On Tue, Jun 01, 2021 at 06:55:52PM +0200, Heinrich Schuchardt wrote:
On 6/1/21 6:22 PM, Marek Behún wrote:
On Tue, 1 Jun 2021 16:59:52 +0200 Patrick DELAUNAY patrick.delaunay@foss.st.com wrote:
Hi Marek,
I am trying to activate CONFIG_LTO for STMicroelectronics stm32mp15 platform
(stm32mp15_trusted_defconfig and stm32mp15_basic_defconfig).
The config stm32mp15_basic_defconfig, with SPL supported failed to boot
with gcc-arm-9.2-2019.12.
because a weak function is not correctly handle between
1/ ./arch/arm/lib/cache-cp15.c: 96
__weak void dram_bank_mmu_setup(int bank);
2/ the stm32mp implementation in
arch/arm/mach-stm32mp/cpu.c:62
void dram_bank_mmu_setup(int bank)
=> The used function in SPL is the cache library, not the stm32mp function.
and SPL boot it OK when I remove the function in the cache library...
And the issue is also solved with I use a more recent version
gcc-arm-10.2-2020.11 on my PC.
Do you see the same kind of issue for old version of gcc ?
Do you think CONFIG_LTO require a more recent version of gcc that
the minimal version required by U-Boot because I don't see this information
in the serie?
I only tried compiling with older versions in the CI.
On the devices for which I tested it I only compiled with newer gcc (10.2.0) since it is the stable version on my system.
But yeah, I suggest to use newer GCC for LTO.
Marek
gcc (Debian 11-20210327-1) 11.0.1 compiles stm32mp15_basic_defconfig with CONFIG_LTO=y.
It's run-time not compile time that shows the problem however as gcc-9.x sounds like it has a problem with LTO and weak functions.