This is the mail archive of the ecos-discuss@sources.redhat.com mailing list for the eCos project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Running application from RAM without Redboot


On Fri, 2005-04-22 at 14:16 +0200, Jerome Souquieres wrote:
>   Hi,
> 
>   I would like to have some advice about how to fit my specific need 
> within the eCos structure.
> 
>   I have written a package derived from hal\mips\idt79s334a for my own 
> CPU board (IDT32334 MIPS-based microprocessor). So far, so good. 
> However, the way my application is launched is a bit peculiar: I have a 
> ROM monitor (which is NOT Redboot and which I cannot change) that simply 
> loads an hex file at a fixed address in RAM (0x80200000, should that 
> matter). However, to build my application under eCos, I'm in trouble to 
> choose the startup option:
> - CYG_HAL_STARTUP_ROM: is not available for my target. No more discussion.
> - CYG_HAL_STARTUP_ROMRAM: not suitable. I don't need all code to be 
> copied from RAM to ROM, I don't want the SDRAM controller to be 
> configured (because it is obsviously already configured at this point 
> since I'm running from RAM), I don't want the exception vectors to be 
> located in ROM, etc...
> - CYG_HAL_STARTUP_RAM: almost suitable,but this configuration relies on 
> Redboot to provide exception vectors.
> 
>   For now, what I've done is tweaking the CYG_HAL_STARTUP_RAM 
> configuration so that it takes control of exception vectors. This works, 
> but is a bit rough because I've somewhat changed the semantics of 
> CYG_HAL_STARTUP_RAM.
> 
>   Could an eCos architect give me a hint for a proper implementation ? 
> Should I create my own CYG_HAL_STARTUP_xxx ? Should I add a sub-option ? 
> Another idea ?

CYG_HAL_STARTUP_RAM is the right mode to use.  All you probably need is
to make sure that CYGSEM_HAL_USE_ROM_MONITOR is disabled.  In this 
setup, your application should take over the hardware completely, 
initializing all the exceptions and I/O

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


-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]