--- a/packages/hal/arm/at91/var/current/ChangeLog
+++ b/packages/hal/arm/at91/var/current/ChangeLog
@@ -1,3 +1,15 @@
+2008-07-12  Andrew Lunn  <andrew.lunn@ascom.ch>
+
+	* src/hal_diag_dcc.{ch}
+	* src/hal_diag.c
+	* src/hal_diag_dbg.c
+	* cdl/hal_arm_at91.cdl: Add support for DCC, ie the Debug
+	Communications Channel, which is part of JTAG core of AT91 and
+	most ARM processors. JTAG devices often make this available via a
+	TCP port which can be accessed via telnet. NOTE: Only output to
+	DCC has been tested via diag_printf. Code exists for input, but it
+	has not been tested.
+	
 2007-03-05  Andrew Lunn <andrew.lunn@ascom.ch>
 
 	* include/var_io.h: Fix a few typos pointed out by

--- a/packages/hal/arm/at91/var/current/cdl/hal_arm_at91.cdl
+++ b/packages/hal/arm/at91/var/current/cdl/hal_arm_at91.cdl
@@ -169,4 +169,27 @@ cdl_package CYGPKG_HAL_ARM_AT91 {
             The driver for using the UARTS will be compiled in the
             varient HAL when this option is enabled."
     }
-}
+
+    cdl_component CYGBLD_HAL_ARM_AT91_DCC {
+        display       "Enable the use of the DCC for debug output"
+        flavor        bool
+        default_value 0
+        compile       hal_diag_dcc.c
+        description   "
+            A <serial> driver will be compiled and inserted into the
+            vector table which does I/O via the DCC. The DCC is part of
+            the JTAG interface and some JTAG devices made this interface
+            available via telnet etc."
+        
+        cdl_option CYGBLD_HAL_ARM_AT91_DCC_CHANNEL {   
+            display       "Channel the DCC port should use in the VV table"
+            flavor        data
+            default_value 2
+            description   "
+                The DCC driver has to be registered in the VV table of
+                drivers. This option determines which entry in the
+                table it will take. The default value will overwride
+                the first serial port. "
+        }
+    }
+}
\ No newline at end of file

--- a/packages/hal/arm/at91/var/current/src/hal_diag.c
+++ b/packages/hal/arm/at91/var/current/src/hal_diag.c
@@ -65,6 +65,7 @@
 
 #include <cyg/hal/var_io.h>             // USART registers
 
+#include "hal_diag_dcc.h"               // DCC initialization file
 //-----------------------------------------------------------------------------
 typedef struct {
     cyg_uint8* base;
@@ -357,6 +358,10 @@ cyg_hal_plf_comms_init(void)
     initialized = 1;
 
     cyg_hal_plf_serial_init();
+
+#ifdef CYGBLD_HAL_ARM_AT91_DCC
+    cyg_hal_plf_dcc_init(CYGBLD_HAL_ARM_AT91_DCC_CHANNEL);
+#endif
 }
 
 void

--- a/packages/hal/arm/at91/var/current/src/hal_diag_dbg.c
+++ b/packages/hal/arm/at91/var/current/src/hal_diag_dbg.c
@@ -66,6 +66,7 @@
 
 #include <cyg/hal/var_io.h>             // Device registers
 
+#include "hal_diag_dcc.h"               // DCC initialization file
 //-----------------------------------------------------------------------------
 typedef struct {
     cyg_uint8* base;
@@ -331,6 +332,10 @@ cyg_hal_plf_comms_init(void)
     initialized = 1;
 
     cyg_hal_plf_serial_init();
+
+#ifdef CYGBLD_HAL_ARM_AT91_DCC
+    cyg_hal_plf_dcc_init(CYGBLD_HAL_ARM_AT91_DCC_CHANNEL);
+#endif
 }
 
