On Tue, Jul 28, 2015 at 5:51 AM, Pavel Pisa <ppisa4li...@pikron.com> wrote:
> Hello Rohini and Gedare, > > On Friday 24 of July 2015 15:33:03 Gedare Bloom wrote: > > 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. > > > > Qiao Yang in RPi 1 BSP now works in the similar > area to enable right graphic memory mapping. > > So my guess is that there could be problem caused > by used MMU mode granularity, which is is 1 MB so > if RO and RW sections are present in the same 1MB > aligned block ten there can be problem. It depends > which section is filled the first. If data and then > text (RO) the troubles begin. If the order is vice > versa then some part of text can be RW instead of RO, > but it should work and cache should not be a problem. > > But I have not dig into this case too much. > Only short glimpse. > > One option is to define 1 MB alignment between text > ad data for RPi case. There is quite a lot of memory > when compared to most RTEMS embedded targets to the > waste is not so important. > I didn't quite get what this means. I have no clue on how to proceed with this. > > Best wishes, > > Pavel > > On Friday 24 of July 2015 21:55:00 Rohini Kulkarni wrote: > > Hi, > > > > I have attached the report containing outputs of arm-rtems4.11-size and > > arm-rtems4.11-nm -S. > > > > From arm-rtems4.11-nm -S I don't see how memset() is accessing .text > > section. The start and end values for both are not overlapping. > > > > On Fri, Jul 24, 2015 at 7:03 PM, Gedare Bloom <ged...@gwu.edu> wrote: > > > On Fri, Jul 24, 2015 at 3:30 AM, Rohini Kulkarni < > krohini1...@gmail.com> > > > > > > wrote: > > > > On 24 Jul 2015 12:35, "Sebastian Huber" < > > > > > > sebastian.hu...@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/ar > > >m/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.hu...@embedded-brains.de > > > >> PGP : Public key available on request. > > > >> > > > >> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des > EHUG. > > > > > > > > _______________________________________________ > > > > devel mailing list > > > > devel@rtems.org > > > > http://lists.rtems.org/mailman/listinfo/devel > > -- Rohini Kulkarni
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