[PATCH] GSoC: Cache configurations Raspberry Pi 2 support

[Gedare Bloom]

On Fri, Jul 24, 2015 at 3:30 AM, Rohini Kulkarni <krohini1593 at gmail.com> wrote:
> On 24 Jul 2015 12:35, "Sebastian Huber" <sebastian.huber at embedded-brains.de>
> wrote:
>>
>>
>>
>> On 23/07/15 23:24, Rohini Kulkarni wrote:
>>>
>>> I could finally get back to this issue. I used Pi 1 for debugging, but
>>> the reason for this problem will apply to Pi 2 also.
>>> With text section set to ARMV7_MMU_CODE_CACHED ( which implies read only)
>>> , a data abort exception occurs with memset() inside bsp_start_clear_bss()
>>> function. An illegal write access to an address according to me.
>>
>>
>> Which exception and which address? Something is not working here.
>
>
> This is a part of the debugging output. When I used ARMV7_MMU_CODE_CACHED.
> (gdb) s
> bsp_start_clear_bss ()
>     at ../../../../../.././raspberrypi/lib/include/bsp/start.h:126
> 126      memset(bsp_section_bss_begin, 0, (size_t) bsp_section_bss_size);
What are the values of bsp_section_bss_begin, and bsp_section_bss_size?

Apparently, the memset is trying to write into the .text (code)
section, which is a very bad thing to do indeed.

> (gdb) s
> memset (m=0x1157e0, c=0, n=64176)
>     at ../../../../../gcc-4.9.2/newlib/libc/string/memset.c:59
> 59    ../../../../../gcc-4.9.2/newlib/libc/string/memset.c: No such file or
> directory.
> (gdb) s
> 49    in ../../../../../gcc-4.9.2/newlib/libc/string/memset.c
> (gdb) s
> _ARMV4_Exception_data_abort_default ()
>     at
> ../../../../../../../../rtems-local/rtems/c/src/../../cpukit/score/cpu/arm/armv4-exception-default.S:71
> 71        sub    sp, #MORE_CONTEXT_SIZE
>
> When I set text section flag to ARMV7_MMU_READ_WRITE, the system starts
> successfully.
>>
>>
>> --
>> 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.
>>
>
> _______________________________________________
> devel mailing list
> devel at rtems.org
> http://lists.rtems.org/mailman/listinfo/devel