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
Regards,
Raymond
> Thanks,
> --
> Jerome
>
> > endif
> > endif
> > +undefine MK_ARCH
> > PLATFORM_LIBS += $(PLATFORM_LIBGCC)
> >
> > ifdef CONFIG_CC_COVERAGE
