General Question About Boot-up And Bricking

[D.C.]

Does anyone know where i can find info about how to build a JTag an set it up for use?

 

[KaosOverride]

Does anyone know where i can find info about how to build a JTag an set it up for use?

​

Do you read previous posts at the same thread? 2 posts above your's is one from myself with a link with COMPLETE INFO about building your homebrew JTAG + software for burning 1.1.0 UBOOT

Try! I wish you good luck restoring your blacky (I did!!!)

 

[D.C.]

Don't worry, I do read previous posts. But unfortunately I don't understand Spanish.. I'll have a look at it anyway.

 

[KaosOverride]

Don't worry, I do read previous posts. But unfortunately I don't understand Spanish.. I'll have a look at it anyway.

​

I wish the PNG scheme should be "universal" and you can understand and build it easy. Do not use the TXT scheme because the ARM pinout IS NOT the EXT port, is a generic JTAG for ARM... EXT conector can be easily used from the TVout if you consier to sacrify it!!

The "soft" is pretty easy to run, from JTAG KIT.zip use the exe to generate a bootdisk from windoze, boot the floppy and after some waiting you get a # root prompt

Plug the LPT port of the JTAG to the PC, and the EXT port to the GP2x, turn on the GP2x

then you type :

cd jtag

./jtagprobe

and you get the jtagprobe> prompt (also a MMSP2 detected! if the cable is working ok!!)

script reflash.sh

and just wait until done! appears.

At that stage of the restore procedure, the GP2x will start reflashing the UBOOT (Yes, you just upload a reflashing soft + the UBOOT as it's data... you don't upload the UBOOT in raw...)

It takes some time, but you are blind to this if you don't have a terminal software to attach to GP2x serial connector (which needs signal conversion to allow a PC to connect to it)

Also, because you are under linux with this bootdisk and IN CASE you got such serial conversor, you can quit jtagprobe when you see the Done! message and type cat /dev/ttyS0 (for COM1) and watch the progress (Notice that the progress has started before you have time to type the cat /dev/ttyS0)

Anyway, after Done! message, wait 3 minutes and switch off the GP2x, then on... And enjoy the pretty black booting screen

For a total NAND corruption, you need to restore first the UBOOT, then you need an SD card with GP2XKERNEL.IMG + GP2XFILES.IMG + Kernel especific pathes, then wait first to the Kernel restoring, then the filesystem restore and carefull after that... After filesystem restore, BOOT UP THE GP2X WITH THE SD OUT!!! Because GP2xFILES.IMG is not erased after correct reboot... (And you reflash at second time the filesystem). Then insert the SD and apply patch

Well, once you got the UBOOT working, the rest is to follow the "Unbricking Guide!" for kernel and filesystem restore

Enjoy!!

 

[edanuff]

Kaos, thanks for your writeup. I looked at the link you provided and I couldn't find the file JTAG KIT.zip, and I can read Spanish

 

[Epicenter]

Something like Gigabyte's "Dual BIOS" feature on their motherboards would be nice-- where if your BIOS is corrupted or you mis-flash it, you can restore it via software or a jumper. What we could really use is what most AWARD BIOS'es support, loading a BIOS image off a floppy (here, an SD card) automagically if the firmware (BIOS) is corrupted. Unfortunately that would require some hardware modification to the system, you couldn't just add it to the firmware (it's what'd get damaged in the first place!)

 

[Muncher666]

Kaos, thanks for your writeup. I looked at the link you provided and I couldn't find the file JTAG KIT.zip, and I can read Spanish

​

You have to register in the forums first. I don't really know spanish, but I could work out enough to fumble my way through the registration process.

I'll try and upload the file to the archive if anyone's interested.

KaosOverride, my electronics knowledge is limited, enough to wire up some simple pieces of work (I made a home made voltage regulator for my crappy power supply, for instance) but all I see on the circuit diagram are resistors, capacitors and diodes. Am I reading this wrong, or is that all there is to the JTAG interface box? I expected there to at least be some sort of interface chip.

Allan.

Allan.

 

[edanuff]

You have to register in the forums first.

Aha, that would explain it. It would be good if it was uploaded to the archive to make it easier for people in the future.

