RPI Pico子项目构建失败：ld.exe提示二进制信息需在前256字节

错误日志 #

[build] Starting build
[proc] Executing command: "C:\Program Files\Raspberry Pi\Pico SDK v1.5.1\cmake\bin\cmake.EXE" --build d:/_svn/compass/AVR/AMPER_BATERIA_PICO/build --config Debug --target all --
[build] [1/2  50% :: 0.133] Building C object GENET_CORE_PICO/CMakeFiles/GENET_CORE.dir/GENet_Core.c.obj
[build] [2/2 100% :: 0.293] Linking CXX executable Amper_Bateria.elf
[build] FAILED: Amper_Bateria.elf 
[...a lot of build output here...]    
[build] C:/Program Files/Raspberry Pi/Pico SDK v1.5.1/pico-sdk/src/rp2_common/hardware_base/include/hardware/address_mapped.h:122: multiple definition of `adc_init'; GENET_CORE_PICO/CMakeFiles/GENET_CORE.dir/C_/Program_Files/Raspberry_Pi/Pico_SDK_v1.5.1/pico-sdk/src/rp2_common/hardware_adc/adc.c.obj:C:/Program Files/Raspberry Pi/Pico SDK v1.5.1/pico-sdk/src/rp2_common/hardware_base/include/hardware/address_mapped.h:122: first defined here
[proc] The command: "C:\Program Files\Raspberry Pi\Pico SDK v1.5.1\cmake\bin\cmake.EXE" --build d:/_svn/compass/AVR/AMPER_BATERIA_PICO/build --config Debug --target all -- exited with code: 1
[build] c:/progra~2/gnuarm~1/102021~1.10/bin/../lib/gcc/arm-none-eabi/10.3.1/../../../../arm-none-eabi/bin/ld.exe: Binary info must be in first 256 bytes of the binary
[build] collect2.exe: error: ld returned 1 exit status
[build] ninja: build stopped: subcommand failed.
[driver] Build completed: 00:00:00.569
[build] Build finished with exit code 1

主项目CMakeLists.txt代码 #

cmake_minimum_required(VERSION 3.13)
include(pico_sdk_import.cmake)
project(Amper_Bateria C CXX ASM)
set(srcDir D:/_svn/compass/AVR/AMPER_BATERIA_PICO)
add_subdirectory(GENET_CORE_PICO)
pico_sdk_init()
set(SOURCES userland.c userland.h)
add_executable(Amper_Bateria ${SOURCES})
target_link_directories(Amper_Bateria PRIVATE ${coreDir})
pico_add_extra_outputs(Amper_Bateria)
target_include_directories(Amper_Bateria PRIVATE GENET_CORE_PICO)
target_link_directories(Amper_Bateria PRIVATE GENET_CORE_PICO)
target_link_libraries(Amper_Bateria PRIVATE GENET_CORE pico_stdlib hardware_adc pico_multicore hardware_timer)

子项目GENET_CORE_PICO/CMakeLists.txt代码 #

cmake_minimum_required(VERSION 3.13)
include(pico_sdk_import.cmake)
project(GENET_CORE C CXX ASM)
pico_sdk_init()
add_library(GENET_CORE 
OBJECT GENet_Core.c GENet_Core.h GENet_ISR_LIB.c GENet_ISR_LIB.h ds18b20_TIMER_DRIVER.c ds18b20_TIMER_DRIVER.h crc8_16.c checksum.h
)
target_link_libraries(GENET_CORE pico_stdlib hardware_adc)

问题原因 #

1. Pico SDK重复初始化：主项目和子项目都调用了pico_sdk_init()，导致SDK的硬件组件（比如hardware_adc）被多次链接，出现符号重复定义（如adc_init）。
2. OBJECT库的依赖管理不当：子项目的OBJECT库直接链接了hardware_adc等SDK组件，主项目再次链接这些组件时，就会重复引入相同的符号。
3. 冗余的链接配置：主项目中的target_link_directories属于冗余配置，CMake通过target_link_libraries链接库时会自动处理路径，无需手动指定。

修复方案 #

修改主项目CMakeLists.txt #

只在主项目中初始化SDK，清理冗余配置，统一管理所有依赖：

cmake_minimum_required(VERSION 3.13)
include(pico_sdk_import.cmake)
project(Amper_Bateria C CXX ASM)

# 仅在主项目初始化Pico SDK
pico_sdk_init()

add_subdirectory(GENET_CORE_PICO)

set(SOURCES userland.c userland.h)
add_executable(Amper_Bateria ${SOURCES})

pico_add_extra_outputs(Amper_Bateria)
target_include_directories(Amper_Bateria PRIVATE GENET_CORE_PICO)
# 统一链接子项目库和所有SDK依赖
target_link_libraries(Amper_Bateria PRIVATE 
    GENET_CORE 
    pico_stdlib 
    hardware_adc 
    pico_multicore 
    hardware_timer
)

修改子项目CMakeLists.txt #

移除重复的SDK初始化，OBJECT库仅管理自身源码，依赖通过主项目传递：

cmake_minimum_required(VERSION 3.13)
project(GENET_CORE C CXX ASM)

# 构建OBJECT库，只包含自身源码
add_library(GENET_CORE 
OBJECT 
    GENet_Core.c GENet_Core.h 
    GENet_ISR_LIB.c GENet_ISR_LIB.h 
    ds18b20_TIMER_DRIVER.c ds18b20_TIMER_DRIVER.h 
    crc8_16.c checksum.h
)

# 仅添加SDK头文件依赖，或通过PRIVATE传递依赖给主项目
target_link_libraries(GENET_CORE PRIVATE pico_stdlib hardware_adc)

说明 #

修改后，SDK只会被初始化一次，所有依赖由主项目统一管理，避免了符号重复定义的问题。OBJECT库的依赖会通过CMake的依赖传递机制正确传递给主项目，不会出现重复链接的情况。

内容的提问来源于stack exchange，提问作者bajtec