arg0, arg1, arg2, arg3);
/* Perform late platform-specific setup */
- bl2_el3_plat_arch_setup();
+ bl2_plat_arch_setup();
#if CTX_INCLUDE_PAUTH_REGS
/*
@@ -115,7 +114,7 @@
measured_boot_finish();
#endif /* MEASURED_BOOT */
-#if !BL2_AT_EL3
+#if !BL2_AT_EL3 && !ENABLE_RME
#ifndef __aarch64__
/*
* For AArch32 state BL1 and BL2 share the MMU setup.
@@ -140,7 +139,7 @@
* be passed to next BL image as an argument.
*/
smc(BL1_SMC_RUN_IMAGE, (unsigned long)next_bl_ep_info, 0, 0, 0, 0, 0, 0);
-#else /* if BL2_AT_EL3 */
+#else /* if BL2_AT_EL3 || ENABLE_RME */
NOTICE("BL2: Booting " NEXT_IMAGE "\n");
print_entry_point_info(next_bl_ep_info);
console_flush();
@@ -153,5 +152,5 @@
#endif /* ENABLE_PAUTH */
bl2_run_next_image(next_bl_ep_info);
-#endif /* BL2_AT_EL3 */
+#endif /* BL2_AT_EL3 && ENABLE_RME */
}