About your question about the circuit for the JTAG interface. The simple versions that you see circuits for on the net are basically translating the output of the PC's paralllel port. All the hard work is done in software on the PC, so that's why the circuit is that simple. Also, you can find pre-built ones pretty cheap as well, which you might want to consider. Just google for wiggler compatible jtag.

 

[White Demon]

Sort of on topic... can you insert a SD card after the GP2X has booted?

I think I remember reading here months ago that you can, but I can't remember for sure.

If you can, surely that would be the way to avoid bricking?

 

[iignotus]

Sort of on topic... can you insert a SD card after the GP2X has booted?

I think I remember reading here months ago that you can, but I can't remember for sure.

If you can, surely that would be the way to avoid bricking?

​

Yes, you can, and yes, that's what some people do.

 

[joyrider]

You have to register in the forums first.

Also, you can find pre-built ones pretty cheap as well, which you might want to consider. Just google for wiggler compatible jtag.

​

is this the right connector for the cable it says it's a arm jtag cable but i don't know if the cable connector would fit on the gp2x :

foto and info here : http://www.olimex.com/dev/arm-jtag.html
it's pretty cheap as well only about 20$ and they have distrubutors in diffrent countries even in belgium for me.

all i want to know is if it's the correct cable, i just might get one just in case something goes wrong

update:
hmm uses ARM's standard 2x10 pin JTAG connector , seems not to be it, i hope i never brake my gp2x when i get it or someone would have to built me a cable cause i have no clue about that shematic

i've uploaded the jtag kit to a seperate place, so u don't need to go through registering on the spanish board, u can get the kit from here http://users.pandora.be/IMS/gp2x/gp2x%20JTAG%20KIT.zip

 

[juliodm]

Does anyone know where i can find info about how to build a JTag an set it up for use?

​

Do you read previous posts at the same thread? 2 posts above your's is one from myself with a link with COMPLETE INFO about building your homebrew JTAG + software for burning 1.1.0 UBOOT

Try! I wish you good luck restoring your blacky (I did!!!)

Regarding this JTag cable.... I know nothing regarding this stuff so please forgive my ignorance.... I have a cable that fits into the EXT port on my brand new, freshly bricked GP2X. It is a cable I bought for my phone. It has a USB connection on one side, a box in the middle of it with a chip inside and a serial connector that, as I stated, fits the GP2X perfectly. The chip manufacturer is Prolific. I have a picture of it at,
http://jadium.com/pic.jpg.
Can this cable be used to do the JTAG thing? Remember that I haven't the foggiest idea what any of this stuff means. I just got a brand new GP2X on monday, come friday they release the 2.0 firmware, and thus ended my friendship with the GP2X.

Thanks again for any info.

 

[Muncher666]

Does anyone know where i can find info about how to build a JTag an set it up for use?

​

Do you read previous posts at the same thread? 2 posts above your's is one from myself with a link with COMPLETE INFO about building your homebrew JTAG + software for burning 1.1.0 UBOOT

Try! I wish you good luck restoring your blacky (I did!!!)

Regarding this JTag cable.... I know nothing regarding this stuff so please forgive my ignorance.... I have a cable that fits into the EXT port on my brand new, freshly bricked GP2X. It is a cable I bought for my phone. It has a USB connection on one side, a box in the middle of it with a chip inside and a serial connector that, as I stated, fits the GP2X perfectly. The chip manufacturer is Prolific. I have a picture of it at,
http://jadium.com/pic.jpg.
Can this cable be used to do the JTAG thing? Remember that I haven't the foggiest idea what any of this stuff means. I just got a brand new GP2X on monday, come friday they release the 2.0 firmware, and thus ended my friendship with the GP2X.

Thanks again for any info.

If you're at all handy with a soldering iron, you may be in luck.

Allan.

 

[juliodm]

Does anyone know where i can find info about how to build a JTag an set it up for use?

​

Do you read previous posts at the same thread? 2 posts above your's is one from myself with a link with COMPLETE INFO about building your homebrew JTAG + software for burning 1.1.0 UBOOT

Try! I wish you good luck restoring your blacky (I did!!!)

