From 93f2afa45f4cfcb8afd08dae5a17996dba5c7a9c Mon Sep 17 00:00:00 2001 From: David Brownell Date: Fri, 2 Jul 2010 16:45:28 -0400 Subject: initial "transport" framework This adds the guts of a transport framework with initialization, which should work with current JTAG-only configurations (tested with FT2232). Each debug adapter can declare the transports it supports, and exactly one transport is initialized. (with its commands) in any given OpenOCD session. * Define a new "struct transport with init hooks and a few "transport" subcommands to support it: "list" ... list the transports configured (just "jtag" for now) "select" ... makes the debug session use that transport "init" ... initializes the selected transport (internal) * "interface_transports" ... declares transports the current interface can support. (Some will do this from C code instead, when there are no hardware versioning (or other) issues to prevent it. Plus some FT2232 tweaks, including a few to streamline upcoming support for an SWD transport (initially for Luminary adapters). Eventually src/jtag should probably become src/transport, moving jtag-specific stuff to transport/jtag. Signed-off-by: David Brownell --- doc/openocd.texi | 44 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 43 insertions(+), 1 deletion(-) (limited to 'doc') diff --git a/doc/openocd.texi b/doc/openocd.texi index a3ca1247..a765727c 100644 --- a/doc/openocd.texi +++ b/doc/openocd.texi @@ -2096,6 +2096,14 @@ target. List the debug adapter drivers that have been built into the running copy of OpenOCD. @end deffn +@deffn Command {interface transports} transport_name+ +Specifies the transports supported by this debug adapter. +The adapter driver builds-in similar knowledge; use this only +when external configuration (such as jumpering) changes what +the hardware can support. +@end deffn + + @deffn Command {adapter_name} Returns the name of the debug adapter driver being used. @@ -2428,7 +2436,41 @@ Turn power switch to target on/off. No arguments: print status. @end deffn -@end deffn +@section Transport Configuration +As noted earlier, depending on the version of OpenOCD you use, +and the debug adapter you are using, +several transports may be available to +communicate with debug targets (or perhaps to program flash memory). +@deffn Command {transport list} +displays the names of the transports supported by this +version of OpenOCD. +@end deffn + +@deffn Command {transport select} transport_name +Select which of the supported transports to use in this OpenOCD session. +The transport must be supported by the debug adapter hardware and by the +version of OPenOCD you are using (including the adapter's driver). +No arguments: print selected transport.. +@end deffn + +@subsection JTAG Transport +JTAG is the original transport supported by OpenOCD, and most +of the OpenOCD commands support it. +JTAG transports expose a chain of one or more Test Access Points (TAPs), +each of which must be explicitly declared. +JTAG supports both debugging and boundary scan testing. +Flash programming support is built on top of debug support. +@subsection SWD ransport +SWD (Serial Wire Debug) is an ARM-specific transport which exposes one +Debug Access Point (DAP, which must be explicitly declared. +(SWD uses fewer signal wires than JTAG.) +SWD is debug-oriented, and does not support boundary scan testing. +Flash programming support is built on top of debug support. +(Some processors support both JTAG and SWD.) +@subsection SPI ransport +The Serial Peripheral Interface (SPI) is a general purpose transport +which uses four wire signaling. Some processors use it as part of a +solution for flash programming. @anchor{JTAG Speed} @section JTAG Speed -- cgit v1.2.3