On Wednesday 10 October 2007 07:25, Alexander wrote:

...

"Please note that this is of special practical importance in the case of embedded devices, since the executable program(s) need to be somehow installed onto the device. If the user is not given a way to install his own (modified) versions of the program, he has no way of exercising his freedom to run modified versions of the program."

Agreed. That is what I want is just to run on your device modified version of Linux.

It occurs to me that Amstrad don't want to release the keys they've used to sign/encrypt their new code, however the new 5.1 bootloader won't accept unsigned/unenecrypted code, and therefore we get a sort of stalemate. How would both Amstrad and the open source community here feel about the following proposal? Amstrad provides a signed/encrypted (whatever is needed to get it to load onto a 5.1 device) copy of the 4.9 bootloader, so that it becomes possible to 'downgrade' a device to a state where we _can_ load our own open source code. That way Amstrad keeps its keys, but the devices which were released running Linux remain open for us to use as the GPL requires. Comments, people? Antony. -- It is against Google's terms of service for anyone under the age of 18 (in the UK, at least) to use the Google search system: "2.3 You may not use the Services and may not accept the Terms if you are not of legal age to form a binding contract with Google." http://www.google.com/accounts/TOS Please reply to the list; please don't CC me.

Antony Stone wrote: [...]

It occurs to me that Amstrad don't want to release the keys they've used to sign/encrypt their new code, however the new 5.1 bootloader won't accept unsigned/unenecrypted code, and therefore we get a sort of stalemate.

AIUI, the reason why Amstrad are doing this in the first place is to prevent people from buying up large numbers of emailers (which are sold at a loss, remember), reflashing them, and then selling them on. This is apparently fairly likely in eastern Europe. [...]

That way Amstrad keeps its keys, but the devices which were released running Linux remain open for us to use as the GPL requires.

Except the whole point of the exercise is to *close* the device... (And the GPL, v2 at least, *doesn't* require the devices be open. The exact phrasing is: “The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable.” PBL and the encryption keys are not covered by this. PBL because it's not GPLd, and the encryption keys because they're not an interface definition file or script.) What they might be more likely to go with is a mechanism for obtaining the key to an individual emailer --- either by paying them the difference in price between what it cost to build and what it's sold at (so that they don't end up out of pocket), or by just asking nicely; they don't seem to have a problem with small numbers of hobbyists. However, it's probably not possible to unlock an individual device. I wouldn't have thought they'd have per-machine keys. -- David Given dg@cowlark.com

Neil Stainton wrote:

Sorry if this has been covered before, but can't the NOR flash be read or rewritten simply by bit banging the memory bus via JTAG? The JTAG port on the POMAP5910JGDY is IEEE 1149 compliant which I take to mean that all the I/O on the device can be manually overidden.

Is the JTAG port brought out to a handy set of pads somewhere? If not, are the appropriate balls brought out to vias underneath the CPU?

Yup, this is perfectly possible, and I believe that there are some handy pads inside. (If you brick the device this is the only way of fixing it.) However, in order to reflash it, you have to take the lid off, do some soldering, and apply some technical knowledge --- which means that it's not going to be suitable for mass production. Reflashing using PBL, though, only requires plugging a jack in the back of the machine. -- David Given dg@cowlark.com

Matt Callow wrote: [...]

Do you know where the pads are? I've tried previously to find them - and failed. AFAIK, this information is not on the web anywhere

I found this info via Ralph's website: http://www.en4rab.dsl.pipex.com/ However, it does seem to be E2 and not E3. I could have sworn I saw someone report using JTAG on the E3, but I can't find it now either... the pads must be in there *somewhere*. -- David Given dg@cowlark.com

On Wednesday 10 October 2007 12:14, David Given wrote:

Neil Stainton wrote:

...

Sorry if this has been covered before, but can't the NOR flash be read or rewritten simply by bit banging the memory bus via JTAG? The JTAG port on the POMAP5910JGDY is IEEE 1149 compliant which I take to mean that all the I/O on the device can be manually overidden.

Is the JTAG port brought out to a handy set of pads somewhere? If not, are the appropriate balls brought out to vias underneath the CPU?

Yup, this is perfectly possible, and I believe that there are some handy pads inside. (If you brick the device this is the only way of fixing it.)

However, in order to reflash it, you have to take the lid off, do some soldering, and apply some technical knowledge --- which means that it's not going to be suitable for mass production. Reflashing using PBL, though, only requires plugging a jack in the back of the machine.

Yes, but considering that (as far as I know) we've never seen a retail unit already containing PBL 5.1 (this only happens when the machine gets poisoned by plugging it into a UK phone line), it means that: - anyone who wants to reprogram virgin devices en masse can do so using the jack socket on the back, talking to PBL 4.9 - anyone who wants to rejuvenate a used device which has been "upgraded" to 5.1 can do so with the once-off inconvenience of using the JTAG socket/pads I'm assuming of course that it's possible to reflash 4.9 into a device using the JTAG interface, although I've never attempted to do this (I've made sure none of my E3s get near a phone socket). Antony. -- I want to build a machine that will be proud of me. - Danny Hillis, creator of The Connection Machine Please reply to the list; please don't CC me.

Hi Antony,

How would both Amstrad and the open source community here feel about the following proposal?

Amstrad provides a signed/encrypted (whatever is needed to get it to load onto a 5.1 device) copy of the 4.9 bootloader, so that it becomes possible to 'downgrade' a device to a state where we _can_ load our own open source code.

That way Amstrad keeps its keys, but the devices which were released running Linux remain open for us to use as the GPL requires.

Comments, people?

Amstrad's aim is to lock down the device. The use of GPL software in a device sold at a subsidised price was an error on their part since the GPL allows me to alter the E3 and remove the part that earns Amstrad post-sales revenue whilst maintaining functionality. Given Amstrad's lack of compliance knowledge when I initially contacted them, and that they never included the license in the package, I think they were poorly advised by MontaVista and didn't do sufficient research themselves. To summarise the concern expressed privately to me: it's that 1,000 units can be picked up by some commercial outfit, e.g. from Russia, taken back there, and used to some completely end that earns Amstrad no revenue. Having put the key system in place, adding to their list of GPL violations, I doubt they'll release a downgrade that lets us circumvent it. Cheers, Ralph.