Re: Reboot when running program with two .c files

Altera_Forum · ‎05-30-2006

I wrote a very simple test program that runs just fine:

int main(int argc, char *argv)
{
  unsigned char *p = (unsigned char *) malloc(2048*sizeof(unsigned char));
  printf("Allocation via malloc() succeeded\n");
  free(p);
}

I am not using the NIOS II IDE to build the application, rather I use a Makefile and build from the command line. I altered this test program every so slightly, by simply moving the code that appears in main to its own separate .c file, as shown below.

test_malloc.c:

extern void foo(void);
int main(int argc, char *argv)
{
  foo();
}

foo.c:

#include <unistd.h># include <stdlib.h># include <stdio.h>
void foo()
{
  unsigned char *p = (unsigned char *) malloc(2048*sizeof(unsigned char));
  printf("Allocation via malloc() succeeded\n");
  free(p);
}

This builds, but when I run it I think I'm getting a crash. uClinux reboots - this is very strange, and I am wondering if it has something to do with my makefile and how I am linking things. Perhaps my arguments to elf2flt are incorrect? Any help would be most appreciated, and my Makefile follows.

include ../Rules.mak
VERSION=$(shell cat ../../VERSION)
CFLAGS += $(INCLUDES) -O2 -nostdinc -Wall -DLINUX -g
SRC = test_malloc.c foo.c
OBJ = $(addsuffix .o, $(basename $(SRC)))
LIBDIRS += -L/cygdrive/c/Altera/kits/nios2_51/bin/eclipse/plugins/com.microtronix.nios2linux.uClibc_1.4.0/lib
LDFLAGS += -elf2flt
LIBS += -lc
all: test_malloc.exe
test_malloc.exe: $(OBJ) Makefile#        $(CC) -o $@ $(OBJ) $(LIBDIRS) $(LIBS)#        $(CC) $(CFLAGS) $< -o $@
install: all
        cp test_malloc.exe /cygdrive/c/opt/toga/linux_root/home/
clean:
        rm -f test_malloc.exe $(OBJ)
.PHONY: all install uninstall clean

Altera_Forum · ‎05-30-2006

hi,

--first thing :u try to allocate 2048 of unsigned char which is equal to 2 Mb, I think it's to much ! regardless your RAM size ?

--seconde thing : to know that malloc() succeded u must do a test like :

if (p =! NULL) then ...

so I advice u to reduce the allocation size (something like 512 bytes). http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/rolleyes.gif

best regards.

Altera_Forum · ‎05-31-2006

--- Quote Start ---

originally posted by sdhnain@May 30 2006, 11:01 AM

hi,

--first thing :u try to allocate 2048 of unsigned char which is equal to 2 mb, i think it's to much ! regardless your ram size ?

--seconde thing : to know that malloc() succeded u must do a test like :

if (p =! null) then ...

so i advice u to reduce the allocation size (something like 512 bytes). http://forum.niosforum.com/work2/style_emoticons/<#emo_dir#>/rolleyes.gif

best regards.

<div align='right'><{post_snapback}> (index.php?act=findpost&pid=15693)</div>

--- Quote End ---

Well I sure hope 2K bytes isn't 2 MB, I believe that would be 2 KB. Regardless, no matter what amount I try and malloc() uClinux reboots. Note that when I "inline" the code into a single .c file, everything works just fine, which leads me to believe that this is a linker problem of some sort.

Also, I am aware that I should be checking the value of the returned pointer from malloc(), but in the second case (test_malloc.c and foo.c), I never even get that far, my board resets (seg faults?) right when the call to foo() is made.

-SQ

Altera_Forum · ‎05-31-2006

Never mind - I figured out the problem. It was indeed a linker problem, or rather a build problem. I fired up Eclipse and created a project in the IDE, using one of the busybox Makefiles as a template. My test program, consisting of two .c files, then ran correctly.

Thanks again,

-SQ

Altera_Forum · ‎05-31-2006

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originally posted by squreshi@May 31 2006, 01:37 PM

never mind - i figured out the problem. it was indeed a linker problem, or rather a build problem. i fired up eclipse and created a project in the ide, using one of the busybox makefiles as a template. my test program, consisting of two .c files, then ran correctly.

thanks again,

-sq

<div align='right'><{post_snapback}> (index.php?act=findpost&pid=15708)

--- quote end ---

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If you work on Linux and install the binary toolchain,

http://nioswiki.jot.com/wikihome/operating...binarytoolchain (http://nioswiki.jot.com/wikihome/operatingsystems/binarytoolchain)

Then it is easy to compile the test program without even a Makefile.

http://nioswiki.jot.com/wikihome/operating...ms/compilehello (http://nioswiki.jot.com/wikihome/operatingsystems/compilehello)

Just,

nios2-linux-uclibc-gcc test_malloc.c foo.c -o test_malloc -elf2flt