linker - AVR链接器错误 "relocation truncated to fit"

Question

我正在尝试为ATmega328 micro编译一些代码，并且我想使用Arduino的库和核心。我正在使用CMake。我已经编译了核心库和代码的所有对象以及Arduino的库。但是，当链接时，它们向我显示以下错误。

..."relocation truncated to fit: R_AVR_13_PCREL against symbol"..."avr5/libgcc.a"...

我有 found through Google，这是一个常见错误，但是没有解决方案对我有用。我唯一不能做的就是在链接器语句的末尾添加“-lm”和“-lc”标志，因为我不知道如何使用CMake做到这一点。

编辑:我也尝试使用makefile进行编译，但是得到了相同的结果，甚至在链接器语句的末尾放置了“-lm”和“-lc”标志。

我将我的Makefile和CMake文件放在这里:

CMakeList.txt 主要CMake文件

cmake_minimum_required(VERSION 2.6)
Project(IMU)

set(ARDUINO_PROCESSOR atmega328p)
set(ARDUINO_PROCESSOR_FREQ 1600000L)

include(./arduino.cmake)

add_library(ardlib
        libraries/EEPROM/EEPROM.cpp
        libraries/Wire/utility/twi.c
        libraries/Wire/Wire.cpp
        libraries/HMC58X3/HMC58X3
        )

LINK_DIRECTORIES(${IMU_SRC_DIR}/libarduinocore
        ${IMU_SRC_DIR}/libraries/EEPROM
        ${IMU_SRC_DIR}/libraries/Wire
        ${IMU_SRC_DIR}/libraries/HMC58X3
        )

link_libraries(arduinocore ardlib)

include_directories(
        libarduinocore
        libraries/EEPROM
        libraries/Wire
        libraries/Wire/utility
        libraries/HMC58X3
        )

set(C_SRCS
        ADXL345.cpp
        ApplicationRoutines.cpp
        DCM.cpp
        HMC5883L.cpp
        ITG3200.cpp
        matrix.cpp
        output.cpp
        timing.cpp
        vector.cpp
        )

set(C_HDRS
        ADXL345.h
        ApplicationRoutines.h
        DCM.h
        HMC5883L.h
        ITG3200.h
        matrix.h
        output.h
        timing.h
        vector.h
        declarations.h
        )

add_executable(IMU.elf main.cpp ${C_SRCS} ${C_HDRS})

add_subdirectory(libarduinocore)

arduino.cmake 。那是由CMakeList.txt导入的:

set(ARDUINO_PROCESSOR atmega328p)
set(ARDUINO_PROCESSOR_FREQ 16000000L)

# This module defines macros intended for use by cross-compiling toolchain files when
# CMake is not able to automatically detect the compiler identification.
include (CMakeForceCompiler)

# Set this for cross compiling.  Otherwise it is set to CMAKE_HOST_SYSTEM_NAME,
# which is the system we are developing on.
set (CMAKE_SYSTEM_NAME Generic)

# It sets CMAKE_<lang>_COMPILER to the given compiler and the cmake internal variable
# CMAKE_<lang>_COMPILER_ID to the given compiler-id. It also bypasses the check for
# working compiler and basic compiler information tests.
SET(CMAKE_C_COMPILER avr-gcc)
SET(CMAKE_CXX_COMPILER avr-g++)
cmake_force_cxx_compiler (avr-g++ CrossAVR)
cmake_force_c_compiler (avr-gcc CrossAVR)

# Appparently we want to use the gnuc99 standard.
#set (CSTANDARD "-std=gnu99")

# Generate .stabs debugging symbols for assembler source lines. This enables avr-gdb to
# trace through assembler source files.
#set (CDEBUG "-gstabs")

# Warn for functions declared or defined without specified argument types.
set (CWARN "-Wall -Wstrict-prototypes")

# -funsigned-char - Make any unqualfied char type an unsigned char. Without this option,
#   they default to a signed char.
# -funsigned-bitfields - Make any unqualified bitfield type unsigned. By default,
#    they are signed.
# -fpack-struct - Pack all structure members together without holes.
# -fshort-enums - Allocate to an enum type only as many bytes as it needs for the declared
#   range of possible values. Specifically, the enum type will be equivalent to the
#   smallest integer type which has enough room.
set (CTUNING_FLAGS "-ffunction-sections -fdata-sections -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums")

# Optimize for size.   The special option -Os is meant to turn on all -O2 optimizations
# that are not expected to increase code size.
set (COPT "-Os")

SET(CINCS "-I${ArduinoCode_SOURCE_DIR}/libarduinocore")

# Finally the compilation flags are now configured.
set(CMAKE_CXX_FLAGS "-lc -lm -mmcu=${ARDUINO_PROCESSOR} -DF_CPU=${ARDUINO_PROCESSOR_FREQ} ${CTUNING_FLAGS} ${CWARN} ${CSTANDARD} ${CDEBUG} ${COPT} ${CINCS} -lc")
set(CMAKE_C_FLAGS "-lc -lm ${CMAKE_CXX_FLAGS} ${CTUNING_FLAGS} ${CWARN} ${CSTANDARD} ${CDEBUG} ${CINCS} -lc")

