BL2_AT_EL3: Enable pointer authentication support
The size increase after enabling options related to ARMv8.3-PAuth is:
+----------------------------+-------+-------+-------+--------+
| | text | bss | data | rodata |
+----------------------------+-------+-------+-------+--------+
| CTX_INCLUDE_PAUTH_REGS = 1 | +44 | +0 | +0 | +0 |
| | 0.2% | | | |
+----------------------------+-------+-------+-------+--------+
| ENABLE_PAUTH = 1 | +712 | +0 | +16 | +0 |
| | 3.1% | | 0.9% | |
+----------------------------+-------+-------+-------+--------+
The results are valid for the following build configuration:
make PLAT=fvp SPD=tspd DEBUG=1 \
BL2_AT_EL3=1 \
CTX_INCLUDE_PAUTH_REGS=1 \
ENABLE_PAUTH=1
Change-Id: I1c0616e7dea30962a92b4fd113428bc30a018320
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/bl2/aarch32/bl2_el3_entrypoint.S b/bl2/aarch32/bl2_el3_entrypoint.S
index cc846dd..35da133 100644
--- a/bl2/aarch32/bl2_el3_entrypoint.S
+++ b/bl2/aarch32/bl2_el3_entrypoint.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -36,8 +36,11 @@
mov r2, r11
mov r3, r12
- bl bl2_el3_early_platform_setup
- bl bl2_el3_plat_arch_setup
+ /* ---------------------------------------------
+ * Perform BL2 setup
+ * ---------------------------------------------
+ */
+ bl bl2_el3_setup
/* ---------------------------------------------
* Jump to main function.
diff --git a/bl2/aarch64/bl2_el3_entrypoint.S b/bl2/aarch64/bl2_el3_entrypoint.S
index 16b7c0d..d1e4247 100644
--- a/bl2/aarch64/bl2_el3_entrypoint.S
+++ b/bl2/aarch64/bl2_el3_entrypoint.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -29,16 +29,31 @@
_init_c_runtime=1 \
_exception_vectors=bl2_el3_exceptions
- /*
+ /* ---------------------------------------------
* Restore parameters of boot rom
+ * ---------------------------------------------
*/
mov x0, x20
mov x1, x21
mov x2, x22
mov x3, x23
+ /* ---------------------------------------------
+ * Perform BL2 setup
+ * ---------------------------------------------
+ */
+ bl bl2_el3_setup
+
- bl bl2_el3_early_platform_setup
- bl bl2_el3_plat_arch_setup
+ /* ---------------------------------------------
+ * Enable pointer authentication
+ * ---------------------------------------------
+ */
+#if ENABLE_PAUTH
+ mrs x0, sctlr_el3
+ orr x0, x0, #SCTLR_EnIA_BIT
+ msr sctlr_el3, x0
+ isb
+#endif /* ENABLE_PAUTH */
/* ---------------------------------------------
* Jump to main function.
@@ -55,16 +70,29 @@
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.
- */
+ /* ---------------------------------------------
+ * 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
+ /* ---------------------------------------------
+ * Disable pointer authentication before jumping to BL31 or that will
+ * cause an authentication failure during the early platform init.
+ * ---------------------------------------------
+ */
+#if ENABLE_PAUTH
+ mrs x0, sctlr_el3
+ bic x0, x0, #SCTLR_EnIA_BIT
+ msr sctlr_el3, x0
+ isb
+#endif /* ENABLE_PAUTH */
+
ldp x0, x1, [x20, #ENTRY_POINT_INFO_PC_OFFSET]
msr elr_el3, x0
msr spsr_el3, x1
diff --git a/bl2/bl2_main.c b/bl2/bl2_main.c
index e7ab7bb..7d8d60c 100644
--- a/bl2/bl2_main.c
+++ b/bl2/bl2_main.c
@@ -21,6 +21,7 @@
#define NEXT_IMAGE "BL31"
#endif
+#if !BL2_AT_EL3
/*******************************************************************************
* Setup function for BL2.
******************************************************************************/
@@ -43,6 +44,31 @@
/* Perform late platform-specific setup */
bl2_plat_arch_setup();
}
+
+#else /* if BL2_AT_EL3 */
+/*******************************************************************************
+ * Setup function for BL2 when BL2_AT_EL3=1.
+ ******************************************************************************/
+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_el3_early_platform_setup(arg0, arg1, arg2, arg3);
+
+#ifdef AARCH64
+ /*
+ * Update pointer authentication key before the MMU is enabled. It is
+ * saved in the rodata section, that can be writen before enabling the
+ * MMU. This function must be called after the console is initialized
+ * in the early platform setup.
+ */
+ bl_handle_pauth();
+#endif /* AARCH64 */
+
+ /* Perform late platform-specific setup */
+ bl2_el3_plat_arch_setup();
+}
+#endif /* BL2_AT_EL3 */
/*******************************************************************************
* The only thing to do in BL2 is to load further images and pass control to
@@ -88,11 +114,11 @@
* 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
+#else /* if BL2_AT_EL3 */
NOTICE("BL2: Booting " NEXT_IMAGE "\n");
print_entry_point_info(next_bl_ep_info);
console_flush();
bl2_run_next_image(next_bl_ep_info);
-#endif
+#endif /* BL2_AT_EL3 */
}
diff --git a/include/bl2/bl2.h b/include/bl2/bl2.h
index b3f9a87..73f5ac7 100644
--- a/include/bl2/bl2.h
+++ b/include/bl2/bl2.h
@@ -11,6 +11,8 @@
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);
void bl2_main(void);
#endif /* BL2_H */