Regarding this JTag cable.... I know nothing regarding this stuff so please forgive my ignorance.... I have a cable that fits into the EXT port on my brand new, freshly bricked GP2X. It is a cable I bought for my phone. It has a USB connection on one side, a box in the middle of it with a chip inside and a serial connector that, as I stated, fits the GP2X perfectly. The chip manufacturer is Prolific. I have a picture of it at,
http://jadium.com/pic.jpg.
Can this cable be used to do the JTAG thing? Remember that I haven't the foggiest idea what any of this stuff means. I just got a brand new GP2X on monday, come friday they release the 2.0 firmware, and thus ended my friendship with the GP2X.

Thanks again for any info.

If you're at all handy with a soldering iron, you may be in luck.

Allan.

I had my engineers at work build the jtag cable illustrated in the jpg, this is what the console returned:
Jtag = Using port 0x378
JTAG interface reset.
Device ID..0x00000000
CPU Not Support!
#

I've tried it on many computers. Several at home and several at work. No luck as of yet on getting it to see the unit. Does anyone have any advice as to how to proceed?

 

[EvilDragon]

I had my engineers at work build the jtag cable illustrated in the jpg, this is what the console returned:
Jtag = Using port 0x378
JTAG interface reset.
Device ID..0x00000000
CPU Not Support!
#

I've tried it on many computers. Several at home and several at work. No luck as of yet on getting it to see the unit. Does anyone have any advice as to how to proceed?

This can have several causes:

1. Faulty cable (some wrong connections)
2. Wrong parallel port (check if your parallel port is set to 0x378 in Bios)
3. Batteries nigh empty or some other problems with the power source (i.e. PSU wrong polarity, wrong current, etc.)
4. gp2x totally broken (and thus can not be found). Had this a few times, however, only when the gp2x stopped working in the middle of a game or so.

 

[juliodm]

I had my engineers at work build the jtag cable illustrated in the jpg, this is what the console returned:
Jtag = Using port 0x378
JTAG interface reset.
Device ID..0x00000000
CPU Not Support!
#

I've tried it on many computers. Several at home and several at work. No luck as of yet on getting it to see the unit. Does anyone have any advice as to how to proceed?

This can have several causes:

1. Faulty cable (some wrong connections)
2. Wrong parallel port (check if your parallel port is set to 0x378 in Bios)
3. Batteries nigh empty or some other problems with the power source (i.e. PSU wrong polarity, wrong current, etc.)
4. gp2x totally broken (and thus can not be found). Had this a few times, however, only when the gp2x stopped working in the middle of a game or so.

You might be correct. I am using a power supply unit. The computer notices that the GP2X is connected because the address changes from Device ID..0x00000000 to Device ID..0xFFFFFFFF when the unit is not conected. Could that still mean something is wrong with the cable? I'm hoping it's the cable. I checked the bios, it states that the parallel port is runing on 0378. It is set to bidirectional, and has another setting set to 7 instead of 5. I tried changing the bidirectional to normal EPC and something else, I forget what it was, but none of them worked. I'm almost ready to give up and either break this thing or mail it to you EvilDragon.

 

[nubie]

EXT conector can be easily used from the TVout if you consier to sacrify it!!

Also, because you are under linux with this bootdisk and IN CASE you got such serial conversor, you can quit jtagprobe when you see the Done! message and type cat /dev/ttyS0 (for COM1) and watch the progress (Notice that the progress has started before you have time to type the cat /dev/ttyS0)

Anyway, after Done! message, wait 3 minutes and switch off the GP2x, then on... And enjoy the pretty black booting screen

For a total NAND corruption, you need to restore first the UBOOT, then you need an SD card with GP2XKERNEL.IMG + GP2XFILES.IMG + Kernel especific pathes, then wait first to the Kernel restoring, then the filesystem restore and carefull after that... After filesystem restore, BOOT UP THE GP2X WITH THE SD OUT!!! Because GP2xFILES.IMG is not erased after correct reboot...

I built my own serial convertor from a $5 Cellphone Cable for a Samsung e810 Serial Data cable (NOT USB) it is easy because the voltage converter is already soldered to PCB on the RS-232 port in that cable.

