When I tried ENABLE_PIE for my PLAT=uniphier platform, BL31 crashed
at its entry. When it is built with ENABLE_PIE=1, some sections are
inserted before the executable code.
$ make PLAT=uniphier CROSS_COMPILE=aarch64-linux-gnu- ENABLE_PIE=1 bl31
$ aarch64-linux-gnu-objdump -h build/uniphier/release/bl31/bl31.elf | head -n 13
build/uniphier/release/bl31/bl31.elf: file format elf64-littleaarch64
Sections:
Idx Name Size VMA LMA File off Algn
0 .dynsym 000002a0 0000000081000000 0000000081000000 00010000 2**3
CONTENTS, ALLOC, LOAD, READONLY, DATA
1 .dynstr 000002a0 00000000810002a0 00000000810002a0 000102a0 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
2 .hash 00000124 0000000081000540 0000000081000540 00010540 2**3
CONTENTS, ALLOC, LOAD, READONLY, DATA
3 ro 0000699c 0000000081000664 0000000081000664 00010664 2**11
CONTENTS, ALLOC, LOAD, CODE
The previous stage loader generally jumps over to the base address of
BL31, where no valid instruction exists.
I checked the linker script of Linux (arch/arm64/kernel/vmlinux.lds.S)
and U-Boot (arch/arm/cpu/armv8/u-boot.lds), both of which support
relocation. They simply discard those sections.
Do similar in TF-A too.
Change-Id: I6c33e9143856765d4ffa24f3924b0ab51a17cde9
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
511046eaa2