linking error when using sprintf()

Question

on my cortex-m3, i am trying to output a float variable to my UART port.. so i need to convert the float DATA into a char outputstr[].

For this purpose, i used sprintf from the libc.a

if i comment out the sprintf(), i can compile and link.
if i use sprintf(outputstr, "t"), i can compile and link.
if i use sprintf(outputstr, "The value is %f", DATA), i will get linking errors like: no memory region specified for loadable section `.rodata', '.bss', '.text', '.data'

But i had already added *(.rodata), *(.bss) etc... in my linker script as below:

...
OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")
OUTPUT_ARCH(arm)
ENTRY(reset_handler)

MEMORY {
   ROM : ORIGIN = 0x08000000, LENGTH = 128K
   RAM : ORIGIN = 0x20000000, LENGTH = 16K
}

SECTIONS {

    .ROMdata 0x8000000: AT(0x8000000){
    startup.o(.romvect)
    . = ALIGN(0x4);
    system_stm32l1xx.o(.rodata*)
    *(.rodata*)
    _ROMdataend_ = ALIGN(0x4);
    }

    .ROMstartup (_ROMdataend_): AT(_ROMdataend_){
    startup.o(.startup)
    lowlevelinit.o(.lowlevelinit .tempexchandler)
    system_stm32l1xx.o(.text*)
    . = ALIGN(0x4);
    }

    .RAMbss 0x20000000 (NOLOAD):{

    lowlevelinit.o(.ramvectortable)
    . = ALIGN(0x4);
    _RAMbssstart_ = .;
    startup.o(.stack .heap)
    . = ALIGN(0x4);
    sensor_MTH01.o(.bss*)
    . = ALIGN(0x4);
    comm_BT-HC-05.o(.bss)
    tim6.o(.bss)
    main.o(.bss)
    system_stm32l1xx.o(.bss*)
    *(.bss*)
    _RAMbssend_ = ALIGN(0x4);
    }

    .RAMcode (_RAMbssend_): AT(LOADADDR(.ROMstartup)+SIZEOF(.ROMstartup)){
    _RAMcodeVMAstart_ = .;
    _RAMcodeLMAstart_ = LOADADDR(.RAMcode);
    main.o(.ramcode .text)
    tim6.o(.tim6isr)
    tim6.o(.text)
    sensor_MTH01.o(.text)
    comm_BT-HC-05.o(.text)
    exti0_isr.o(.exti0isr)
    *(.text*)
    KEEP (*(.eh_*))
    _RAMcodeVMAend_ = ALIGN(0x4);
    }

    .RAMdata (_RAMcodeVMAend_): AT(LOADADDR(.RAMcode)+SIZEOF(.RAMcode)){
    _RAMcodeLMAend_ = (LOADADDR(.RAMcode)+SIZEOF(.RAMcode));
    _RAMdataVMAstart_ = .;
    _RAMdataLMAstart_ = LOADADDR(.RAMdata);
    sensor_MTH01.o(.data)
    system_stm32l1xx.o(.data*)
    *(.data*)
    _RAMdataVMAend_ = ALIGN(0x4);
    _RAMdataLMAend_ = LOADADDR(.RAMdata) + SIZEOF(.RAMdata);
    }


}
...

Also, i did include the lib paths and include paths in my makefile as below:

On a side note, i am also using strlen() and other float division operations from the libc.a and libgcc.a and these functions complile, link and work ok.

    ...
    CC = arm-none-eabi-gcc
    AS = arm-none-eabi-as
    LD = arm-none-eabi-ld
    OBJCPY = arm-none-eabi-objcopy

    CCFLAGS = -c -mcpu=cortex-m3 -mthumb -O0 -g -Wall
    ASMFLAGS = -mcpu=cortex-m3 -mthumb --gdwarf-2
    LDFLAGS = -T CortexM3.ld -M=memmap.map
    OBJCPYFLAGS = -O ihex
    FLOATFLAGS = -mfloat-abi=soft -mfpu=vfp
    LIBDIR = -L C:\\yagarto-20121222\\lib\\gcc\\arm-none-eabi\\4.7.2\\thumb\\v7m -L C:\\yagarto-20121222\\arm-none-eabi\\lib\\thumb\\v7m
    INCDIR = -I C:\\yagarto-20121222\\lib\\gcc\\arm-none-eabi\\4.7.2\\include -I C:\\yagarto-20121222\\arm-none-eabi\\include

    all: m3.elf
    m3.elf: startup.o lowlevelinit.o system_stm32l1xx.o main.o tim6.o exti0_isr.o sensor_MTH01.o comm_BT-HC-05.o
        $(LD) $(LDFLAGS) $(LIBDIR) $^ -lc -lgcc -o $@
        $(OBJCPY) $(OBJCPYFLAGS) m3.elf m3.hex
    startup.o: startup.s
    lowlevelinit.o: lowlevelinit.c system_stm32l1xx.h stm32l1xx.h core_cm3.h
    system_stm32l1xx.o: system_stm32l1xx.c stm32l1xx.h core_cm3.h system_stm32l1xx.h
    main.o: main.c stm32l1xx.h
    tim6.o: tim6.c
    exti0_isr.o: exti0_isr.c
    sensor_MTH01.o: sensor_MTH01.c
    comm_BT-HC-05.o: comm_BT-HC-05.c

    clean:
        -rm -f startup.o lowlevelinit.o system_stm32l1xx.o main.o tim6.o tim6_isr.o exti0_isr.o sensor_MTH01.o comm_BT-HC-05.o memmap.map m3.elf m3.hex

    %.o: %.s
        $(AS) $(ASMFLAGS) $< -o $@
    %.o: %.c
        $(CC) $(CCFLAGS) $(INCDIR) $(FLOATFLAGS) $< -o $@


    .PHONY: all clean 
    ...

can anyone advise?
also, if i come across linking error message like: no memory region specified for loadable section `.rodata'... how can i know which object's (.o) .rodata section is being left out of my linker script?

update: i realized that if the sprintf() function is called in main(), the program can compile and link successfully.. but if i call the sprintf() function in other functions, i will get above linking errors (no memory region specified for loadable section .bss), even if i used *(.bss) as the input sections for my output sections.

foob foob · Accepted Answer · 2014-08-18T02:37:04

To solve the linking errors ('no memory region specified for loadable section .bss etc', i had to add *(COMMON) in the BSS output section.

linking error when using sprintf()

1 Answers