Context switching for VFP registers on Cortex-A8 board.

Thomas Kim thomas73.kim at gmail.com
Tue Dec 2 10:51:15 UTC 2014


Dear Sebastian,

You are correct.

My problem is memory alignment issue from u-boot.

I fixed this for adding below statement.
mrc p15, 0, r0, cr1, cr0, 0
ldr r1, =~0x00000002
and r0, r0, r1
mcr p15, 0, r0, cr1, cr0, 0

Thank you very much.

Best Regards,
Thomas Kim

2014-12-02 19:38 GMT+09:00 Thomas Kim <thomas73.kim at gmail.com>:

> Dear Sebastian,
>
> I used lastest RTEMS source on https://github.com/RTEMS/rtems.
>
> Is there initialization code(start.S) for handling SCTLR.A bit on current
> source tree ?
>
> Best Regards,
> Thomas Kim
>
> 2014-12-02 19:27 GMT+09:00 Sebastian Huber <
> sebastian.huber at embedded-brains.de>:
>
>> Hello,
>>
>> you use a BSP that is not included in the main RTEMS sources, so I can
>> only guess.
>>
>> On 02/12/14 11:16, Thomas Kim wrote:
>>
>>> Dear  Sir.
>>>
>>> I completed to port RTEMS on Cortex-A8 board using below option.
>>>   CPU_CFLAGS = -march=armv7-a -mtune=cortex-a8 -mfpu=neon
>>> -mfloat-abi=softfp
>>> At this time, RTEMS sample example(ticker.exe) is working very well.
>>>
>>> Because there is a problem for executing C++ exception example using
>>> "-mfloat-abi=softfp", I changed below option.
>>>   CPU_CFLAGS = -march=armv7-a -mtune=cortex-a8 -mfpu=neon
>>> -mfloat-abi=hard
>>>
>>> After I rebuild RTEMS using "-mfloat-abi=hard", I am tring to test both
>>> ticker.exe and cxx_throw.exe.
>>> But, both examples are crashed in mount() function of
>>> rtems_filesystem_initialize().
>>> In detailly, memcpy() of alloc_mount_table_entry() is called, exception
>>> is ocurred.
>>>
>>
>> There are many exceptions and some provide extra information, so
>> "exception is occurred" is a very vague description.
>>
>> You probably use the wrong memory attributes.  Make sure misaligned
>> memory access is possible.  See SCTLR.A bit (ARM_CP15_CTRL_A).
>>
>> --
>> Sebastian Huber, embedded brains GmbH
>>
>> Address : Dornierstr. 4, D-82178 Puchheim, Germany
>> Phone   : +49 89 189 47 41-16
>> Fax     : +49 89 189 47 41-09
>> E-Mail  : sebastian.huber at embedded-brains.de
>> PGP     : Public key available on request.
>>
>> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/users/attachments/20141202/d13b6ebe/attachment-0002.html>


More information about the users mailing list