BL2_AT_EL3: add PIE support
This implementation simply mimics that of BL31.
I did not implement the ENABLE_PIE support for BL2_IN_XIP_MEM=1 case.
It would make the linker script a bit uglier.
Change-Id: If3215abd99f2758dfb232e44b50320d04eba808b
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/Makefile b/Makefile
index 89653b7..0193c29 100644
--- a/Makefile
+++ b/Makefile
@@ -464,6 +464,12 @@
endif
ifeq ($(ENABLE_PIE),1)
+ifeq ($(BL2_AT_EL3),1)
+ifneq ($(BL2_IN_XIP_MEM),1)
+ BL2_CFLAGS += -fpie
+ BL2_LDFLAGS += $(PIE_LDFLAGS)
+endif
+endif
BL31_CFLAGS += -fpie
BL31_LDFLAGS += $(PIE_LDFLAGS)
endif
diff --git a/bl2/aarch64/bl2_el3_entrypoint.S b/bl2/aarch64/bl2_el3_entrypoint.S
index 2ca6acf..4eab39c 100644
--- a/bl2/aarch64/bl2_el3_entrypoint.S
+++ b/bl2/aarch64/bl2_el3_entrypoint.S
@@ -4,6 +4,8 @@
* SPDX-License-Identifier: BSD-3-Clause
*/
+#include <platform_def.h>
+
#include <arch.h>
#include <asm_macros.S>
#include <common/bl_common.h>
@@ -13,6 +15,12 @@
.globl bl2_el3_run_image
.globl bl2_run_next_image
+#if BL2_IN_XIP_MEM
+#define FIXUP_SIZE 0
+#else
+#define FIXUP_SIZE ((BL2_LIMIT) - (BL2_BASE))
+#endif
+
func bl2_entrypoint
/* Save arguments x0-x3 from previous Boot loader */
mov x20, x0
@@ -27,7 +35,7 @@
_init_memory=1 \
_init_c_runtime=1 \
_exception_vectors=bl2_el3_exceptions \
- _pie_fixup_size=0
+ _pie_fixup_size=FIXUP_SIZE
/* ---------------------------------------------
* Restore parameters of boot rom
diff --git a/bl2/bl2_el3.ld.S b/bl2/bl2_el3.ld.S
index dc398eb..b6570ee 100644
--- a/bl2/bl2_el3.ld.S
+++ b/bl2/bl2_el3.ld.S
@@ -69,6 +69,16 @@
KEEP(*(cpu_ops))
__CPU_OPS_END__ = .;
+ /*
+ * Keep the .got section in the RO section as it is patched
+ * prior to enabling the MMU and having the .got in RO is better for
+ * security. GOT is a table of addresses so ensure 8-byte alignment.
+ */
+ . = ALIGN(8);
+ __GOT_START__ = .;
+ *(.got)
+ __GOT_END__ = .;
+
. = ALIGN(PAGE_SIZE);
__RODATA_END__ = .;
} >ROM
@@ -100,6 +110,16 @@
KEEP(*(.img_parser_lib_descs))
__PARSER_LIB_DESCS_END__ = .;
+ /*
+ * Keep the .got section in the RO section as it is patched
+ * prior to enabling the MMU and having the .got in RO is better for
+ * security. GOT is a table of addresses so ensure 8-byte alignment.
+ */
+ . = ALIGN(8);
+ __GOT_START__ = .;
+ *(.got)
+ __GOT_END__ = .;
+
*(.vectors)
__RO_END_UNALIGNED__ = .;
/*
@@ -139,6 +159,17 @@
__DATA_RAM_END__ = .;
} >RAM AT>ROM
+ /*
+ * .rela.dyn needs to come after .data for the read-elf utility to parse
+ * this section correctly. Ensure 8-byte alignment so that the fields of
+ * RELA data structure are aligned.
+ */
+ . = ALIGN(8);
+ __RELA_START__ = .;
+ .rela.dyn . : {
+ } >RAM
+ __RELA_END__ = .;
+
stacks (NOLOAD) : {
__STACKS_START__ = .;
*(tzfw_normal_stacks)
@@ -195,6 +226,10 @@
__RW_END__ = .;
__BL2_END__ = .;
+ /DISCARD/ : {
+ *(.dynsym .dynstr .hash .gnu.hash)
+ }
+
#if BL2_IN_XIP_MEM
__BL2_RAM_START__ = ADDR(.data);
__BL2_RAM_END__ = .;
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index d7bb044..cac7e31 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -213,7 +213,7 @@
- ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE)
support within generic code in TF-A. This option is currently only supported
- in BL31. Default is 0.
+ in BL2_AT_EL3 and BL31. Default is 0.
- ``ENABLE_PMF``: Boolean option to enable support for optional Performance
Measurement Framework(PMF). Default is 0.
