Re: Restricted or no run time in Ada

[Lucretia <lucretia9@lycos.co.uk>]

On Jan 2, 8:49 pm, a...@anon.org (anon) wrote:
> Your going down the wrong path!
>
> First, there is no "pragma" other than "pragma No_Run_Time;" that
> will allow GNAT to build code without a runtime code. Even then,
> the code is not ROM bootable.

That pragma is deprecated for a start.

Why wouldn't it be ROM bootable?

> Second, The Ada main procedure (Ada program) has no startup address
> or routine that can be directly linked and make a kernel, that can be
> executed by a ROM startup! You must use the BINDER process to build
> that start code. But the "GNAT BIND" does not allow stand-alone aka
> ROM bootable kernel.

In my test I create a simple bit of asm that gets called by grub and
then it boots into my main Ada application. I also link with LD.

> The GNAT binder perform a number of steps, that have to be preform
> to insure that the program will work properly. Such as:
>         1. Checks that a program is consistent [ RM 10 ].

True enough.

>         2. Checks that an acceptable order of elaboration exists
>            for the program [ RM 10 ].

This was something I was worried about.

>         3. Generates a main program incorporating the given
>            elaboration order. This program is a small Ada package
>            (body and spec) that must be subsequently compiled
>            using the GNAT compiler.
>         4. Determines the set of object files required by the
>            given main program.
>
> So, for Ada only code, you must write a new Ada binder to preform
> those steps to build a stand-alone code. And create the main program
> (describe in step 3) that allows ROM bootable programs..

Or use the gnatbind as a base.

> Time allowed just to write and test as new binder 6 months at least!
>
> Another way is to use existing Ada 95 code projects that are out there.
> That you can download the source code and study how they got around
> this. But this way mean no Ada only code, and does violates the Ada RM.

MarteOS actually uses gnat, they have ported the compiler to their os.
I don't know if it uses gnatbind. Not sure of pragmas either.

How do big companies use GNAT to create ROM bootable applications
then?

Luke.