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Post by Spanner on Apr 18, 2019 10:12:13 GMT
Edward Robbins Tue, 26 Jun 2012 16:13:02 -0700
Hello e3 hackers,
I just received an e3, which to start with I'd just like to get a kernel to boot on (not quite sure what I'll do with it yet - but that will come later).
The guy that gave it to me me said it had been in storage for some time, so fingers crossed that it has not been updated. I don't know yet because I haven't got a compatible PSU yet!
If I understand correctly it's the proprietary bootloader on the 128Kb NOR flash that may have been updated making it difficult to hack? Would it be possible to get around this by flashing manually (using an AVR or similar?) If so would anyone be able to supply the correct binary image for the flash?
Assuming I can pass this hurdle, what is the shape of linux support for this now? I see from reading the mailing list that the late 2.6 series worked fine... how about 3.x? How about defconfigs with full (or as much as possible) hardware support? I am happy cross compiling a kernel... I guess I can use any old ARM cross compiler?
What exactly is the boot process and how does this limit the size of the kernel image? There's a way to get uboot on there - how can I do this? Does the kernel always need to be sent over serial?
Sorry for all the questions, but without reading the entire mailing list there doesn't seem to be an easy way to find answers!
Thanks, Ed
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Post by Spanner on Apr 18, 2019 10:12:51 GMT
Edward Robbins Tue, 26 Jun 2012 16:10:16 -0700
Hmm... actually programming the AT49LV1024 looks to be a pain in the butt, so I guess if it has PBL 5.1 I am screwed.
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Post by Spanner on Apr 18, 2019 10:13:33 GMT
Edward Robbins Tue, 26 Jun 2012 16:18:27 -0700
Sorry for 3rd email...
Using a 9V supply the emailer appears to start - email and voice lights flash, then after some time the power light comes on when I press power, and camera light comes on when I then press video, but the LCD does not come on. So I suspect that amstrad were being cheap in choosing such a high voltage PSU - because they didn't want to include a backlight inverter to boost the voltage for the LCD backlight. I thus further suspect that I can still talk to the serial port without the full voltage input... so if I build a cable, is there a way I can tell which PBL I have from the serial output?
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Post by Spanner on Apr 18, 2019 10:14:21 GMT
Antony Stone Tue, 26 Jun 2012 16:59:25 -0700 On Wednesday 27 June 2012 at 00:17, Edward Robbins wrote: > Sorry for 3rd email... > > Using a 9V supply the emailer appears to start - email and voice lights > flash, then after some time the power light comes on when I press power, > and camera light comes on when I then press video, but the LCD does not > come on. So I suspect that amstrad were being cheap in choosing such a high > voltage PSU - because they didn't want to include a backlight inverter to > boost the voltage for the LCD backlight. I thus further suspect that I can > still talk to the serial port without the full voltage input... so if I > build a cable, is there a way I can tell which PBL I have from the serial > output? See the first line of www.earth.li/%7Enoodles/files/delta.boot (linked from www.earth.li/~noodles/hardware-e3.html). Hope this helps, Antony. -- All generalisations are inaccurate.
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Post by Spanner on Apr 18, 2019 10:14:49 GMT
Janusz Krzysztofik Wed, 27 Jun 2012 13:46:25 -0700
On Tue, 26 Jun 2012 23:45:19 Edward Robbins wrote: > > Assuming I can pass this hurdle, what is the shape of linux support for > this now? I see from reading the mailing list that the late 2.6 series > worked fine... how about 3.x?
Hi, This won't help you with your PBL 5.1, but...
I'm still trying to do my best to keep this machine supported by subsequent kernel versions, actually running linux-3.4 on mine. Nothing new here since a few releases back, except for smartcard pins available as GPIO, ready for being driven from userspace over the /sys/ API. Perhaps someone ever finds some spare time to write a "driver" for it.
> How about defconfigs with full (or as much as > possible) hardware support?
The one I posted a few months ago generally still works for me, please examine the list archives.
> I am happy cross compiling a kernel... I guess > I can use any old ARM cross compiler? > > What exactly is the boot process and how does this limit the size of the > kernel image? There's a way to get uboot on there - how can I do this? Does > the kernel always need to be sent over serial?
I use the old install tools, ramdisk and procedure published in 2006. Works with new kernels built with my defconfig.
