Re: [ECOS] Is there any way to branch in Boot Script

[Sergei Gavrikov <w3sg at SoftHome dot net>]

On Wed, Jul 18, 2007 at 09:09:07PM +0300, Sergei Gavrikov wrote:
> On Tue, Jul 17, 2007 at 04:37:33PM +0900, ariga masahiro wrote:
> > Hi,Everyone,
> > 
> > I beseech you to help me out of next predicament.
> > 
> > What I want to do is this:
> >  In RedBoot Boot Script,read Target Board DIPSW-settled value,
> >  and compare already-written value in a certain address.
> > ã(for example,use mcmp command)
> >  If same, continue next Boot Script command.
> >  If differs,quit Boot Script and return to RedBoot's prompt.
> > 
> > My questions are:
> >  1.Is there any way to know mcmp result(that is ,succeeded or errored).
> >    Preferably in RedBoot Boot Script.
> > ã2.Is there any way to use branching statement(like,if-else),
> >    in RedBoot Boot Script
> 
> It's pity, but RedBoot != shell, so it hasn't such behaviours. Some guys
> dream about those behaviours :-) But, every RedBoot command (redboot.h)
> is just it
> 
> typedef void cmd_fun(int argc, char *argv[]);
> 
> Therefore, it is no way to return any result (Ups, I did think about
> `argv' :). Also, there is no global variable, something like the DOS
> `errorlevel' (to check/collect the fails) there. More that, if the
> RedBoot's parser does meet wrong line in a script, it passes the line a
> bit noisely and then it continues to parse a rest of the script.
>  
> >  3.Is there any way to realize above-mentioned "what I want to do".
> 
> I had same needs (to read the DIP switches). And I did use such a way.
> Well, if your RedBoot/eCos aren't fucked binaries, i.e. if you have the
> target sources, you can put same stuff in your plf_misc.c file
> 
> ---------------------------------------------------------->8
> #include <pkgconf/system.h>
> 
> #ifdef CYGPKG_REDBOOT
> #include <redboot.h>            // script declaration
> 
> #define DIPSW_MASK (1 << 7)     // FIXME: put yours
> 
> #ifdef CYGSEM_REDBOOT_PLF_STARTUP
> void
> cyg_plf_redboot_startup (void)
> {
>     int             switches = 0;
> 
>     // put a code to read the switches here
> 
>     if (switches & DIPSW_MASK)
>         // don't run the script
>         script = 0;
> }
> #endif // CYGSEM_REDBOOT_PLF_STARTUP
> #endif // CYGPKG_REDBOOT
> ---------------------------------------------------------->8
> 
> Note: before to build RedBoot with this tweak, set this option in your
> `ecos.ecc':
> 
> cdl_option CYGSEM_REDBOOT_PLF_STARTUP {user_value 1};
> 
> For more details, look at cyg_start () in redboot/current/src/main.c,
> you would find your own way for that.
> 

A bit more, redboot.cdl contains yet another option... So, with a code
above, you can run an alternate script instead default one, if you put
there something like this

cdl_option CYGDAT_REDBOOT_DEFAULT_BOOT_SCRIPT {1 {alt_script}};

Note: a declaration/filling that `alt_script' is your deal, certainly.

Sergei

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