Issue
Problem
I am learning how to do C interop in bare metal Rust project. I have a simple C project that takes a struct and prints it. I compile it with arm-none-eabi-gcc to generate a libfoo.a and link it against my Rust project.
The Rust project is configure to use the arm gcc and linker in .cargo.config.toml. I generate bindings with bindgen and call a C function through the binding.
I am having issue with getting the project to compile. When rust tries to link against the static C library, it complains about
error: linking with `arm-none-eabi-gcc` failed: exit status: 1
|
= note: LC_ALL="C" PATH="/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/bin:/Users/yuenton/.pyenv/shims:/Applica
tions/Simplicity Studio.app/Contents/Eclipse/developer/adapter_packs/commander/Commander.app/Contents/MacOS:/usr/local/opt/ruby/bin:/usr/local/lib/ruby/gems/2.7
.0/bin:/Applications/cov-analysis-macosx-2022-3-0/bin/:/Applications/SEGGER/JLink_V760h:
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin:/Users/yuenton/.toolbox/bin:/Users/yuenton/.nvm/versions/node/v14.20.0/bin:/Users/yuenton/bin:/usr/local/b
in:/opt/homebrew/bin:/opt/homebrew/sbin:/Users/yuenton/.local/share/nvim/mason/bin:/Users/yuenton/.pyenv/bin:/Applications/Simplicity Studio.app/Contents/Eclips
e/developer/adapter_packs/commander/Commander.app/Contents/MacOS:/usr/local/opt/ruby/bin:/usr/local/lib/ruby/gems/2.7.0/bin:/Applications/SEGGER/JLink_V760h:/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-
update/bin:/Users/yuenton/.toolbox/bin:/Users/yuenton/.nvm/versions/node/v14.20.0/bin:/Users/yuenton/bin:/usr/local/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/us
r/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/
var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Users/yuen
ton/.cargo/bin:/Applications/kitty.app/Contents/MacOS:/usr/local/opt/fzf/bin" VSLANG="1033" "arm-none-eabi-gcc" "/var/folders/lm/n3lqn5fx2qsddzty2389rfgcfkmffy/
T/rustc5AOqmy/symbols.o" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/app-6d1120295b5167b4.44hpxx6ly2g0n
6p4.rcgu.o" "-Wl,--as-needed" "-L" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps" "-L" "/Volumes/workplac
e/playground/rust_embedded_with_c_interop/app/target/debug/deps" "-L" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/
debug/build/app-fca9b4a0fb47443d/out" "-L" "/usr/local/opt/arm-none-eabi-gcc/gcc/arm-none-eabi/lib" "-L" "./c_proj/build/" "-L" "/Volumes/workplace/playground/r
ust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/build/cortex-m-c1b153b4741594d3/out" "-L" "/Volumes/workplace/playground/rust_embedded_with_c_in
terop/app/target/thumbv7m-none-eabi/debug/build/cortex-m-rt-feabb8431baf6f6c/out" "-L" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/th
umbv7m-none-eabi/debug/build/cortex-m-semihosting-3928837b527a45a9/out" "-L" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-
none-eabi/lib" "-Wl,-Bstatic" "-lfoo" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libcty-580a16e85c8469
02.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libcortex_m_rt-c96c0df2d2e53803.rlib" "/Volumes/wo
rkplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libr0-c044695858752b9f.rlib" "/Volumes/workplace/playground/rust_embedd
ed_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libcortex_m-4e3d1e159a5b50d2.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/ta
rget/thumbv7m-none-eabi/debug/deps/libaligned-433f80187af623df.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/d
ebug/deps/libas_slice-7cd7b96cd776cbe0.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libstable_dere
f_trait-d6be1c622a71e64c.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libgeneric_array-2fb71faed80
