Move scripting overview from source tree to doxygen manual.

git-svn-id: svn://svn.berlios.de/openocd/trunk@1852 b42882b7-edfa-0310-969c-e2dbd0fdcd60

doc/manual/scripting.txt

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+/** @page scripting OpenOCD Scripting Overview
+
+@section What scripting will not do
+
+The scripting support is intended for developers of OpenOCD.
+It is not the intention that normal OpenOCD users will
+use tcl scripting extensively, write lots of clever scripts,
+or contribute back to OpenOCD. 
+
+Target scripts can contain new procedures that end users may
+tinker to their needs without really understanding tcl.
+
+Since end users are not expected to mess with the scripting
+language, the choice of language is not terribly important
+to those same end users.
+
+Jim Tcl was chosen as it was easy to integrate, works
+great in an embedded environment and Øyvind Harboe
+had experience with it.
+
+@section Uses of scripting
+
+Default implementation of procedures in tcl/procedures.tcl.
+
+- Polymorphic commands for target scripts.
+  - there will be added some commands in Tcl that the target
+    scripts can replace.
+  - produce <productionfile> <serialnumber>. Default implementation
+    is to ignore serial number and write a raw binary file
+    to beginning of first flash. Target script can dictate
+    file format and structure of serialnumber. Tcl allows
+    an argument to consist of e.g. a list so the structure of
+    the serial number is not limited to a single string.
+  - reset handling. Precise control of how srst, trst & 
+    tms is handled.
+- replace some parts of the current command line handler.
+  This is only to simplify the implementation of OpenOCD
+  and will have no externally visible consequences.
+  Tcl has an advantage in that it's syntax is backwards
+  compatible with the current OpenOCD syntax.
+- external scripting. Low level tcl functions will be defined
+  that return machine readable output. These low level tcl
+  functions constitute the tcl api. flash_banks is such
+  a low level tcl proc. "flash banks" is an example of
+  a command that has human readable output. The human 
+  readable output is expected to change inbetween versions
+  of OpenOCD. The output from flash_banks may not be
+  in the preferred form for the client. The client then
+  has two choices a) parse the output from flash_banks
+  or b) write a small piece of tcl to output the
+  flash_banks output to a more suitable form. The latter may
+  be simpler.
+  
+  
+@section External scripting
+
+The embedded Jim Tcl interpreter in OpenOCD is very limited
+compared to any full scale PC hosted scripting language.
+
+The goal is to keep the internal Jim Tcl interpreter as
+small as possible and allow any advanced scripting,
+especially scripting that interacts with the host,
+run on the host and talk to OpenOCD via the TCP/IP
+scripting connection.
+
+Another problem with Jim Tcl is that there is no debugger
+for it.
+
+With a bit of trickery it should be possible to run Jim
+Tcl scripts under a Tcl interpreter on a PC. The advantage
+would be that the Jim Tcl scripts could be debugged using
+a standard PC Tcl debugger.
+
+The rough idea is to write an unknown proc that sends
+unknown commands to OpenOCD.
+
+Basically a PC version of startup.tcl. Patches most
+gratefully accepted! :-)
+
+ */