This is the mail archive of the ecos-discuss@sourceware.org mailing list for the eCos project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Re: Dividing by zero does NOT generate exception


Hi Grant,

The hardware is KwikByte KB9200 board from eCosCentric, which is based
on the ARM9 AT91RM9200 processor. But more RAM and ROM are added.

I am new to the ARM architecture.  Can someone confirm the processor
does NOT generate exception on dividing by 0?

Another odd thing I found is that It does NOT generate bad memory
alignment exception either.
For example, the following code will run just fine:

unsigned int addr=0x00040041;
*(int *)addr=0xFEFEFEFE;

Should it generate a bad alignment exception?

To me, it seems that either all the exceptions are blocked by HAL, or
the hardware does not generate exception at all.  How can I find out
which case is true?

I looked the file vectors.S. Is there any way I can find out any of
the exception handler got invoked by printing out in the console?  Of
course, I can NOT call diag_printf() in vector.S, I mean by doing
something similar but in assembly.  Because I can not do hardware
debuging like using JTAG.

Thanks



On Fri, Mar 4, 2011 at 6:20 PM, Grant Edwards <grant.b.edwards@gmail.com> wrote:
> On 2011-03-04, Grant Edwards <grant.b.edwards@gmail.com> wrote:
>> On 2011-03-04, Quanren Xiong <xiongqr@gmail.com> wrote:
>>
>>> I am using ECOS 2.0.33. ?To my suprise, the following code does NOT
>>> generate an exception.
>>>
>>> "int b=1; int c=b/0;" The value in variable c will be 0.
>
>> You're expecting a run-time exception from something that doesn't
>> actually execute at runtime.
>
> I think I got that one wrong. ?For some reason I convinced myself you
> were talking about static variables, but the second initialize isn't
> lebal for a static initializer.
>
> Perhaps your processor doesn't generate an exception for integer
> divide by zero?
>
> --
> Grant Edwards ? ? ? ? ? ? ? grant.b.edwards ? ? ? ?Yow! The PINK SOCKS were
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?at ? ? ? ? ? ? ? ORIGINALLY from 1952!!
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?gmail.com ? ? ? ? ? ?But they went to MARS
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? around 1953!!
>
>
> --
> Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
> and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
>
>

--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]