7ea2c.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libgeneric_array-fe72171b4f9ffd35.rlib" "/Volum
es/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libgeneric_array-b85e7f6fe2cef964.rlib" "/Volumes/workplace/playgr
ound/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libtypenum-271c16d2a2f77c26.rlib" "/Volumes/workplace/playground/rust_embedded_with_c
_interop/app/target/thumbv7m-none-eabi/debug/deps/libpanic_halt-4d0b3983ed02fa87.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/th
umbv7m-none-eabi/debug/deps/libcortex_m_semihosting-695180d6324c8ba4.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-
eabi/debug/deps/libcortex_m-09751e7d921baf68.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libembed
ded_hal-2809cd32091c3ba8.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libvoid-fb1bf4e02014cb07.rli
b" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libnb-56a04b5218fae863.rlib" "/Volumes/workplace/playgro
und/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libnb-f9897756642f2d1b.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_inter
op/app/target/thumbv7m-none-eabi/debug/deps/libvolatile_register-6c4b892b7612085e.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/t
humbv7m-none-eabi/debug/deps/libvcell-16cd54fe2c2cf158.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/dep
s/libbare_metal-cdf719ed4a7ace5b.rlib" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-none-eabi/lib/librustc_std_workspace_c
ore-05bb5221ddab705b.rlib" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-none-eabi/lib/libcore-43d826545f9dd0d1.rlib" "/Use
rs/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-none-eabi/lib/libcompiler_builtins-c59fdfa9b274eac2.rlib" "-Wl,-Bdynamic" "-Wl,--e
h-frame-hdr" "-Wl,-z,noexecstack" "-L" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-none-eabi/lib" "-o" "/Volumes/workplac
e/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/app-6d1120295b5167b4" "-Wl,--gc-sections" "-no-pie" "-nodefaultlibs" "-Wl,-Tl
ink.x" "-nostartfiles"
= note: /usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /Volumes/workplace/playground/r
ust_embedded_with_c_interop/app/target/debug/deps/libfoo.a(foo.o): in function `print_hello_foo':
foo.c:(.text+0x4c): undefined reference to `printf'
collect2: error: ld returned 1 exit status
= note: some `extern` functions couldn't be found; some native libraries may need to be installed or have their path specified
= note: use the `-l` flag to specify native libraries to link
= note: use the `cargo:rustc-link-lib` directive to specify the native libraries to link with Cargo (see https://doc.rust-lang.org/cargo/reference/build-scrip
ts.html#cargorustc-link-libkindname)
I tried linking against libc.a provided by arm-none-eabi to get a reference to the printf definition, but it introduces more undefined references
error: linking with `arm-none-eabi-gcc` failed: exit status: 1
|
= note: LC_ALL="C" PATH="/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/bin:/Users/yuenton/.pyenv/shims:/Applica
tions/Simplicity Studio.app/Contents/Eclipse/developer/adapter_packs/commander/Commander.app/Contents/MacOS:/usr/local/opt/ruby/bin:/usr/local/lib/ruby/gems/2.7
.0/bin:/Applications/cov-analysis-macosx-2022-3-0/bin/:/Applications/SEGGER/JLink_V760h:
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin:/Users/yuenton/.toolbox/bin:/Users/yuenton/.nvm/versions/node/v14.20.0/bin:/Users/yuenton/bin:/usr/local/b
in:/opt/homebrew/bin:/opt/homebrew/sbin:/Users/yuenton/.local/share/nvim/mason/bin:/Users/yuenton/.pyenv/bin:/Applications/Simplicity Studio.app/Contents/Eclips
e/developer/adapter_packs/commander/Commander.app/Contents/MacOS:/usr/local/opt/ruby/bin:/usr/local/lib/ruby/gems/2.7.0/bin:lpay/Applications/SEGGER/JLink_V760h:/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-