Thanks, Janusz
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Post by Spanner on Apr 18, 2019 10:15:15 GMT
Aaro Koskinen Fri, 06 Jul 2012 11:56:31 -0700
Hi,
On Wed, Jun 27, 2012 at 09:52:46PM +0200, Janusz Krzysztofik wrote: > > I am happy cross compiling a kernel... I guess > > I can use any old ARM cross compiler? > > > > What exactly is the boot process and how does this limit the size of the > > kernel image? There's a way to get uboot on there - how can I do this? Does > > the kernel always need to be sent over serial? > > I use the old install tools, ramdisk and procedure published in 2006. > Works with new kernels built with my defconfig.
I'm using modified !LDR that loads and boots the kernel and initramfs directly from NAND (they can also be sent over the the serial line). So you don't really need U-boot at all (unless you need some fancy features...).
Once you have booted succesfully, you can update the kernel just with nandwrite. You need to send it over the serial only when booting for the first time, or when you have flashed a kernel that does not work.
The NAND partitioning is static (hardcoded in the kernel). If I remember correctly, the kernel partition is limited to 3.5 MB. My !LDR loads the initramfs from "file system" partition which is tens of megabytes. In practice these size limitations are not a problem.
For the userspace, you can use e.g. the latest Debian rootfs on USB disk.
A.
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Post by Spanner on Apr 18, 2019 10:16:09 GMT
Edward Robbins Wed, 27 Jun 2012 10:40:47 -0700 Thanks, that helped. I just got it to output serial... and it's PBL 5.1. I guess that means it's basically a brick then? Any plausible way around? On Wed, Jun 27, 2012 at 9:06 AM, Antony Stone < antony.st...@e3.open.source.it> wrote: > On Wednesday 27 June 2012 at 00:17, Edward Robbins wrote: > > > Sorry for 3rd email... > > > > Using a 9V supply the emailer appears to start - email and voice lights > > flash, then after some time the power light comes on when I press power, > > and camera light comes on when I then press video, but the LCD does not > > come on. So I suspect that amstrad were being cheap in choosing such a > high > > voltage PSU - because they didn't want to include a backlight inverter to > > boost the voltage for the LCD backlight. I thus further suspect that I > can > > still talk to the serial port without the full voltage input... so if I > > build a cable, is there a way I can tell which PBL I have from the serial > > output? > > See the first line of www.earth.li/%7Enoodles/files/delta.boot(linked> from www.earth.li/~noodles/hardware-e3.html). > > Hope this helps, > > > Antony. > > -- > All generalisations are inaccurate. > -- > I'm not impossible, just highly implausible. > > Please reply to the > list; > please don't CC > me.
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Post by Spanner on Apr 18, 2019 10:17:06 GMT
Antony Stone Wed, 27 Jun 2012 11:20:13 -0700 On Wednesday 27 June 2012 at 18:40, Edward Robbins wrote: > Thanks, that helped. > > I just got it to output serial... and it's PBL 5.1. > > I guess that means it's basically a brick then? Any plausible way around? I personally know of no way to reflash it once it's got 5.1, but I'm not exactly an expert around here. Others may well be better-informed than I am. I just hope there are some others still around here, though - I guess that since you only just got your E3, you only just joined the mailing list - so you probably don't know that the previous posting before yours on Tuesday this week was Sunday December 11th 2011.... I hope someone can give you a better answer. > On Wed, Jun 27, 2012 at 9:06 AM, Antony Stone wrote: > > On Wednesday 27 June 2012 at 00:17, Edward Robbins wrote: > > > > > ... so if I build a cable, is there a way I can tell which PBL I have > > > from the serial output? > > > > See the first line of > > www.earth.li/%7Enoodles/files/delta.boot (linked from > > www.earth.li/~noodles/hardware-e3.html). > > > > Hope this helps, > > > > > > Antony. -- The lottery is a tax for people who can't do maths.
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Post by Spanner on Apr 18, 2019 10:17:49 GMT
Ralph Corderoy Thu, 28 Jun 2012 05:58:13 -0700
Hi,
Antony Stone wrote: > Edward Robbins wrote: > > I guess that means it's basically a brick then? Any plausible way > > around? > > I personally know of no way to reflash it once it's got 5.1, but I'm > not exactly an expert around here. Others may well be better-informed > than I am.
I suppose JTAG using the exposed pads on the circuit board, how the ROM's contents were obtained originally IIRC, might be a complex option...