 void

new file mode 100644
--- /dev/null
+++ b/packages/hal/arm/at91/var/current/src/hal_diag_dcc.c
@@ -0,0 +1,211 @@
+/*=============================================================================
+//
+//      hal_diag_dcc.c
+//
+//      HAL diagnostic output via the DCC interface.
+//
+//=============================================================================
+//####ECOSGPLCOPYRIGHTBEGIN####
+// -------------------------------------------
+// This file is part of eCos, the Embedded Configurable Operating System.
+// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
+// Copyright (C) 2008 FSF
+//
+// eCos is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 2 or (at your option) any later version.
+//
+// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with eCos; if not, write to the Free Software Foundation, Inc.,
+// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+//
+// As a special exception, if other files instantiate templates or use macros
+// or inline functions from this file, or you compile this file and link it
+// with other works to produce a work based on this file, this file does not
+// by itself cause the resulting work to be covered by the GNU General Public
+// License. However the source code for this file must still be made available
+// in accordance with section (3) of the GNU General Public License.
+//
+// This exception does not invalidate any other reasons why a work based on
+// this file might be covered by the GNU General Public License.
+//
+// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
+// at http://sources.redhat.com/ecos/ecos-license/
+// -------------------------------------------
+//####ECOSGPLCOPYRIGHTEND####
+//=============================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s):   Andrew Lunn
+// Contributors:jskov, gthomas
+// Date:        2008-06-15
+// Purpose:     HAL diagnostic output via DCC.
+// Description: Implementations of HAL diagnostic output support.
+//
+//####DESCRIPTIONEND####
+//
+//===========================================================================*/
+
+#include <pkgconf/hal.h>
+#include CYGBLD_HAL_PLATFORM_H
+
+#include <cyg/infra/cyg_type.h>         // base types
+
+#include <cyg/hal/hal_arch.h>           // SAVE/RESTORE GP macros
+#include <cyg/hal/hal_io.h>             // IO macros
+#include <cyg/hal/hal_if.h>             // interface API
+#include <cyg/hal/hal_intr.h>           // HAL_ENABLE/MASK/UNMASK_INTERRUPTS
+#include <cyg/hal/hal_misc.h>           // Helper functions
+#include <cyg/hal/hal_diag.h>
+
+#define DCC_TX_BUSY 2
+#define DCC_RX_READY 1
+
+//-----------------------------------------------------------------------------
+
+static void
+cyg_hal_plf_dcc_putc(void * __ch_data, char ch)
+{
+  unsigned int status;
+  CYG_UNUSED_PARAM(void *, __ch_data);
+
+  CYGARC_HAL_SAVE_GP();
+  
+  do {
+    __asm__ volatile ( "mrc p14,0, %0, c0, c0\n" : "=r" (status));
+  } while ( status & DCC_TX_BUSY );
+  __asm__( "mcr p14,0, %0, c1, c0\n" : : "r" (ch));
+  
+  CYGARC_HAL_RESTORE_GP();
+}
+
+static cyg_bool
+cyg_hal_plf_dcc_getc_nonblock(cyg_uint8* ch)
+{
+  cyg_uint32 status;
+  cyg_uint32 c;
+  
+  __asm__( "mrc p14,0, %0, c0, c0\n" : "=r" (status));
+  
+  if (status & DCC_RX_READY) {
+    __asm__( "mrc p14,0, %0, c1, c0\n" : "=r" (c));
+    *ch = (char )c;
+    return true;
+  } else 
+    return false;
+}
+
+static cyg_uint8
+cyg_hal_plf_dcc_getc(void* __ch_data)
+{
+  cyg_uint8 ch;
+  CYG_UNUSED_PARAM(void *, __ch_data);
+  CYGARC_HAL_SAVE_GP();
+  
+  while(!cyg_hal_plf_dcc_getc_nonblock(&ch));
+  
+  CYGARC_HAL_RESTORE_GP();
+  return ch;
+}
+
+static void
+cyg_hal_plf_dcc_write(void* __ch_data, const cyg_uint8* __buf, 
+                      cyg_uint32 __len)
+{
+  CYG_UNUSED_PARAM(void *, __ch_data);
+  CYGARC_HAL_SAVE_GP();
+  
+  while(__len-- > 0)
+    cyg_hal_plf_dcc_putc(NULL, *__buf++);
+  
+  CYGARC_HAL_RESTORE_GP();
+}
+
+static void
+cyg_hal_plf_dcc_read(void* __ch_data, cyg_uint8* __buf, cyg_uint32 __len)
+{
+  CYG_UNUSED_PARAM(void *, __ch_data);
+  CYGARC_HAL_SAVE_GP();
+  
+  while(__len-- > 0)
+    *__buf++ = cyg_hal_plf_dcc_getc(NULL);
+  
+  CYGARC_HAL_RESTORE_GP();
+}
+
+static cyg_bool
+cyg_hal_plf_dcc_getc_timeout(void* __ch_data, cyg_uint8* ch)
+{
+  int delay_count;
+  cyg_bool res;
+  CYG_UNUSED_PARAM(void *, __ch_data);
+
+  CYGARC_HAL_SAVE_GP();
+
+  delay_count = 100010; // delay in .1 ms steps
+
+  for(;;) {
+    res = cyg_hal_plf_dcc_getc_nonblock(ch);
+    if (res || 0 == delay_count--)
+      break;
+    
+    CYGACC_CALL_IF_DELAY_US(100);
+  }
+  
+  CYGARC_HAL_RESTORE_GP();
+  return res;
+}
+
+static int
+cyg_hal_plf_dcc_control(void *__ch_data, __comm_control_cmd_t __func, ...)
+{
+  CYG_UNUSED_PARAM(void *, __ch_data);
+  CYG_UNUSED_PARAM(__comm_control_cmd_t, __func);
+  
+  return 0;
+}
+
+static void
+cyg_hal_plf_dcc_register(const int channel)
+{
+  hal_virtual_comm_table_t* comm;
+  int cur;
+  
+  cur = CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);
+  // Setup procs in the vector table
+  
+  CYGACC_CALL_IF_SET_CONSOLE_COMM(channel);
+  comm = CYGACC_CALL_IF_CONSOLE_PROCS();
+  CYGACC_COMM_IF_CH_DATA_SET(*comm, NULL);
+  CYGACC_COMM_IF_WRITE_SET(*comm, cyg_hal_plf_dcc_write);
+  CYGACC_COMM_IF_READ_SET(*comm, cyg_hal_plf_dcc_read);
+  CYGACC_COMM_IF_PUTC_SET(*comm, cyg_hal_plf_dcc_putc);
+  CYGACC_COMM_IF_GETC_SET(*comm, cyg_hal_plf_dcc_getc);
+  CYGACC_COMM_IF_CONTROL_SET(*comm, cyg_hal_plf_dcc_control);
+  CYGACC_COMM_IF_DBG_ISR_SET(*comm, NULL);
+  CYGACC_COMM_IF_GETC_TIMEOUT_SET(*comm, cyg_hal_plf_dcc_getc_timeout);
+
+  // Restore to original console.
+  CYGACC_CALL_IF_SET_CONSOLE_COMM(cur);
+}
+
+void
+cyg_hal_plf_dcc_init(const int channel)
+{
+  static int initialized = 0;
+  
+  if (initialized)
+    return;
+  
+  initialized = 1;
+  
+  cyg_hal_plf_dcc_register(channel);
+}
+
+//-----------------------------------------------------------------------------
+// End of hal_diag_dcc.c

