AW: Mess with library

Hi Bob

Printf() will need to send the output to an interface - one of the UARTs
normally. The printf() code interfaces with the UART using the puts()
call, which accepts the characters to be sent and transmits them to the
UART.
If you are getting a linker error due to this not being found you will
need to use a hardware library which performs it (BSP or something).

Since I don't use the same tools as you I can't say exactly which is
required, but this may help you start looking in the right direction.

Regards

Mark


 
Mark Butcher Bsc (Hons) MPhil MIEE
 
M.J.Butcher Consulting                
Obere Bahnhofstr. 13,  CH-5507 Mellingen,
Switzerland         www.mjbc.ch / www.uTasker.com
056 491 48 10 / 079 402 26 37 / Skype: M_J_Butcher
 
 
 

-----Ursprüngliche Nachricht-----
Von: [email protected] [mailto:[email protected]]
Im Auftrag von Bob Brusa
Gesendet: Donnerstag, 24. Januar 2008 17:14
An: [email protected]
Betreff: [ColdFire] Mess with library

Hi,
I am using the toolchain uClinux (m68k-uclinux-tools-20061214.sh) on a  
Debian (etch) host. The Target is a COBRA5282-Board which operates under

dBUG. The Board came with an example that blinks with the LEDs on the  
board. The program links with its own target-specific startfile crt0_ram

and no libraries. It compiles, links and I can download (using NFS) and

execute it. So far so good. Then I wanted to create another example - a

simple HelloWorld-Programm. But I get an error. The output is shown
below:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+++++++++
rwb@debi28:~/wso/helloworld$ make
/usr/local/bin/m68k-elf-gcc -Wa,-as -m5307 -c crt0_ram.S
68K GAS  /tmp/ccrsskya.s                        page 1


DEFINED SYMBOLS
                             *ABS*:00000000 crt0_ram.S
           crt0_ram.S:39     .text:00000000 _start

UNDEFINED SYMBOLS
main
/usr/local/bin/m68k-elf-gcc -g -m5307 -nostartfiles -c main.c
/usr/local/bin/m68k-elf-ld -T COBRA5282-ram.ld -M -o helloworld.elf  
crt0_ram.o main.o > helloworld.map
main.o: In function `main':
/home/rwb/wso/helloworld/main.c:5: undefined reference to `puts'
make: *** [helloworld.elf] Fehler 1
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+++++++++++
It seems, something is wrong with the standard library. Who can help? So

far I have found nothing that explains the linking process in some  
details. Yes, I have the ld-doc, but it does not explain the basics
(which  
I am sorry to say - I do not know yet).

Regards Bob

The source (main.c) is shown below:
-----------------------------------------------
#include <stdio.h>

int main(void)
{
	printf("Hello World\n");
	return 0;
}
------------------------------------------------
The makefile, adapted from the led-example - is:
------------------------------------------------

GCC_EXEC_PREFIX = /usr/local/bin/m68k-elf-

CC = $(GCC_EXEC_PREFIX)gcc
AS = $(GCC_EXEC_PREFIX)as
LD = $(GCC_EXEC_PREFIX)ld
AR = $(GCC_EXEC_PREFIX)ar
OBJCOPY = $(GCC_EXEC_PREFIX)objcopy

PROGNAME = helloworld

TARGET = $(PROGNAME).s19
OBJS = crt0_ram.o main.o

CFLAGS += -g -m5307
# -g produces debugging options (native format)
# -m5307 selects the processor. this options is also ok for the MCF5282.
# the -as option for the assembler is nowhere documented
ASFLAGS += -Wa,-as -m5307

$(PROGNAME).s19: $(PROGNAME).bin
# objcopy converts the binary file to the srec format - .bin to .s19
	$(OBJCOPY) --input-target=binary --output-target=srec
$(PROGNAME).bin  
$(PROGNAME).s19
# and the .s19-file is copied to our network-folder
	cp ${PROGNAME}.s19 /tftpboot

$(PROGNAME).bin: $(PROGNAME).elf
# create a binary file using the standard .elf-file as input
	$(OBJCOPY) -O binary $(PROGNAME).elf $@
# and copy the .bin-file to our network-folder
	cp ${PROGNAME}.bin /tftpboot

$(PROGNAME).elf: $(OBJS)
# Link the o-files into memory as specified in the .ld-file  
(linker-script-file)
	$(LD) -T COBRA5282-ram.ld -M -o $(PROGNAME).elf $(OBJS) >
$(PROGNAME).map

.S.o:
	$(CC) $(ASFLAGS) -c $<
.c.o:
	$(CC) $(CFLAGS) -nostartfiles -c $<
#compile c-files, but no linking
crt0_ram.o: crt0_ram.S	

all:	$(TARGET)

clean:
	rm $(PROGNAME) *.o *.bin *.s19 *.map *.elf *.gdb -f

------------------------------------------------------------------
and the loader script (COBRA5282-ram.ld) is:
------------------------------------------------------------------

MEMORY {
      ram    : ORIGIN = 0x10000, LENGTH = 0x3e0000
}

SECTIONS {

         .text : {
		_stext = . ;
         	*(.text)
		_etext = ALIGN(0x4) ;
         } > ram

         .data BLOCK(0x4) : {
		_sdata = . ;
		__data_start = . ;
		*(.rodata)
         	*(.data)
		_edata = ALIGN(0x4) ;
         } > ram

         .bss BLOCK(0x4) : {
		_sbss = . ;
		*(.bss)
		*(COMMON)
		_ebss = ALIGN(0x4) ;
		_end = ALIGN(0x4) ;
	} > ram
     __main = main;

}
-------------------------------------------------------------

-- 
Bob Brusa                [email protected]
Chapfwiesenstr. 14       ph: +4144 926 74 74
CH-8712 Stäfa            fx:   +4144 926 73 34
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