Hi Tom, On Thu, 5 Jun 2025 at 17:46, Tom Rini <tr...@konsulko.com> wrote: > > On Thu, Jun 05, 2025 at 04:52:20PM -0400, Raymond Mao wrote: > > Hi Tom, > > > > On Thu, 5 Jun 2025 at 16:01, Tom Rini <tr...@konsulko.com> wrote: > > > > > > On Thu, Jun 05, 2025 at 03:45:00PM -0400, Raymond Mao wrote: > > > > Hi Tom, > > > > > > > > On Thu, 5 Jun 2025 at 13:15, Tom Rini <tr...@konsulko.com> wrote: > > > > > > > > > > On Tue, Jun 03, 2025 at 07:42:55AM -0700, Raymond Mao wrote: > > > > > > > > > > > MbedTLS bignum module needs '__udivti3' which is a 128-bit division > > > > > > function provided by the compiler runtime, typically libgcc for GCC > > > > > > or > > > > > > clang_rt.builtins for Clang. > > > > > > Thus 'clang_rt.builtins' library is required when building using > > > > > > Clang. > > > > > > > > > > > > This patch supports the location layout of clang_rt.builtins > > > > > > libraries > > > > > > from both LLVM pre-15 pattern [1] and post-15(up to 20) pattern [2]. > > > > > > > > > > > > As a fact that starts from LLVM 20, no official prebuilt > > > > > > multi-targets > > > > > > are included and users might need to cross-built it from source. > > > > > > [3] is > > > > > > an example of instructions for building. > > > > > > > > > > > > [1] > > > > > > <INST_DIR>/lib/clang/<REV>/lib/linux/libclang_rt.builtins-<ARCH>.a > > > > > > E.g. > > > > > > lib/clang/14.0.0/lib/linux/libclang_rt.builtins-aarch64.a > > > > > > lib/clang/14.0.0/lib/linux/libclang_rt.builtins-x86_64.a > > > > > > > > > > > > [2] > > > > > > <INST_DIR>/lib/clang/<REV_MAJOR>/lib/<CROSSTOOL>/libclang_rt.builtins.a > > > > > > E.g. > > > > > > lib/clang/20/lib/aarch64-none-linux-gnu/libclang_rt.builtins.a > > > > > > lib/clang/20/lib/x86_64-unknown-linux-gnu/libclang_rt.builtins.a > > > > > > > > > > > > [3] > > > > > > git clone https://github.com/llvm/llvm-project.git > > > > > > cd llvm-project > > > > > > git checkout -b llvmorg-20.1.6 llvmorg-20.1.6 > > > > > > mkdir build-builtin && cd build-builtin > > > > > > cmake -G Ninja ../llvm \ > > > > > > -DCMAKE_BUILD_TYPE=Release \ > > > > > > -DCMAKE_C_COMPILER=clang \ > > > > > > -DLLVM_ENABLE_PROJECTS="clang" \ > > > > > > -DLLVM_ENABLE_RUNTIMES="compiler-rt" \ > > > > > > -DLLVM_TARGETS_TO_BUILD="X86;AArch64" \ > > > > > > -DLLVM_BUILTIN_TARGETS=\ > > > > > > "x86_64-unknown-linux-gnu;aarch64-none-linux-gnu" \ > > > > > > -DBUILTINS_aarch64-none-linux-gnu_CMAKE_SYSTEM_NAME=Linux \ > > > > > > -DBUILTINS_aarch64-none-linux-gnu_CMAKE_C_COMPILER=\ > > > > > > <YOUR_TOOLCHAIN_GCC> \ > > > > > > -DBUILTINS_aarch64-none-linux-gnu_CMAKE_ASM_COMPILER=\ > > > > > > <YOUR_TOOLCHAIN_GCC> \ > > > > > > -DBUILTINS_aarch64-none-linux-gnu_CMAKE_SYSROOT=\ > > > > > > <YOUR_TOOLCHAIN_LIBC_DIR> \ > > > > > > -DCOMPILER_RT_BUILD_BUILTINS=ON \ > > > > > > -DCOMPILER_RT_BUILD_SANITIZERS=OFF \ > > > > > > -DCOMPILER_RT_BUILD_XRAY=OFF \ > > > > > > -DCOMPILER_RT_BUILD_LIBFUZZER=OFF \ > > > > > > -DCOMPILER_RT_BUILD_PROFILE=OFF \ > > > > > > -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR> \ > > > > > > -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=OFF > > > > > > ninja builtins > > > > > > sudo ninja install > > > > > > > > > > > > Fixes: 13de8483388c ("mbedtls: add mbedtls into the build system") > > > > > > Signed-off-by: Raymond Mao <raymond....@linaro.org> > > > > > > > > > > I think that newer versions don't even ship this moves us further away > > > > > from a solution here as all of the logic. I think we need to look at > > > > > the > > > > > suggestion of just importing the assembly version of the function. > > > > > > > > But, the assembly versions are architecture-specific, do you want a > > > > portable C code for it? > > > > > > Is it easily done in C? If not, we can just try and make it clear what > > > needs to be pulled out of LLVM sources if/when another platform > > > encounters the problem. > > > > > But maybe we can ask the LLVM project owner why they removed the > > prebuilt multi-targets since 20.0.0. > > May current patch can support multiple target layouts of pre-15 and > > post-15 patterns (I believe they will keep the one of post-15 for the > > future), if they can provide the prebuilt multi-targets via package > > managers or release tarballs then it is the best solution. > > In the future we might need other functions from those libraries and > > implementing it in U-Boot is not a good choice IMO. > > I think adding all of that logic to the Makefile is taking us down the > wrong path. Looking at the kernel, they're working with LLVM to be able > to disable these 128bit intrinsics currently (as part of rust support). > So hopefully we just need some temporary workaround until things get > fixed upstream. > I will try to implement a C code function as a temporary solution and be back shortly.
Raymond > -- > Tom