update/bin:/Users/yuenton/.toolbox/bin:/Users/yuenton/.nvm/versions/node/v14.20.0/bin:/Users/yuenton/bin:/usr/local/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/us
r/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/
var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Users/yuen
ton/.cargo/bin:/Applications/kitty.app/Contents/MacOS:/usr/local/opt/fzf/bin" VSLANG="1033" "arm-none-eabi-gcc" "/var/folders/lm/n3lqn5fx2qsddzty2389rfgcfkmffy/
T/rustcjzQWtq/symbols.o" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/app-6d1120295b5167b4.44hpxx6ly2g0n
6p4.rcgu.o" "-Wl,--as-needed" "-L" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps" "-L" "/Volumes/workplac
e/playground/rust_embedded_with_c_interop/app/target/debug/deps" "-L" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/
debug/build/app-fca9b4a0fb47443d/out" "-L" "/usr/local/opt/arm-none-eabi-gcc/gcc/arm-none-eabi/lib" "-L" "./c_proj/build/" "-L" "/Volumes/workplace/playground/r
ust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/build/cortex-m-c1b153b4741594d3/out" "-L" "/Volumes/workplace/playground/rust_embedded_with_c_in
terop/app/target/thumbv7m-none-eabi/debug/build/cortex-m-rt-feabb8431baf6f6c/out" "-L" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/th
umbv7m-none-eabi/debug/build/cortex-m-semihosting-3928837b527a45a9/out" "-L" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-
none-eabi/lib" "-Wl,-Bstatic" "-lfoo" "-lc" "-lc_nano" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libc
ty-580a16e85c846902.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libcortex_m_rt-c96c0df2d2e53803.r
lib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libr0-c044695858752b9f.rlib" "/Volumes/workplace/playg
round/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libcortex_m-4e3d1e159a5b50d2.rlib" "/Volumes/workplace/playground/rust_embedded_with
_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libaligned-433f80187af623df.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thu
mbv7m-none-eabi/debug/deps/libas_slice-7cd7b96cd776cbe0.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/de
ps/libstable_deref_trait-d6be1c622a71e64c.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libgeneric_
array-2fb71faed807ea2c.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libgeneric_array-fe72171b4f9ff
d35.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libgeneric_array-b85e7f6fe2cef964.rlib" "/Volumes
/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libtypenum-271c16d2a2f77c26.rlib" "/Volumes/workplace/playground/rus
t_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libpanic_halt-4d0b3983ed02fa87.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_inte
rop/app/target/thumbv7m-none-eabi/debug/deps/libcortex_m_semihosting-695180d6324c8ba4.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/targ
et/thumbv7m-none-eabi/debug/deps/libcortex_m-09751e7d921baf68.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/de
bug/deps/libembedded_hal-2809cd32091c3ba8.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libvoid-fb1
bf4e02014cb07.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libnb-56a04b5218fae863.rlib" "/Volumes/
workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libnb-f9897756642f2d1b.rlib" "/Volumes/workplace/playground/rust_embe
dded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/libvolatile_register-6c4b892b7612085e.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_int
erop/app/target/thumbv7m-none-eabi/debug/deps/libvcell-16cd54fe2c2cf158.rlib" "/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-no
