Reducing RTEMS size to <32KB to fit in Epiphany local memories

[Daniel Gutson]

Maybe it's worth to mention the 20k or so EH-related buffers?
I think they go away when building the STL without EH and RTTI support,
right?

On Wed, Dec 17, 2014 at 2:44 PM, Marcos Díaz <
marcos.diaz at tallertechnologies.com> wrote:
>
> That particular test I could see it uses like four tasks. The problem we
> had in the past is that the predefined size for the stack for each task was
> set to 4k for our architecture (arm cortex m3). We proposed a patch in
> order to make the default stack size for each bsp configurable. Im not sure
> if it has been submitted
>
> #define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
> #define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
>
> #define CONFIGURE_MAXIMUM_TASKS             4
>
> #define CONFIGURE_RTEMS_INIT_TASKS_TABLE
>
> #define CONFIGURE_EXTRA_TASK_STACKS         (3 * RTEMS_MINIMUM_STACK_SIZE)
>
> #define CONFIGURE_INITIAL_EXTENSIONS RTEMS_TEST_INITIAL_EXTENSION
>
> this is extracted from the "system.h" file of ticker test.
>
> If your objective is to have that test working, i suggest to tune the
> minimum stack size in this file.
> If you want to know a little more, I suggest that you make a objdump and
> see what global objects are using more RAM and where did they come from.
>
> On Wed, Dec 17, 2014 at 1:36 PM, Daniel Gutson <
> daniel.gutson at tallertechnologies.com> wrote:
>>
>> We were able to downsize RTEMS to about 9k for the LPC1768.
>> Marcos, could you give a hint?
>>
>> On Wed, Dec 17, 2014 at 1:34 PM, Joel Sherrill <joel.sherrill at oarcorp.com
>> > wrote:
>>>
>>>
>>>
>>> On December 17, 2014 8:00:50 AM PST, Hesham Moustafa <
>>> heshamelmatary at gmail.com> wrote:
>>> >Hi all,
>>> >
>>> >I am working on reducing RTEMS size to fit into <32KB as every Epiphay
>>> >core has only 32KB of local memory. I was able to get hello and
>>> >minimum samples with aggressive size reduction by manually removing
>>> >un-needed code. Currently I only use libcsupport, sapi, score, rtems
>>> >built for cpukit only, and for each, some source code files were
>>> >removed. No IO, no FS, no barrier, event, managers are included.
>>>
>>> Our minimum is where it is because no one has provided lower
>>> requirements. Some of the things you dropped out could be addressed by
>>> initialization being more like a constructor table that is automatically
>>> built based on dependencies. This was/is the sequenced initialization
>>> project. I don't know the state of it.
>>>
>>> Try turning on per section methods and data like the SPARC bsps. This
>>> saves memory.
>>>
>>>
>>> Defining which features are part of 'nanoRTEMS' is a big part of this.
>>> Then those requirements can drive dropping things not covered by sequenced
>>> initialization and finer tuning.
>>>
>>> Using printk saves a lot of memory.
>>>
>>> >And I
>>> >added -Os flag. However when building ticker, the .text area overflows
>>> >the 32KB local memory by about 8KB.
>>> >
>>> >The question is, what are the very basic mandatory sources/libraries
>>> >and/or managers that are enough to build ticker?
>>>
>>> Some of that is stack size in ticker. Look at the ticker variants in
>>> examples-v2
>>>
>>> >Regards,
>>> >Hesham
>>> >_______________________________________________
>>> >devel mailing list
>>> >devel at rtems.org
>>> >http://lists.rtems.org/mailman/listinfo/devel
>>>
>>> --joel
>>> _______________________________________________
>>> devel mailing list
>>> devel at rtems.org
>>> http://lists.rtems.org/mailman/listinfo/devel
>>>
>>
>>
>> --
>>
>> Daniel F. Gutson
>> Chief Engineering Officer, SPD
>>
>> San Lorenzo 47, 3rd Floor, Office 5
>> Córdoba, Argentina
>>
>> Phone:   +54 351 4217888 / +54 351 4218211
>> Skype:    dgutson
>> LinkedIn: http://ar.linkedin.com/in/danielgutson
>>
>
>
> --
>
> ______________________________
>
> <http://www.tallertechnologies.com>
>
>
> Marcos Díaz
>
> Software Engineer
>
>
> San Lorenzo 47, 3rd Floor, Office 5
>
> Córdoba, Argentina
>
>
> Phone: +54 351 4217888 / +54 351 4218211/ +54 351 7617452
>
> Skype: markdiaz22
>
>

-- 

Daniel F. Gutson
Chief Engineering Officer, SPD

San Lorenzo 47, 3rd Floor, Office 5
Córdoba, Argentina

Phone:   +54 351 4217888 / +54 351 4218211
Skype:    dgutson
LinkedIn: http://ar.linkedin.com/in/danielgutson
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