[image] Simplify image management

Refactor the {load,exec} image operations as {probe,exec}.  This makes
the probe mechanism cleaner, eliminates some forward declarations,
avoids holding magic state in image->priv, eliminates the possibility
of screwing up between the "load" and "exec" stages, and makes the
documentation simpler since the concept of "loading" (as distinct from
"executing") no longer needs to be explained.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/image/embedded.c

@@ -76,10 +76,10 @@ static void embedded_init ( void ) {
 		}
 	}
 
-	/* Load the first image */
+	/* Select the first image */
 	image = &embedded_images[0];
-	if ( ( rc = image_autoload ( image ) ) != 0 ) {
-		DBG ( "Could not load embedded image \"%s\": %s\n",
+	if ( ( rc = image_select ( image ) ) != 0 ) {
+		DBG ( "Could not select embedded image \"%s\": %s\n",
 		      image->name, strerror ( rc ) );
 		return;
 	}