ne-eabi/debug/deps/libbare_metal-cdf719ed4a7ace5b.rlib" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-none-eabi/lib/librust
c_std_workspace_core-05bb5221ddab705b.rlib" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-none-eabi/lib/libcore-43d826545f9
dd0d1.rlib" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-none-eabi/lib/libcompiler_builtins-c59fdfa9b274eac2.rlib" "-Wl,-B
dynamic" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "/Users/yuenton/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/thumbv7m-none-eabi/lib" "-o" "
/Volumes/workplace/playground/rust_embedded_with_c_interop/app/target/thumbv7m-none-eabi/debug/deps/app-6d1120295b5167b4" "-Wl,--gc-sections" "-no-pie" "-nodefa
ultlibs" "-Wl,-Tlink.x" "-nostartfiles"
= note: /usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-sbrkr.o): in function `_sbrk_r':
sbrkr.c:(.text._sbrk_r+0x18): undefined reference to `_sbrk'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-writer.o): in function `_write_r':
writer.c:(.text._write_r+0x24): undefined reference to `_write'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-closer.o): in function `_close_r':
closer.c:(.text._close_r+0x18): undefined reference to `_close'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-fstatr.o): in function `_fstat_r':
fstatr.c:(.text._fstat_r+0x1c): undefined reference to `_fstat'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-isattyr.o): in function `_isatty_r':
isattyr.c:(.text._isatty_r+0x18): undefined reference to `_isatty'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-lseekr.o): in function `_lseek_r':
lseekr.c:(.text._lseek_r+0x24): undefined reference to `_lseek'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-readr.o): in function `_read_r':
readr.c:(.text._read_r+0x24): undefined reference to `_read'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-abort.o): in function `abort':
abort.c:(.text.abort+0x10): undefined reference to `_exit'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-signalr.o): in function `_kill_r':
signalr.c:(.text._kill_r+0x1c): undefined reference to `_kill'
/usr/local/opt/gcc-arm-none-eabi-8-2019-q3-update/bin/../lib/gcc/arm-none-eabi/8.3.1/../../../../arm-none-eabi/bin/ld: /usr/local/opt/arm-none-eabi-gc
c/gcc/arm-none-eabi/lib/libc.a(lib_a-signalr.o): in function `_getpid_r':
signalr.c:(.text._getpid_r+0x4): undefined reference to `_getpid'
collect2: error: ld returned 1 exit status
= note: some `extern` functions couldn't be found; some native libraries may need to be installed or have their path specified
= note: use the `-l` flag to specify native libraries to link
= note: use the `cargo:rustc-link-lib` directive to specify the native libraries to link with Cargo (see https://doc.rust-lang.org/cargo/reference/build-scrip
ts.html#cargorustc-link-libkindname)
I would expect that glib functions definition is automatically linked by the compiler and I shouldn't have to provided the libraries. Am I missing a step when setting up the C static library?
I'm confused how the native library is supposed to be linked when cross compiling with Rust for C libraries. Any help is greatly appreciated!
Project Setup
This is my C files
// foo.h
typedef struct {
int x;
float y;
char str[20];
} foo_s;
void print_hello_foo(const foo_s *foo);
// foo.c
#include "include/foo.h"
#include <stdio.h>
void print_hello_foo(const foo_s *foo) {
printf("foo says hello, x: %i, y: %f, str: %s\n", foo->x, foo->y, foo->str);
}
I have a cmake project that compiles it
// CMakeLists.txt
cmake_minimum_required(VERSION 3.23)
set(CMAKE_C_COMPILER_FORCED TRUE)
set(CMAKE_CXX_COMPILER_FORCED TRUE)
project(foo)
add_library(foo foo.c)
target_include_directories(foo PUBLIC include)
message(styuen "$(CMAKE_INSTALL_INCLUDEDIR)")