new file mode 100644
--- /dev/null
+++ b/packages/hal/arm/at91/var/current/src/hal_diag_dcc.h
@@ -0,0 +1,60 @@
+#ifndef CYGONCE_HAL_DIAG_DCC_H
+#define CYGONCE_HAL_DIAG_DCC_H
+
+//=============================================================================
+//
+//      hal_diag_dcc.h
+//
+//      HAL Support for Kernel Diagnostic Routines via DCC
+//
+//=============================================================================
+//####ECOSGPLCOPYRIGHTBEGIN####
+// -------------------------------------------
+// This file is part of eCos, the Embedded Configurable Operating System.
+// Copyright (C) 2008 FSF.
+//
+// eCos is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 2 or (at your option) any later version.
+//
+// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with eCos; if not, write to the Free Software Foundation, Inc.,
+// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+//
+// As a special exception, if other files instantiate templates or use macros
+// or inline functions from this file, or you compile this file and link it
+// with other works to produce a work based on this file, this file does not
+// by itself cause the resulting work to be covered by the GNU General Public
+// License. However the source code for this file must still be made available
+// in accordance with section (3) of the GNU General Public License.
+//
+// This exception does not invalidate any other reasons why a work based on
+// this file might be covered by the GNU General Public License.
+//
+// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
+// at http://sources.redhat.com/ecos/ecos-license/
+// -------------------------------------------
+//####ECOSGPLCOPYRIGHTEND####
+//=============================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s):   asl
+// Contributors:
+// Date:        2008-06-15
+// Purpose:     HAL Support for Kernel Diagnostic Routines via DCC.
+// Description: Diagnostic routines for use during kernel development.
+// Usage:       #include "hal_diag_dcc.h"
+//
+//####DESCRIPTIONEND####
+//
+//=============================================================================
+
+externC void cyg_hal_plf_dcc_init(const int channel);
+
+#endif
+