config: add init_targets proc that is executed just before init

this allows configuration scripts to export a init_targets proc
rather than setting up the target directly.

This allows for new conventions in how to set up target vs. board
script and how to transfer default settings between board and
target scripts.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

src/openocd.c

@@ -340,6 +340,10 @@ int openocd_main(int argc, char *argv[])
 	if (ERROR_OK != ret)
 		return EXIT_FAILURE;
 
+	ret = command_run_line(cmd_ctx, "init_targets");
+	if (ERROR_OK != ret)
+		ret = EXIT_FAILURE;
+
 	if (init_at_startup)
 	{
 		ret = command_run_line(cmd_ctx, "init");

src/target/startup.tcl

@@ -151,3 +151,11 @@ proc armv4_5 params {
 	echo "DEPRECATED! use 'arm $params' not 'armv4_5 $params'"
 	arm $params
 }
+
+# Target/chain configuration scripts can either execute commands directly 
+# or define a procedure which is executed once all configuration 
+# scripts have completed.
+#
+# By default(classic) the config scripts will set up the target configuration
+proc init_targets {} {
+}