# On gentoo, -rdynamic is passed to the compiler. The avr compiler does not recognize this
# option.  Also, we are not building shared libraries.
set(CMAKE_EXE_LINKER_FLAGS "-Wl,--gc-sections")
set(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS ""

Arduino核心CMake文件。这是放置在 libarduinocore目录中的CMakeList.txt文件。

include(../arduino.cmake)


add_library (arduinocore
        HardwareSerial.cpp
        pins_arduino.c
        Print.cpp
        Tone.cpp
        WInterrupts.c
        wiring_analog.c
        wiring.c
        wiring_digital.c
        wiring_pulse.c
        wiring_shift.c
        WMath.cpp
        WString.cpp
        )

Makefile

TARGET = IMU
PORT = /dev/ttyACM0
BAUD = 57600
PROGRAMMER = arduino
MCU = atmega328p
F_CPU = 8000000L

CXX_SRCS = ADXL345.cpp \
           ApplicationRoutines.cpp \
           DCM.cpp \
           HMC5883L.cpp \
           ITG3200.cpp \
           matrix.cpp \
           output.cpp \
           timing.cpp \
           vector.cpp

CXX_OBJ = $(CXX_SRCS:.cpp=.o)

CXX_HDRS = ADXL345.h \
           ApplicationRoutines.h \
           DCM.h \
           declarations.h \
           HMC5883L.h \
           ITG3200.h \
           matrix.h \
           output.h \
           timing.h \
           vector.h

CORE_DIR = libarduinocore

CORE_CXX_SRCS = $(CORE_DIR)/HardwareSerial.cpp \
                $(CORE_DIR)/Print.cpp \
                $(CORE_DIR)/Tone.cpp \
                $(CORE_DIR)/WMath.cpp \
                $(CORE_DIR)/WString.cpp

CORE_CXX_OBJ = $(CORE_CXX_SRCS:.cpp=.o)                                                                                                                                                                        

CORE_CC_SRCS = $(CORE_DIR)/pins_arduino.c \                                                                                                                                                                    
               $(CORE_DIR)/WInterrupts.c \                                                                                                                                                                     
               $(CORE_DIR)/wiring_analog.c \                                                                                                                                                                   
               $(CORE_DIR)/wiring.c \                                                                                                                                                                          
               $(CORE_DIR)/wiring_digital.c \                                                                                                                                                                  
               $(CORE_DIR)/wiring_pulse.c \                                                                                                                                                                    
               $(CORE_DIR)/wiring_shift.c                                                                                                                                                                      

CORE_CC_OBJ = $(CORE_CC_SRCS:.c=.o)                                                                                                                                                                            

CORE_HDRS = $(CORE_DIR)/binary.h \                                                                                                                                                                             
            $(CORE_DIR)/HardwareSerial.h \                                                                                                                                                                     
            $(CORE_DIR)/pins_arduino.h \                                                                                                                                                                       
            $(CORE_DIR)/Print.h \                                                                                                                                                                              
            $(CORE_DIR)/Stream.h \                                                                                                                                                                             
            $(CORE_DIR)/WCharacter.h \                                                                                                                                                                         
            $(CORE_DIR)/WConstants.h \                                                                                                                                                                         
            $(CORE_DIR)/wiring.h \                                                                                                                                                                             
            $(CORE_DIR)/wiring_private.h \                                                                                                                                                                     
            $(CORE_DIR)/WProgram.h \                                                                                                                                                                           
            $(CORE_DIR)/WString.h

ARD_LIB_DIR = libraries

ARD_LIB_CXX_SRCS = $(ARD_LIB_DIR)/EEPROM/EEPROM.cpp \
                   $(ARD_LIB_DIR)/Wire/Wire.cpp \
                   $(ARD_LIB_DIR)/HMC58X3/HMC58X3.cpp
ARD_LIB_CC_SRCS = $(ARD_LIB_DIR)/Wire/utility/twi.c

ARD_LIB_CXX_OBJ = $(ARD_LIB_CXX_SRCS:.cpp=.o)
ARD_LIB_CC_OBJ = $(ARD_LIB_CC_SRCS:.c=.o)

CC = avr-gcc
CXX = avr-g++
OBJCOPY = avr-objcopy
OBJDUMP = avr-objdump
AR  = avr-ar
SIZE = avr-size
NM = avr-nm
AVRDUDE = avrdude

ARD_LIB_INC = -I$(ARD_LIB_DIR) -I$(ARD_LIB_DIR)/EEPROM -I$(ARD_LIB_DIR)/Wire -I$(ARD_LIB_DIR)/HMC58X3 -I$(ARD_LIB_DIR)/Wire/utility