See the wiki on this write-up from somebody who built my interface too, http://wiki.gp2x.org/wiki/SamsungE810Cable

This cable also has all the pins on it so it is useful for a Jtag at the same time .

Would you need two computers to see the Serial Data? or just two shells on one PC?

Also, if I didn't have a uboot compatible SD card would this be useful for upgrading my uboot to a unbrickable/FW 2.0 compatible uboot?

If all of this is on a bootable floppy I really need to see this on the english wiki, It would be cool to have a unbricker for about $10 worth of parts . The peace of mind would be enormous.


Please do upload that file to the archive if you haven't already, thanks very much in advance.

 

[Epicenter]

Aren't the pins used for JTAG entirely different than those used on the device that cable was meant for? You should need to build a new cable based on the same EXT connector type, with the wires oriented in the proper fashion to match the way the EXT port orients the JTAG pins ...

 

[nubie]

Aren't the pins used for JTAG entirely different than those used on the device that cable was meant for? You should need to build a new cable based on the same EXT connector type, with the wires oriented in the proper fashion to match the way the EXT port orients the JTAG pins ...

I am going to assume you mean me.

In which case, wtf are you talking about?

Go here: http://wiki.gp2x.org/wiki/EXT_Port, look at the picture of the EXT port.


Notice that list under the picture on that link, you will see that the pins are named by the data that they carry.

Some carry Jtag signals, some carry serial data, some carry TV and sound signals, some are for the USB, and some are for Positive and Negative power.

The Samsung e810 data cable has 24 pins and plugs into the GP2X EXT port, all the pins go to all the contacts on the GP2X port.

What I meant in my previous post was that my cable is for the serial data like KaosOverride said might be useful.

I also pointed out that all the pins are on that connector, so we can use it as the Jtag plug at the same time by building the Jtag interface and connecting it to the right pins.

Edit, sorry I seem to be snapping at everyone today.

 

[EvilDragon]

You might be correct. I am using a power supply unit. The computer notices that the GP2X is connected because the address changes from Device ID..0x00000000 to Device ID..0xFFFFFFFF when the unit is not conected. Could that still mean something is wrong with the cable? I'm hoping it's the cable. I checked the bios, it states that the parallel port is runing on 0378. It is set to bidirectional, and has another setting set to 7 instead of 5. I tried changing the bidirectional to normal EPC and something else, I forget what it was, but none of them worked. I'm almost ready to give up and either break this thing or mail it to you EvilDragon.

For me it looks like a faulty cable.
Because ALL broken gp2x I had always had device ID 0xFFFFFFFFF.
As you get a 0x0000000, your computer is recognizing that there is something connected, however, it looks like it gets rubbish data.

This is the schematic I got from DignSys, if you want to check:

PL1 25wayD Male												 PL2 20wayIDC

PL1/17-25 <--------------+-------------------------+--+-----------<  PL2/4,6,8,
						 |						 |  |			  10,12,14,
						 |	AC244		  200nF =  = 4.7uF		16,18,20
						 | +------------+  Vcc	 |  |
		 TDI		  0v +-| 1	   20 |-+--------+--+-----------<  PL2/1,2
PL1/5  >-------------------| 2	   19 |-+
		 TMS			   | 3	   18 |-----XXXX---------------->  PL2/5
PL1/3  >-------------------| 4	   17 |	 51R	 
		 TCLK			  | 5	   16 |-----XXXX---------------->  PL2/7
PL1/4  >-------------------| 6	   15 |	 51R
						   | 7	   14 |-----XXXX---------------->  PL2/9
					  +----| 8	   13 |	 51R
					  |	| 9	   12 |-----XXXX---+
					  |  +-| 10	  11 |	 51R	|
					  |  | +------------+			|
					  |  V 0v						|
					  +------------------------------------------<   PL2/13
		 TDO										 |
PL1/11 <---------------------------------------------+


							DTC114   /-------xxxx----------------<   PL2/15
		 RST			10k	   | /		51R
PL1/2  >----------------XXXX--+---|<
							  |   | \
							  X	  V
						 47k  X	  |  
							  X	  |
							  |	  |
							  V 0v   V