Re: [ECOS] RedBoot ROM resource management after loading RAM eCos application.

[Andrew Lunn <andrew at lunn dot ch>]

On Tue, Feb 21, 2006 at 11:32:44AM -0800, Chuck McManis wrote:
> At 05:12 AM 2/21/2006, Andrew Lunn wrote:
> >Yes, it needs some RAM. Normally redboot provides the hal diag tty
> >communication channel, gdb talks to redboot, etc. It needs RAM to do
> >this. The linker script is setup so that Redboot gets the lowest part
> >of RAM and the application is loaded above this. eg
> 
> [snip]
> 
> This raises another interesting point.
> 
> For grins & giggles i tried building and then loading the "simple 
> application" from the book on my system and Redboot complained that it 
> couldn't load because doing so would cause it to commit suicide. Basically, 
> on the i386 platform, when you've selected GRUB as a startup for Redboot, 
> Redboot loads at 0x00108000 which is the same address that applications 
> attempt to load.

     cdl_option CYGHWR_HAL_I386_PC_LOAD_HIGH {
         display       "Load into higher memory (2MB)"
         flavor        bool
         default_value 0
         requires { CYG_HAL_STARTUP == "RAM" || CYG_HAL_STARTUP == "GRUB" }

         no_define
         description "This option enables building RAM applications
                      which have a start address outside of the area
                      used by redboot_GRUB."
     }

     Andrew

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