Re: physmem, simple containers

[Johan Rydberg]

address@hidden (Niels Möller) wrote:

: But what about WORTEL_MSG_GET_CAP_REPLY? Despite its name, it is sent
: by physmem to wortel (like all the other wortel requests). It seems
: intended for having physmem give some capability to wortel. Exactly
: what is it that physmem should give wortel? (My guess was that it
: simply returns a container handle for the memory passed in the
: corresponding WORTEL_MSG_GET_CAP_REQUEST, but it seems I guessed
: wrong).

As you said, physmem gives a container cap for the module memory
sent by worten in the respond to WORTEL_MSG_GET_CAP_REQUEST.  Also,
after the final module, physmem sends a master control cap to wortel.  

If I've understood things correctly, WORTEL_MSG_GET_CAP_REPLY will
also be used to signal to wortel that the module can be started.

In my hacked version of physmem/wortel I also let physmem pass a 
mapping with WORTEL_MSG_GET_CAP_REPLY, which holds a piece of memory
that will be the startup page for the module.

The code looks like this:

          if (mod_idx > mods_count)
            panic ("Invalid get cap reply message");
          else if (mod_idx == mods_count)
            physmem_master = l4_msg_word (&msg, 1);
          else
            {
              l4_map_item_t map;

              l4_msg_get_map_item (&msg, 0, &map);
              mods[mod_idx].mem_cont = l4_msg_word (&msg, 1);
              mods[mod_idx].startup_code = map.send_fpage;
            }


-- 
Johan Rydberg, Free Software Developer, Sweden
http://rtmk.sf.net | http://www.nongnu.org/guss/

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