strange, spurious seeming vector exception on pxa300

[Eric Miao]

On Wed, Dec 2, 2009 at 2:00 PM, Eric Miao <eric.y.miao at gmail.com> wrote:
> On Wed, Dec 2, 2009 at 6:13 AM, Yeasah Pell <yeasah at comrex.com> wrote:
>> Has anybody ever seen vector exceptions happen on an ARM (xscale, pxa300)
>> without 26-bit mode being used? I have some application and kernel code
>> which appears to work on most hardware, but we have at least one board which
>> causes periodic messages:
>>
>> Unhandled fault: vector exception (0x010) at 0x412c8a90
>>
>> (I also fudged the fault handler a bit to dump the SPSR: 0x80000010)
>
> Never had such exceptions. This is weird, SPSR[4] == 1 indicates a 32-bit mode.

When the processor is in a 32-bit configuration (PROG32 is active) and
in a 26-bit mode (CPSR[4] == 0),
data access (but not instruction fetches) to the exception vectors
(address 0x0 to 0x1f) causes a data abort.
This is known as a vector exception.

This is what explained in the manual, seems something related to 26-bit mode.
What's your compiling environment and flags for your application?