Hi Jerome,
On Wed, 28 May 2025 at 11:37, Jerome Forissier
<jerome.foriss...@linaro.org> wrote:
>
>
>
> On 5/28/25 17:22, Raymond Mao wrote:
> > Hi Jerome,
> >
> > On Wed, 28 May 2025 at 04:25, Jerome Forissier
> > <jerome.foriss...@linaro.org> wrote:
> >>
> >> Hi Rayond,
> >>
> >> On 5/27/25 23:05, 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.
> >>
> >> How do you reproduce the problem? Can you give the config and build
> >> command you are using?
> >>
> > I am using this:
> > CROSS_COMPILE=aarch64-none-linux-gnu- make O=out CC="clang -target
> > aarch64-none-linux-gnu" all
> >
> >>>
> >>> Fixes: 13de8483388c ("mbedtls: add mbedtls into the build system")
> >>> Signed-off-by: Raymond Mao <raymond....@linaro.org>
> >>> ---
> >>> Makefile | 6 +++++-
> >>> 1 file changed, 5 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/Makefile b/Makefile
> >>> index f88684947ee..16506dcaec6 100644
> >>> --- a/Makefile
> >>> +++ b/Makefile
> >>> @@ -37,7 +37,6 @@ else ifeq ("riscv32", $(MK_ARCH))
> >>> else ifeq ("riscv64", $(MK_ARCH))
> >>> export HOST_ARCH=$(HOST_ARCH_RISCV64)
> >>> endif
> >>> -undefine MK_ARCH
> >>>
> >>> # Avoid funny character set dependencies
> >>> unexport LC_ALL
> >>> @@ -915,8 +914,13 @@ PLATFORM_LIBGCC = arch/$(ARCH)/lib/lib.a
> >>> else
> >>> ifndef CONFIG_CC_IS_CLANG
> >>> PLATFORM_LIBGCC := -L $(shell dirname `$(CC) $(c_flags)
> >>> -print-libgcc-file-name`) -lgcc
> >>> +else ifeq ($(CONFIG_RSA_PUBLIC_KEY_PARSER_MBEDTLS),y)
> >>> +# mbedtls bignum needs '__udivti3' - a 128-bit division function that's
> >>> provided by clang-rt.
> >>> +CLANG_RT_DIR := $(shell $(CC) --print-resource-dir)/lib/linux
> >>> +PLATFORM_LIBGCC := -L$(CLANG_RT_DIR) -lclang_rt.builtins-$(MK_ARCH)
> >>
> >> I'm afraid this won't work when cross-compiling because the compiler-rt
> >> builtins libraries are usually not installed with the compiler.
> >> For example on my Ubuntu 24.04 machine:
> >>
> >> $ clang --version
> >> Ubuntu clang version 18.1.3 (1ubuntu1)
> >> Target: x86_64-pc-linux-gnu
> >> Thread model: posix
> >> InstalledDir: /usr/bin
> >> $ clang --print-targets
> >>
> >> Registered Targets:
> >> aarch64 - AArch64 (little endian)
> >> aarch64_32 - AArch64 (little endian ILP32)
> >> aarch64_be - AArch64 (big endian)
> >> amdgcn - AMD GCN GPUs
> >> arm - ARM
> >> arm64 - ARM64 (little endian)
> >> arm64_32 - ARM64 (little endian ILP32)
> >> armeb - ARM (big endian)
> >> avr - Atmel AVR Microcontroller
> >> bpf - BPF (host endian)
> >> bpfeb - BPF (big endian)
> >> bpfel - BPF (little endian)
> >> hexagon - Hexagon
> >> lanai - Lanai
> >> loongarch32 - 32-bit LoongArch
> >> loongarch64 - 64-bit LoongArch
> >> m68k - Motorola 68000 family
> >> mips - MIPS (32-bit big endian)
> >> mips64 - MIPS (64-bit big endian)
> >> mips64el - MIPS (64-bit little endian)
> >> mipsel - MIPS (32-bit little endian)
> >> msp430 - MSP430 [experimental]
> >> nvptx - NVIDIA PTX 32-bit
> >> nvptx64 - NVIDIA PTX 64-bit
> >> ppc32 - PowerPC 32
> >> ppc32le - PowerPC 32 LE
> >> ppc64 - PowerPC 64
> >> ppc64le - PowerPC 64 LE
> >> r600 - AMD GPUs HD2XXX-HD6XXX
> >> riscv32 - 32-bit RISC-V
> >> riscv64 - 64-bit RISC-V
> >> sparc - Sparc
> >> sparcel - Sparc LE
> >> sparcv9 - Sparc V9
> >> systemz - SystemZ
> >> thumb - Thumb
> >> thumbeb - Thumb (big endian)
> >> ve - VE
> >> wasm32 - WebAssembly 32-bit
> >> wasm64 - WebAssembly 64-bit
> >> x86 - 32-bit X86: Pentium-Pro and above
> >> x86-64 - 64-bit X86: EM64T and AMD64
> >> xcore - XCore
> >> xtensa - Xtensa 32
> >> $ clang --print-resource-dir
> >> /usr/lib/llvm-18/lib/clang/18
> >> $ ls /usr/lib/llvm-18/lib/clang/18/lib/linux/libclang_rt.builtins*
> >> /usr/lib/llvm-18/lib/clang/18/lib/linux/libclang_rt.builtins-i386.a
> >> /usr/lib/llvm-18/lib/clang/18/lib/linux/libclang_rt.builtins-x86_64.a
> >>
> >>
> >> Are you doing cross compilation for arm or arm64? Did you have to
> >> install the compiler-rt libraries separately from the compiler?
