CC u-boot mailing list to make people aware of the discussion.
By the way, I also noticed that, the final linking command is using: '''-pie -Bstatic --no-dynamic-linker''' And there are self-relocating code in Start.S.
BUT it is not included when u-boot is not configured using "POSITION_INDEPENDENT" Which means, PIE feature cannot be used at load time. I am not sure about the code design and use cases, but '''LDFLAGS_u-boot += -pie''' may need to be guarded with '''CONFIG_POSITION_INDEPENDENT''' as well? Otherwise what is the purpose of pie without processing the dynamic relocations?
I tried to do that, and with some fixes in other places to change the checks for relocations, it could generate a binary without any relocations. Though, I am NOT sure about the CORRECTNESS of the binary.
In the original code, R_AARCH64_ABS32 relocation is used to resolve an address at static linking time. It seems works fine originally (which doesn't mean it is not bugous). I assume it is because, no one is trying to use pie feature really.
If people is using pie feature to load the binary in a different address, proper relocations are required, as well as the self-relocating code.
The linker won't generate a dynamic RELATIVE relocation for _AARCH64_ABS32. SO the address in the table won't be updated by the fixup code. However, bfd linker will generate a dynamic RELATIVE relocation for R_AARCH64_ABS64 relocation, and it could be processed by self-relocating code, taking the load address into account.
Regards, Renlin
On Tue, Oct 2, 2018 at 11:45 AM Renlin Li renlin.dev@gmail.com wrote:
Hi Meng,
Thanks for raising the issue! I could reproduce the issue with the information you gave.
It seems to me that, the change I made earlier catches an issue here. in /arch/arm/cpu/armv8/psci.S
*/* PSCI function and ID table definition*/* *#define PSCI_TABLE(__id, __fn) *
- .word __id; *
- .word __fn*
"*.word*" is used to hold the address of a function.
The toolchain you used is aarch64-linux, which by default supports LP64 ABI. This means Long and void * (pointer) data type is 64-bit.
IIUC, a "*.xword*" should be used instead. Otherwise, you should use ILP32 ABI. But be aware, the support for ILP32 might not be complete.
Regards, Renlin
Hi All, Could you please help to have a look whether below issue is valuable? I got u-boot source code from https://github.com/u-boot/u-boot.git, branch = is master. I got toolchain from https://mirrors.edge.kernel.org/pub/tools/crosstool/fi= les/bin/x86_64/8.1.0/ I built stratix10(socfpga) platform with below commands: export CROSS_COMPILE=3Dxxx/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux=
export ARCH=3Darm64 make mrproper make socfpga_stratix10_defconfig make menuconfig, and then enable CONFIG_ARMV8_PSCI make there will be below error: LD u-boot
/home/wrsadmin/Project/Native/SDK/Altera-Arria-10/gcc-8.1.0-nolibc/aarch64-= linux/bin/aarch64-linux-ld.bfd: arch/arm/cpu/armv8/built-in.o: relocation R= _AARCH64_ABS32 against `psci_cpu_suspend' can not be used when making a sha= red object