[ECOS] Re-use RedBoot RAM segment in the application

[ECOS] Re-use RedBoot RAM segment in the application

[Elad Yosef]

Hi all,
My Target is short with RAM and I want to use the RedBoot RAM in the
application as well.
Is it possible? it is a waste of RAM if not.

Elad

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Re: [ECOS] Re-use RedBoot RAM segment in the application

[Gary Thomas]

On 07/01/2011 06:28 AM, Elad Yosef wrote:
> Hi all,
> My Target is short with RAM and I want to use the RedBoot RAM in the
> application as well.
> Is it possible? it is a waste of RAM if not.

It's only a waste if your application does not use RedBoot for
runtime services.  By default, your code will call functions in
RedBoot for such things as console I/O, network debug support,
GDB support, etc.  You can only reuse RedBoot's RAM section if
you are not using any of those (CYGSEM_HAL_USE_ROM_MONITOR == 0)

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

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Re: [ECOS] Re-use RedBoot RAM segment in the application

[Elad Yosef]

But My RedBoot code is running directly from the ROM.
What you are saying is that when the application is calling "UART
write" for example
The code which runs is the RedBoot code from the ROM, which I agree about it.
But all the parameters I think they are located on the calling
Thread's stack, Am I wrong here?

Elad


On Fri, Jul 1, 2011 at 3:38 PM, Gary Thomas <gary@mlbassoc.com> wrote:
> On 07/01/2011 06:28 AM, Elad Yosef wrote:
>>
>> Hi all,
>> My Target is short with RAM and I want to use the RedBoot RAM in the
>> application as well.
>> Is it possible? it is a waste of RAM if not.
>
> It's only a waste if your application does not use RedBoot for
> runtime services.  By default, your code will call functions in
> RedBoot for such things as console I/O, network debug support,
> GDB support, etc.  You can only reuse RedBoot's RAM section if
> you are not using any of those (CYGSEM_HAL_USE_ROM_MONITOR == 0)
>
> --
> ------------------------------------------------------------
> Gary Thomas                 |  Consulting for the
> MLB Associates              |    Embedded world
> ------------------------------------------------------------
>

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Re: [ECOS] Re-use RedBoot RAM segment in the application

[Gary Thomas]

On 07/03/2011 12:50 AM, Elad Yosef wrote:
> But My RedBoot code is running directly from the ROM.
> What you are saying is that when the application is calling "UART
> write" for example
> The code which runs is the RedBoot code from the ROM, which I agree about it.
> But all the parameters I think they are located on the calling
> Thread's stack, Am I wrong here?

Even when RedBoot runs in ROM, there are static data which it uses (not
everything can be kept on stacks).

As I said below (top posting is evil BTW), if your application is built
with CYGSEM_HAL_USE_ROM_MONITOR == 1, then you *will* need the data
segment of RedBoot to remain intact.

> On Fri, Jul 1, 2011 at 3:38 PM, Gary Thomas<gary@mlbassoc.com>  wrote:
>> On 07/01/2011 06:28 AM, Elad Yosef wrote:
>>>
>>> Hi all,
>>> My Target is short with RAM and I want to use the RedBoot RAM in the
>>> application as well.
>>> Is it possible? it is a waste of RAM if not.
>>
>> It's only a waste if your application does not use RedBoot for
>> runtime services.  By default, your code will call functions in
>> RedBoot for such things as console I/O, network debug support,
>> GDB support, etc.  You can only reuse RedBoot's RAM section if
>> you are not using any of those (CYGSEM_HAL_USE_ROM_MONITOR == 0)

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

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