install(TARGETS foo PUBLIC_HEADER DESTINATION $(CMAKE_INSTALL_INCLUDEDIR)/foo)
// toolchain.cmake
set(CMAKE_SYSTEM_NAME Generic CACHE STRING "The operating system to target. Generic for cross-platform" FORCE)
set(CMAKE_SYSTEM_PROCESSOR arm CACHE STRING "The target CPU architecture" FORCE)
set(CMAKE_CROSSCOMPILING 1 CACHE STRING "" FORCE)
set(TOOLCHAIN_PREFIX arm-none-eabi-)
find_program(BINUTILS_PATH ${TOOLCHAIN_PREFIX}gcc NO_CACHE)
if (NOT BINUTILS_PATH)
message(FATAL_ERROR "ARM GCC toolchain not found")
endif ()
get_filename_component(ARM_TOOLCHAIN_DIR ${BINUTILS_PATH} DIRECTORY)
# Without that flag CMake is not able to pass test compilation check
if (${CMAKE_VERSION} VERSION_EQUAL "3.6.0" OR ${CMAKE_VERSION} VERSION_GREATER "3.6")
set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
else ()
set(CMAKE_EXE_LINKER_FLAGS_INIT "--specs=nosys.specs")
endif ()
set(CMAKE_C_COMPILER ${TOOLCHAIN_PREFIX}gcc CACHE STRING "" FORCE)
set(CMAKE_ASM_COMPILER ${CMAKE_C_COMPILER} CACHE STRING "" FORCE)
set(CMAKE_CXX_COMPILER ${TOOLCHAIN_PREFIX}g++ CACHE STRING "" FORCE)
set(CMAKE_AR ${TOOLCHAIN_PREFIX}gcc-ar CACHE STRING "" FORCE)
set(CMAKE_RANLIB ${TOOLCHAIN_PREFIX}gcc-ranlib CACHE STRING "" FORCE)
set(CMAKE_LINKER ${TOOLCHAIN_PREFIX}/arm-none-eabi-ld CACHE STRING "" FORCE)
execute_process(COMMAND ${CMAKE_C_COMPILER} -print-sysroot
OUTPUT_VARIABLE ARM_GCC_SYSROOT OUTPUT_STRIP_TRAILING_WHITESPACE)
In my rust project I the following for build configuration
# .cargo/config.toml
[target.thumbv7m-none-eabi]
# uncomment this to make `cargo run` execute programs on QEMU
runner = "qemu-system-arm -cpu cortex-m3 -machine lm3s6965evb -nographic -semihosting-config enable=on,target=native -kernel"
[target.'cfg(all(target_arch = "arm", target_os = "none"))']
# uncomment ONE of these three option to make `cargo run` start a GDB session
# which option to pick depends on your system
runner = "arm-none-eabi-gdb -q -x openocd.gdb"
# runner = "gdb-multiarch -q -x openocd.gdb"
# runner = "gdb -q -x openocd.gdb"
rustflags = [
# Previously, the linker arguments --nmagic and -Tlink.x were set here.
# They are now set by build.rs instead. The linker argument can still
# only be set here, if a custom linker is needed.
# By default, the LLD linker is used, which is shipped with the Rust
# toolchain. If you run into problems with LLD, you can switch to the
# GNU linker by uncommenting this line:
"-C", "linker=arm-none-eabi-ld",
# If you need to link to pre-compiled C libraries provided by a C toolchain
# use GCC as the linker by uncommenting the three lines below:
"-C", "linker=arm-none-eabi-gcc",
"-C", "link-arg=-Wl,-Tlink.x",
"-C", "link-arg=-nostartfiles",
]
[build]
# Pick ONE of these default compilation targets
# target = "thumbv6m-none-eabi" # Cortex-M0 and Cortex-M0+
target = "thumbv7m-none-eabi" # Cortex-M3
# target = "thumbv7em-none-eabi" # Cortex-M4 and Cortex-M7 (no FPU)
# target = "thumbv7em-none-eabihf" # Cortex-M4F and Cortex-M7F (with FPU)
# target = "thumbv8m.base-none-eabi" # Cortex-M23
# target = "thumbv8m.main-none-eabi" # Cortex-M33 (no FPU)
# target = "thumbv8m.main-none-eabihf" # Cortex-M33 (with FPU)
// build.rs
//! This build script copies the `memory.x` file from the crate root into
//! a directory where the linker can always find it at build time.
//! For many projects this is optional, as the linker always searches the
//! project root directory -- wherever `Cargo.toml` is. However, if you
//! are using a workspace or have a more complicated build setup, this
//! build script becomes required. Additionally, by requesting that
//! Cargo re-run the build script whenever `memory.x` is changed,
//! updating `memory.x` ensures a rebuild of the application with the
//! new memory settings.
//!