FLAGS_WARN = -Wall -Wstrict-prototypes
FLAGS_TUNING = -ffunction-sections -fdata-sections -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
FLAGS_OPT = -Os

ALL_INC = -I. $(ARD_LIB_INC) -I$(CORE_DIR)
OBJS = $(CXX_OBJ) $(CORE_CXX_OBJ) $(CORE_CC_OBJ) $(ARD_LIB_CC_OBJ) $(ARD_LIB_CXX_OBJ)
ALL_OBJS := $(addprefix build/, $(notdir $(OBJS)))
ALL_CFLAGS = -mmcu=$(MCU) -DF_CPU=$(F_CPU) $(ALL_INC) $(FLAGS_WARN) $(FLAGS_TUNNIG) $(FLAGS_OPT)
ALL_CXXFLAGS = -mmcu=$(MCU) -DF_CPU=$(F_CPU) $(ALL_INC) -Wall $(FLAGS_TUNNIG) $(FLAGS_OPT)
#ALL_ASFLAGS = -mmcu=$(MCU) -I. -x assembler-with-cpp $(ASFLAGS)

all : $(TARGET).hex
        avr-objcopy -O ihex -R .eeprom $(TARGET).out $(TARGET).hex

$(TARGET).out : $(OBJS)
        $(CXX) $(ALL_CXXFLAGS) main.cpp $(ALL_OBJS) -o $(TARGET).out -lc -lm

upload : $(TARGET).hex
        avrdude -c$(PROGRAMMER) -p$(MCU) -P$(PORT) -U flash:w:$(TARGET).hex

serialmon :
        picocom -b$(BAUD) $(PORT)

.SUFFIXES: .hex .cpp .o .c

# Compile: create object files from C++ source files.
.cpp.o:
        $(CXX) -c $(ALL_CXXFLAGS) $< -o $(addprefix build/, $(notdir $@)) -lc -lm

# Compile: create object files from C source files.
.c.o:
        $(CC) -c $(ALL_CFLAGS) $< -o $(addprefix build/, $(notdir $@)) -lc -lm


# Compile: create assembler files from C source files.
.c.s:
        $(CC) -S $(ALL_CFLAGS) $< -o build/$@ -lc -lm

Answer 1

解释:

正如错误消息所暗示的那样，问题与(代码的)重定位有关，该重定位会导致某些截断的发生。该消息来自链接器，该链接器正在尝试将代码段映射到程序存储器中的适当位置。

当将代码放置或移动到某个位置(“重定位”)并且通过JMP或CALL(即函数调用)从另一段代码引用该代码时，必须将重定位的地址添加到JMP或CALL指令中引用它。

AVR设备支持两种跳转/调用指令:JMP与RJMP以及CALL与RCALL。 R变体相对于当前位置进行调用，并且在程序存储器的使用和执行时间上均更加有效。但是，这需要付出一定的代价:RJMP和RCALL仅可用于距离其在程序存储器中位置+/- 4kb范围内的地址。对于程序存储器不超过8kb的设备，这绝不是问题，因为可以通过RCALL或RJMP从任何位置寻址整个8kb范围。

但是，在程序存储器超过8kb的设备上，并非在所有可能的位置上都如此。因此，如果链接器决定可以将要调用的代码放在RJMP/RCALL的+/- 4kb范围内，则不会有问题，但是如果链接器无法(重新)定位该代码在该范围内，RJMP/RCALL不能用于到达代码的新地址，因此地址被截断了(就像在C语言中执行uint16_t value = 12345; uint8_t truncatedValue = value;时一样)，并且生成的代码中断了。

请注意，这可能会或可能不会在任何时候超过程序存储器4kb的任何给定项目(在程序存储器> 8kb的设备上)发生，因为这取决于所需代码的重定位，这可能基本上随着每行的新行而改变。添加或删除C代码，添加要链接的每个库，甚至链接库或其他代码段的顺序(例如，当链接器找到代码时，从“A”到“B”的调用都可以工作)像“ABC”一样，但是当链接器决定像“ACB”那样重新定位时失败。

解决方案:

您必须让编译器知道它需要生成JMP/CALL指令，而不是(更有效的)RJMP/RCALL指令。在AVR Studio/Atmel Studio中，这可以通过项目的属性，工具链，AVR/GNU C编译器，优化来完成。相关选项是“在> 8k设备(-mshort-calls)上使用rjmp/rcall(有限范围)” ，需要将其设置为，未选中以防止命名错误。
如标签所示，相关的命令行选项是-mshort-calls，当从IDE外部调用gcc时，需要将其从gcc命令行参数列表中删除以实现相同的功能。

更新:

为避免不必要的困惑，此错误可能会导致Avr-gcc 4.7 中不赞成使用-mshort-calls，并将其从4.8中删除。资料来源:GCC 4.8 Changes。

用户现在应该改为使用-mrelax生成二进制文件，这些二进制文件在可能的情况下具有调用优化功能，但绝不会产生错误。