src/jtag/transport.h

   1 /*
   2  * Copyright (c) 2010 by David Brownell
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software Foundation,
  16  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #include "helper/command.h"
  20
  21 /**
  22  * Wrapper for transport lifecycle operations.
  23  *
  24  * OpenOCD talks to targets through some kind of debugging
  25  * or programming adapter, using some protocol that probably
  26  * has target-specific aspects.
  27  *
  28  * A "transport" reflects electrical protocol to the target,
  29  * e..g jtag, swd, spi, uart, ... NOT the messaging protocols
  30  * layered over it (e.g. JTAG has eICE, CoreSight, Nexus, OnCE,
  31  * and more).
  32  *
  33  * In addition to the lifecycle operations packaged by this
  34  * structure, a transport also involves  an interface supported
  35  * by debug adapters and used by components such as debug targets.
  36  * For non-debug transports,  there may be interfaces used to
  37  * write to flash chips.
  38  */
  39 struct transport {
  40         /**
  41          * Each transport has a unique name, used to select it
  42          * from among the alternatives.  Examples might include
  43          * "jtag", * "swd", "AVR_ISP" and more.
  44          */
  45         const char *name;
  46
  47         /**
  48          * When a transport is selected, this method registers
  49          * its commands and activates the transport (e.g. resets
  50          * the link).
  51          *
  52          * After those commands are registered, they will often
  53          * be used for further configuration of the debug link.
  54          */
  55         int (*select)(struct command_context *ctx);
  56
  57         /**
  58          * server startup uses this method to validate transport
  59          * configuration.  (For example, with JTAG this interrogates
  60          * the scan chain against the list of expected TAPs.)
  61          */
  62         int (*init)(struct command_context *ctx);
  63
  64         /**
  65          * Transports are stored in a singly linked list.
  66          */
  67         struct transport *next;
  68 };
  69
  70 int transport_register(struct transport *new_transport);
  71
  72 struct transport *get_current_transport(void);
  73
  74 int transport_register_commands(struct command_context *ctx);
  75
  76 COMMAND_HELPER(transport_list_parse, char ***vector);
  77
  78 int allow_transports(struct command_context *ctx, const char **vector);
  79
  80 bool transports_are_declared(void);