feat(bl2): add support to separate no-loadable sections
Add new options SEPARATE_BL2_NOLOAD_REGION to separate no-loadable
sections (.bss, stack, page tables) to a ram region specified
by BL2_NOLOAD_START and BL2_NOLOAD_LIMIT.
Signed-off-by: Jiafei Pan <Jiafei.Pan@nxp.com>
Change-Id: I844ee0fc405474af0aff978d292c826fbe0a82fd
diff --git a/Makefile b/Makefile
index fb50f0c..95c9075 100644
--- a/Makefile
+++ b/Makefile
@@ -1021,6 +1021,7 @@
RESET_TO_BL31 \
SAVE_KEYS \
SEPARATE_CODE_AND_RODATA \
+ SEPARATE_BL2_NOLOAD_REGION \
SEPARATE_NOBITS_REGION \
SPIN_ON_BL1_EXIT \
SPM_MM \
@@ -1136,6 +1137,7 @@
RAS_EXTENSION \
RESET_TO_BL31 \
SEPARATE_CODE_AND_RODATA \
+ SEPARATE_BL2_NOLOAD_REGION \
SEPARATE_NOBITS_REGION \
RECLAIM_INIT_CODE \
SPD_${SPD} \
diff --git a/bl2/bl2_el3.ld.S b/bl2/bl2_el3.ld.S
index bc1794c..6aa7afd 100644
--- a/bl2/bl2_el3.ld.S
+++ b/bl2/bl2_el3.ld.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2022, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -17,6 +17,11 @@
RAM (rwx): ORIGIN = BL2_RW_BASE, LENGTH = BL2_RW_LIMIT - BL2_RW_BASE
#else
RAM (rwx): ORIGIN = BL2_BASE, LENGTH = BL2_LIMIT - BL2_BASE
+#if SEPARATE_BL2_NOLOAD_REGION
+ RAM_NOLOAD (rw!a): ORIGIN = BL2_NOLOAD_START, LENGTH = BL2_NOLOAD_LIMIT - BL2_NOLOAD_START
+#else
+#define RAM_NOLOAD RAM
+#endif
#endif
}
@@ -106,9 +111,18 @@
__DATA_RAM_END__ = __DATA_END__;
RELA_SECTION >RAM
- STACK_SECTION >RAM
- BSS_SECTION >RAM
- XLAT_TABLE_SECTION >RAM
+#if SEPARATE_BL2_NOLOAD_REGION
+ SAVED_ADDR = .;
+ . = BL2_NOLOAD_START;
+ __BL2_NOLOAD_START__ = .;
+#endif
+ STACK_SECTION >RAM_NOLOAD
+ BSS_SECTION >RAM_NOLOAD
+ XLAT_TABLE_SECTION >RAM_NOLOAD
+#if SEPARATE_BL2_NOLOAD_REGION
+ __BL2_NOLOAD_END__ = .;
+ . = SAVED_ADDR;
+#endif
#if USE_COHERENT_MEM
/*
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index a34bb3c..adc05e6 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -647,6 +647,13 @@
``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS
sections are placed in RAM immediately following the loaded firmware image.
+- ``SEPARATE_BL2_NOLOAD_REGION``: Setting this option to ``1`` allows the
+ NOLOAD sections of BL2 (.bss, stacks, page tables) to be allocated in RAM
+ discontiguous from loaded firmware images. When set, the platform need to
+ provide definitions of ``BL2_NOLOAD_START`` and ``BL2_NOLOAD_LIMIT``. This
+ flag is disabled by default and NOLOAD sections are placed in RAM immediately
+ following the loaded firmware image.
+
- ``SMC_PCI_SUPPORT``: This option allows platforms to handle PCI configuration
access requests via a standard SMCCC defined in `DEN0115`_. When combined with
UEFI+ACPI this can provide a certain amount of OS forward compatibility
@@ -961,7 +968,7 @@
--------------
-*Copyright (c) 2019-2021, Arm Limited. All rights reserved.*
+*Copyright (c) 2019-2022, Arm Limited. All rights reserved.*
.. _DEN0115: https://developer.arm.com/docs/den0115/latest
.. _PSA FW update specification: https://developer.arm.com/documentation/den0118/a/
diff --git a/include/arch/aarch32/el3_common_macros.S b/include/arch/aarch32/el3_common_macros.S
index ad2a039..8b6765a 100644
--- a/include/arch/aarch32/el3_common_macros.S
+++ b/include/arch/aarch32/el3_common_macros.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2022, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -398,6 +398,12 @@
ldr r1, =__RW_END__
sub r1, r1, r0
bl inv_dcache_range
+#if defined(IMAGE_BL2) && SEPARATE_BL2_NOLOAD_REGION
+ ldr r0, =__BL2_NOLOAD_START__
+ ldr r1, =__BL2_NOLOAD_END__
+ sub r1, r1, r0
+ bl inv_dcache_range
+#endif
#endif
/*
diff --git a/include/arch/aarch64/el3_common_macros.S b/include/arch/aarch64/el3_common_macros.S
index d47244e..de2b931 100644
--- a/include/arch/aarch64/el3_common_macros.S
+++ b/include/arch/aarch64/el3_common_macros.S
@@ -469,6 +469,14 @@
sub x1, x1, x0
bl inv_dcache_range
#endif
+#if defined(IMAGE_BL2) && SEPARATE_BL2_NOLOAD_REGION
+ adrp x0, __BL2_NOLOAD_START__
+ add x0, x0, :lo12:__BL2_NOLOAD_START__
+ adrp x1, __BL2_NOLOAD_END__
+ add x1, x1, :lo12:__BL2_NOLOAD_END__
+ sub x1, x1, x0
+ bl inv_dcache_range
+#endif
#endif
adrp x0, __BSS_START__
add x0, x0, :lo12:__BSS_START__
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index b39dcf4..910ffdf 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -250,6 +250,10 @@
# separate memory region, which may be discontiguous from the rest of BL31.
SEPARATE_NOBITS_REGION := 0
+# Put BL2 NOLOAD sections (.bss, stacks, page tables) in a separate memory
+# region, platform Makefile is free to override this value.
+SEPARATE_BL2_NOLOAD_REGION := 0
+
# If the BL31 image initialisation code is recalimed after use for the secondary
# cores stack
RECLAIM_INIT_CODE := 0