EJTAG - Revision history

Kthurow at 03:13, 11 September 2010

2010-09-11T03:13:23Z

Jpintozz: /* Probes */

2009-08-13T19:32:38Z

Probes

Agember at 20:23, 23 May 2008

2008-05-23T20:23:36Z

Jpicotte at 15:43, 4 October 2007

2007-10-04T15:43:01Z

Jpicotte at 15:34, 4 October 2007

2007-10-04T15:34:58Z

Jpicotte at 21:49, 24 July 2007

2007-07-24T21:49:24Z

Jpicotte: /* Debugging */

2007-07-15T16:24:21Z

Debugging

Jpicotte: /* Debugging */

2007-07-15T16:23:04Z

Debugging

Jpicotte at 22:27, 28 June 2007

2007-06-28T22:27:30Z

Phinze: /* Debugging */ separate paragraphs

2007-06-03T10:33:08Z

Debugging: separate paragraphs

@@ Line 9: / Line 9: @@
 == Debugging ==
-Attempting to use GNU debugger: http://www.gnu.org/software/gdb.  GDP uses its own Remote Serial Protocol (RDB) to communicate to remote targets.  This protocol could be used to communicate with the XINU backends through the current serial connection.  Although, this would require additions to XINU: communication with the GDB host; altering of exception handler to allow GDB to take control of target processor.
+Attempting to use GNU debugger: http://www.gnu.org/software/gdb.  GDB uses its own Remote Serial Protocol (RDB) to communicate to remote targets.  This protocol could be used to communicate with the XINU backends through the current serial connection.  Although, this would require additions to XINU: communication with the GDB host; altering of exception handler to allow GDB to take control of target processor.
 The use of the EJTAG port on the WRT54-series routers gives the user hardware control of the processor, avoiding the need for strategically placed breakpoints and XINU interrupt subsystem modification.  Additionally, requests by the debugger for specicfic data can be aquired directly from registers.  The trick to this operation is software that can interpret commands from RDB into EJTAG signals to be sent through the host parallel port, and vice-versa.  An implementation of this interpreter can be found at http://www.totalembedded.com/open_source/jtag/mips32_ejtag.php.

@@ Line 28: / Line 28: @@
 [[Image:Wiggler.png|thumb|700px|center|"wiggler" clone from OpenWRT]]
 [[Image:JTAGunbuffered.png|thumb|400px|center|unbuffered cable from OpenWRT; used by de-brick utility]]
 == See also ==
 * [[EJTAG ID Codes and Implementation Registers]]

← Older revision		Revision as of 20:23, 23 May 2008
Line 29:		Line 29:
	[[Image:JTAGunbuffered.png\|thumb\|400px\|center\|unbuffered cable from OpenWRT; used by de-brick utility]]		[[Image:JTAGunbuffered.png\|thumb\|400px\|center\|unbuffered cable from OpenWRT; used by de-brick utility]]

−	~~Return to~~ [[~~Summer 2007~~]]	+	== See also ==
		+	* [[EJTAG ID Codes and Implementation Registers]]

@@ Line 7: / Line 7: @@
 ** direct writing to flash for firmware updates (and de-bricking)
 == Debugging ==
@@ Line 13: / Line 12: @@
 The use of the EJTAG port on the WRT54-series routers gives the user hardware control of the processor, avoiding the need for strategically placed breakpoints and XINU interrupt subsystem modification.  Additionally, requests by the debugger for specicfic data can be aquired directly from registers.  The trick to this operation is software that can interpret commands from RDB into EJTAG signals to be sent through the host parallel port, and vice-versa.  An implementation of this interpreter can be found at http://www.totalembedded.com/open_source/jtag/mips32_ejtag.php.
@@ Line 22: / Line 26: @@
 [[Image:Te_jtag_cable.png|thumb|900px|center|Total Embedded buffered cable]]
-[[Image:Wiggler.png|thumb|600px|center|"wiggler" clone from OpenWRT]]
+[[Image:Wiggler.png|thumb|700px|center|"wiggler" clone from OpenWRT]]
-[[Image:JTAGunbuffered.png|thumb|500px|center|unbuffered cable from OpenWRT; used by de-brick utility]]
+[[Image:JTAGunbuffered.png|thumb|400px|center|unbuffered cable from OpenWRT; used by de-brick utility]]
 Return to [[Summer 2007]]

@@ Line 23: / Line 23: @@
 [[Image:Te_jtag_cable.png|thumb|900px|center|Total Embedded buffered cable]]
 [[Image:Wiggler.png|thumb|600px|center|"wiggler" clone from OpenWRT]]
-[[Image:JTAGunbuffered.png|thumb|700px|center|unbuffered cable from OpenWRT; used by de-brick utility]]
+[[Image:JTAGunbuffered.png|thumb|500px|center|unbuffered cable from OpenWRT; used by de-brick utility]]
 Return to [[Summer 2007]]

@@ Line 13: / Line 13: @@
 The use of the EJTAG port on the WRT54-series routers gives the user hardware control of the processor, avoiding the need for strategically placed breakpoints and XINU interrupt subsystem modification.  Additionally, requests by the debugger for specicfic data can be aquired directly from registers.  The trick to this operation is software that can interpret commands from RDB into EJTAG signals to be sent through the host parallel port, and vice-versa.  An implementation of this interpreter can be found at http://www.totalembedded.com/open_source/jtag/mips32_ejtag.php.
-Note that the unbuffered cable at the bottom of this page is only functional in writing to the Test Access Port.  It does not read data back from the port.
+Note that the unbuffered cable at the bottom of this page is only proven functional in writing to the Test Access Port.  It may not read data back from the target device.
 [[Image:Te_jtag_cable.png|thumb|900px|center|Total Embedded buffered cable]]

← Older revision		Revision as of 22:27, 28 June 2007
Line 12:		Line 12:

	The use of the EJTAG port on the WRT54-series routers gives the user hardware control of the processor, avoiding the need for strategically placed breakpoints and XINU interrupt subsystem modification. Additionally, requests by the debugger for specicfic data can be aquired directly from registers. The trick to this operation is software that can interpret commands from RDB into EJTAG signals to be sent through the host parallel port, and vice-versa. An implementation of this interpreter can be found at http://www.totalembedded.com/open_source/jtag/mips32_ejtag.php.		The use of the EJTAG port on the WRT54-series routers gives the user hardware control of the processor, avoiding the need for strategically placed breakpoints and XINU interrupt subsystem modification. Additionally, requests by the debugger for specicfic data can be aquired directly from registers. The trick to this operation is software that can interpret commands from RDB into EJTAG signals to be sent through the host parallel port, and vice-versa. An implementation of this interpreter can be found at http://www.totalembedded.com/open_source/jtag/mips32_ejtag.php.
		+
		+	Note that the unbuffered cable at the bottom of this page is only functional in writing to the Test Access Port. It does not read data back from the port.

	[[Image:Te_jtag_cable.png\|thumb\|900px\|center\|Total Embedded buffered cable]]		[[Image:Te_jtag_cable.png\|thumb\|900px\|center\|Total Embedded buffered cable]]