//! The build script also sets the linker flags to tell it which link script to use.
use cmake::Config;
use std::env;
use std::fs::File;
use std::io::Write;
use std::path::PathBuf;
fn main() {
// Put `memory.x` in our output directory and ensure it's
// on the linker search path.
let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
File::create(out.join("memory.x"))
.unwrap()
.write_all(include_bytes!("memory.x"))
.unwrap();
println!("cargo:rustc-link-search={}", out.display());
// By default, Cargo will re-run a build script whenever
// any file in the project changes. By specifying `memory.x`
// here, we ensure the build script is only re-run when
// `memory.x` is changed.
println!("cargo:rerun-if-changed=memory.x");
println!(
"cargo:rustc-link-search=native=/usr/local/opt/arm-none-eabi-gcc/gcc/arm-none-eabi/lib"
);
println!("cargo:rustc-link-search=native=./c_proj/build/");
println!("cargo:rustc-link-lib=static=foo");
// println!("cargo:rustc-link-lib=static=c");
println!("cargo:rerun-if-changed=c_proj/include/foo.h");
println!("cargo:rerun-if-changed=c_proj/foo.c");
let bindings = bindgen::Builder::default()
.header("c_proj/include/foo.h")
.use_core()
.ctypes_prefix("cty")
.parse_callbacks(Box::new(bindgen::CargoCallbacks))
.generate()
.expect("Unable to generate bindings");
let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
bindings
.write_to_file(out_path.join("bindings.rs"))
.expect("Couldn't write bindings!");
}
rust main.rs
#![no_std]
#![no_main]
#![allow(non_upper_case_globals)]
#![allow(non_camel_case_types)]
#![allow(non_snake_case)]
include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
use cortex_m_semihosting::{debug, hprintln};
// pick a panicking behavior
use panic_halt as _; // you can put a breakpoint on `rust_begin_unwind` to catch panics
// use panic_abort as _; // requires nightly
// use panic_itm as _; // logs messages over ITM; requires ITM support
// use panic_semihosting as _; // logs messages to the host stderr; requires a debugger
use cortex_m::asm;
use cortex_m_rt::entry;
#[entry]
fn main() -> ! {
hprintln!("Hello, world!");
let foo = foo_s {
x: 3,
y: 3.14,
str_: [
116, 101, 115, 116, 105, 110, 103, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
],
};
unsafe {
print_hello_foo(&foo);
}
// exit QEMU
// NOTE do not run this on hardware; it can corrupt OpenOCD state
debug::exit(debug::EXIT_SUCCESS);
loop {
// your code goes here
}
}
Solution
The library has platform dependencies that must be resolved by a platform specific porting layer that you need to provide. This is necessary because I/O and memory management are platform dependent.
For the Newlib C library that arm-none-eabi-gcc normally uses this is the "syscalls" layer.
Most syscalls can be implemented as non-functioning stubs. If you only need to support printf then implementing write for stdout is sufficient.
If you use dynamic memory allocation also sbrk.
If your application is multithreaded, then you should implement the re-entrant versions suffixed _r.
Minimal implementations of these stubs are provided in the documentation. All you need do for example is create a C source syscalls.c, containing these stubs then compile and link it to your project. Some will need re-implementation to be functional, but that will allow your code to link.
In response to Carl Norum's comment, internally parts of newlib use dynamic allocation. That might be a good reason to override printf() with a third-party "lightweight" implementation. To ensure it is supported you will need to have at least a small heap. Often the linker script will create a heap space (typically all space available after static allocation), that being the case then the following sbrk implementation will provide a heap:
register char *stack_ptr asm("sp");
void *_sbrk(ptrdiff_t incr)
{
extern char end asm("end"); // Defined by the linker.
static char *heap_end;
char *prev_heap_end;
if (heap_end == NULL)
heap_end = &end;
prev_heap_end = heap_end;
if (heap_end + incr > stack_ptr)
{
errno = ENOMEM;
return (void *)-1;
}
heap_end += incr;
return (void *)prev_heap_end;
}
_sbrk_r() if needed (multi-threaded code) would have a thread-local errno (or just do not rely on errno to be correct). Moreover in a multi-threaded environment you would need to override __malloc_lock() and __malloc_unlock() stubs to make dynamic memory allocation thread-safe.
Answered By - Clifford Answer Checked By - Cary Denson (WPSolving Admin)