Hi Tamas,

    Good suggestion - I need to learn how to do this sort of thing (and =

anything for that matter) with scripts - another on my long list of todo =

projects.

Thanks,

Tony


Tamas Rudnai wrote:
>> You could put a 'jump table' at a fixed location in your bootstrap's
>> program space, with each entry jumping to one routine that you may call
>> from your application.
>>     =

>
> Or you can use the MAP file to figure out the function entries and some
> Perl/Python scripts to generate a similar function declaration as mention=
ed
> by Isaac. You could then put that script into the tool path so that it wi=
ll
> run automatically every time you compile your application, so it will nev=
er
> out of sync.
>
> Tamas
>
>
> On Mon, Jan 19, 2009 at 10:57 AM, Isaac Marino Bavaresco <
> isaacbavaresco@yahoo.com.br> wrote:
>
>   =

>> Tony Vandiver escreveu:
>>     =

>>> I'm trying to write a custom bootstrap to load in my application code
>>> from an SD card.  I want to call file I/O routines located in my
>>> bootstrap from my application rather than duplicating the file I/O
>>> library functions in the application because it represents about 10% of
>>> my code space.  Typically when I compile, I compile and link everything
>>> that pertains to a project at the same time, but in this instance, do I
>>> need to reference an object file from the bootstrap compilation without
>>> compiling it into the application project, and if so, how do I keep it
>>> from being relocated by the linker without expressly setting the address
>>> of each function?  I'll start reading the compiler reference material
>>> now and see how long it will take me to start drooling.
>>>
>>> Thanks for the help,
>>>
>>> Tony
>>>
>>>       =

>> You could put a 'jump table' at a fixed location in your bootstrap's
>> program space, with each entry jumping to one routine that you may call
>> from your application.
>>
>> The reason for the 'jump table' is to make the entry points fixed, even
>> if you change your bootstrap code.
>>
>> Assuming you are using MPLAB C18 (other Cs may have a slightly different
>> syntax, but not much even for other MCUs).
>>
>> In the bootstrap:
>>
>> #pragma code JUMPTABLE =3D 0x1f000
>>
>> void JumpTable( void )
>>    {
>>    _asm
>>    goto mount;
>>    goto remove;
>>    goto ...
>>    _endasm;
>>    }
>>
>> #pragma code
>>
>> In your application you call the functions this way:
>>
>> typedef void (*func_type1)( void );   // Pointer to a function that take
>> void and return void;
>> typedef int (*func_type2)( const char rom * );   // Pointer to a
>> function that take a string and return int;
>> ....
>>
>> #define mount() ((func_type1)0x1f000)() /* mount entry point is at
>> 0x1f000 */
>> #define remove(name) ((func_type2)0x1f004)(name) /* remove entry point
>> is at 0x1f004 */
>> ....
>>
>> void main( void )
>>    {
>>    mount();
>>    remove( "backup.bin" );
>>    }
>>
>> Best regards,
>>
>> Isaac
>> __________________________________________________
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>>
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>>     =

>
>
>
>   =

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