> >>
> > I installed clang manually.
> >
> > This is what I have:
> > $ which clang
> > /home/raymond/toolchain/clang-12.0.0/bin/clang
> > $ clang --version
> > clang version 12.0.0
> > Target: x86_64-unknown-linux-gnu
> > Thread model: posix
> > InstalledDir: /home/raymond/toolchain/clang-12.0.0/bin
> > $ clang --print-targets
> > Registered Targets:
> > aarch64 - AArch64 (little endian)
> > aarch64_32 - AArch64 (little endian ILP32)
> > aarch64_be - AArch64 (big endian)
> > amdgcn - AMD GCN GPUs
> > arm - ARM
> > arm64 - ARM64 (little endian)
> > arm64_32 - ARM64 (little endian ILP32)
> > armeb - ARM (big endian)
> > avr - Atmel AVR Microcontroller
> > bpf - BPF (host endian)
> > bpfeb - BPF (big endian)
> > bpfel - BPF (little endian)
> > hexagon - Hexagon
> > lanai - Lanai
> > mips - MIPS (32-bit big endian)
> > mips64 - MIPS (64-bit big endian)
> > mips64el - MIPS (64-bit little endian)
> > mipsel - MIPS (32-bit little endian)
> > msp430 - MSP430 [experimental]
> > nvptx - NVIDIA PTX 32-bit
> > nvptx64 - NVIDIA PTX 64-bit
> > ppc32 - PowerPC 32
> > ppc32le - PowerPC 32 LE
> > ppc64 - PowerPC 64
> > ppc64le - PowerPC 64 LE
> > r600 - AMD GPUs HD2XXX-HD6XXX
> > riscv32 - 32-bit RISC-V
> > riscv64 - 64-bit RISC-V
> > sparc - Sparc
> > sparcel - Sparc LE
> > sparcv9 - Sparc V9
> > systemz - SystemZ
> > thumb - Thumb
> > thumbeb - Thumb (big endian)
> > wasm32 - WebAssembly 32-bit
> > wasm64 - WebAssembly 64-bit
> > x86 - 32-bit X86: Pentium-Pro and above
> > x86-64 - 64-bit X86: EM64T and AMD64
> > xcore - XCore
> > $ clang --print-resource-dir
> > /home/raymond/toolchain/clang-12.0.0/lib/clang/12.0.0
> > $ ls
> > /home/raymond/toolchain/clang-12.0.0/lib/clang/12.0.0/lib/linux/libclang_rt.builtins*
> > /home/raymond/toolchain/clang-12.0.0/lib/clang/12.0.0/lib/linux/libclang_rt.builtins-aarch64.a
> >
> > /home/raymond/toolchain/clang-12.0.0/lib/clang/12.0.0/lib/linux/libclang_rt.builtins-x86_64.a
> > /home/raymond/toolchain/clang-12.0.0/lib/clang/12.0.0/lib/linux/libclang_rt.builtins-armhf.a
>
> Interesting. How did you install clang/LLVM? Did you get those builins
> library from multiple release packages?
>
That is an old version 12.0.0 and I cannot recall well where I got it
and how I installed it...
But looking at the CI job here [1], the clang builds passed and that
implies it got the libs properly.
I will take a look at the newer clang releases if I can find some clues.
[1] https://github.com/u-boot/u-boot/pull/773
Regards,
Raymond
> In the OP-TEE project we used to do that via a get_clang.sh script [1] but
> it broke when llvm-project stopped releasing all the binary packages we needed
> (aarch64-linux-gnu and armv7a-linux-gnueabihf). So we ended up importing the
> __udivti3 implementation in source code instead [3]. I'm not saying this is
> the way to go, but relying on libclang_rt.builtins assumes that a proper
> toolchain is available, and that should at least be documented.
>
> [1] https://github.com/OP-TEE/build/blob/1b68e0bb8a00/get_clang.sh
> [2] https://github.com/OP-TEE/build/commit/8dd39dc99f09
> [3] https://github.com/OP-TEE/optee_os/commit/48952fd403d8
>
> Regards,
> --
> Jerome
>
> >
> > Regards,
> > Raymond
> >
> >> Thanks,
> >> --
> >> Jerome
> >>
> >>> endif
> >>> endif
> >>> +undefine MK_ARCH
> >>> PLATFORM_LIBS += $(PLATFORM_LIBGCC)
> >>>
> >>> ifdef CONFIG_CC_COVERAGE
