BBB/AM335x: isspace() results in data abort exception in strtol() in strtol.c and strtoul() in strtoul.c

[Gedare Bloom]

On Mon, Jun 22, 2015 at 10:59 AM, Jarielle Catbagan
<jcatbagan93 at gmail.com> wrote:
> On Mon, Jun 22, 2015 at 6:54 AM, Ed Sutter <ed.sutter at alcatel-lucent.com> wrote:
>> On 6/22/2015 8:28 AM, Chris Johns wrote:
>>>
>>> On 22/06/2015 2:16 pm, Jarielle Catbagan wrote:
>>>>
>>>> On Sun, Jun 21, 2015 at 4:47 PM, Chris Johns <chrisj at rtems.org> wrote:
>>>>>
>>>>> On 22/06/2015 2:27 am, Jarielle Catbagan wrote:
>>>>>>
>>>>>> I was testing the "help", "dm" and "pm" commands on the Umon command
>>>>>> line and they resulted in what appears to cause the program to hang.
>>>>>> I captured the result and it can be found here
>>>>>>
>>>>>> https://drive.google.com/file/d/0B_44Dkqbmn75TjQwZjJaczNJYk0/view?usp=sharing.
>>>>>>
>>>>>> After doing some debugging, I was able to pinpoint the location that
>>>>>> results in a halt in program execution.  It hangs when isspace() is
>>>>>> executed in strtol() in strtol.c.
>>>>>>
>>>>> Where do the libc functions come from ? What is the linker command line
>>>>> ?
>>>>>
>>>> isspace() seems to be pulled in just fine from
>>>> /usr/arm-none-eabi/include, because removing <ctype.h> from strtol.c
>>>> results in an undefined reference to isspace().
>>>
>>> My concern is the multilibs and what is needed by umon and what is
>>> needed by RTEMS. For example on the Zynq I build the Xilinx bootloader
>>> code for ARM in thumb mode while Xilinx do not (I know because I needed
>>> to fix it). I actually use the same flags I use for RTEMS.
>>>
>>> With umon having the ability to integrate with RTEMS the need to match
>>> the ABI is important.
>>>
>>>>>> Whenever Umon is built, there are two important images built.
>>>>>> boot.bin and boot.elf.  boot.bin is a raw image and is the image that
>>>>>> is booted on the BBB.  I wanted to see how the image was assembled,
>>>>>> and so I ran "arm-none-eabi-objdump -S boot.elf".  I am focusing on
>>>>>
>>>>>                  ^^^^^^^^^^^^^
>>>>>
>>>>> What tool set is being used ?
>>>>
>>>>
>>>> I am using arm-none-eabi-gcc 4.9.2 and binutils 2.25.0.
>>>>
>>> Where did you get this compiler from ? Who built it ?
>>>
>
> I obtained the compiler from the Arch Linux repositories via "pacman".
>
>>> How do we track what is needed by users ? I for one cannot contribute
>>> because I do not have this compiler.
>>>
>
> I agree, having the same toolset among users and contributors will be
> better in the long run.
>
>>> Why not use the RTEMS compiler ?
>>>
>
> I chose not to modify the existing build process of Umon, (i,e, using
> arm-none-eabi-gcc, etc.), for now.  I am certainly open to the idea of
> transitioning to the RTEMS compiler now, especially if it means that
> complexities would be avoided later down the road.
>
If you switch to the RTEMS arm compiler, you'll pull in newlib
instead, so the problems and solutions may change. It is probably
worth investigating now rather than later.