Is it correct that no revenue is now made from the Emailer family; that the premium rate numbers have been closed, etc., and whoever bought the relevant part of Amstrad has no interest in operating it any more? If so, could an approach to them to make available, e.g. signing key, for the benefit of those that want to tinker? No skin off their nose now and if the right person is reached it may work, what with the increased prominence of the Maker movement, etc.
Cheers, Ralph.
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Post by Spanner on Apr 18, 2019 10:39:18 GMT
Edward Robbins Thu, 28 Jun 2012 06:30:32 -0700
On Thu, Jun 28, 2012 at 1:30 PM, Ralph Corderoy <ra...@inputplus.co.uk>wrote:
> Hi, > > Antony Stone wrote: > > Edward Robbins wrote: > > > I guess that means it's basically a brick then? Any plausible way > > > around? > > > > I personally know of no way to reflash it once it's got 5.1, but I'm > > not exactly an expert around here. Others may well be better-informed > > than I am. > > I suppose JTAG using the exposed pads on the circuit board, how the > ROM's contents were obtained originally IIRC, might be a complex > option... > > After scouring the mailing list it doesn't appear that anyone actually ever managed to find all the JTAG pins for the e3. Question is, if I get another emailer from ebay (which in all likelihood will turn out to be PBL 5.1) and remove the SoC to find the test pads, will somebody else with a 4.9 PBL be willing to hook up a JTAG and get a dump for me?
I have the tools to remove the SoC and find the pads, and also have access to a JTAG debugger, but wouldn't know how to go about getting a flash ROM dump even so...
> Is it correct that no revenue is now made from the Emailer family; that > the premium rate numbers have been closed, etc., and whoever bought the > relevant part of Amstrad has no interest in operating it any more? If > so, could an approach to them to make available, e.g. signing key, for > the benefit of those that want to tinker? No skin off their nose now > and if the right person is reached it may work, what with the increased > prominence of the Maker movement, etc. >
This might work, though in my experience they may be prevented from helping simply by company policy or because the people with the relevant knowledge have moved on or are too busy to spend time on something that will generate no revenue. On the other hand it can't hurt to try... any idea what the best line of contact might be? Or how I should frame the question?
> > Cheers, Ralph.
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Post by Spanner on Apr 18, 2019 10:39:46 GMT
Ralph Corderoy Fri, 27 Jul 2012 08:44:16 -0700
Hi Edward,
> > Is it correct that no revenue is now made from the Emailer family; > > that the premium rate numbers have been closed, etc., and whoever > > bought the relevant part of Amstrad has no interest in operating it > > any more? If so, could an approach to them to make available, e.g. > > signing key, for the benefit of those that want to tinker? No skin > > off their nose now and if the right person is reached it may work, > > what with the increased prominence of the Maker movement, etc. > > This might work, though in my experience they may be prevented from > helping simply by company policy or because the people with the > relevant knowledge have moved on or are too busy to spend time on > something that will generate no revenue. On the other hand it can't > hurt to try... any idea what the best line of contact might be? Or how > I should frame the question?
Cliff Lawson, the creator of the Emailer family, might know who owns the rights and how to go about contacting them. I'll send you his email address off-list. If they are effectively bricks without the Amstrad infrastructure support then he may like to see them getting some use by being opened up more.
Cheers, Ralph.
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Post by Spanner on Apr 18, 2019 10:41:30 GMT
Edward Robbins Wed, 17 Oct 2012 06:25:16 -0700
> Cliff Lawson, the creator of the Emailer family, might know who owns the > rights and how to go about contacting them. I'll send you his email > address off-list. If they are effectively bricks without the Amstrad > infrastructure support then he may like to see them getting some use by > being opened up more. >
Some progress - I recently finished some work so had some free time to look at the emailer again. I emailed Cliff Lawson (thanks for the contact Ralph) and he does indeed seem willing to help. He gave me some information about how the images are signed in PBL 5.1! He says:
"all I can tell you is that the signature I added uses SHA256 and the key is the first two or three sentences of the King James Bible ("In the beginning was the word..."). ... note that SHA256 like all hashses (MD5 etc) is sensitive to every last space and bit of punctuation so even if you get the words right if you miss a comma or a semi-colon it will not sign. Again I forget the exact details but I did it very like CHAP authentication so first the "key" and then the bytes of the image are passed through the hash and then I cannot remember if the SHA256 hash output was then put in the header or a footer to the image and the PBL also has the key built in (actually I think it may be held like a module in Nand) it passes that then the delivered data through an SHA256 and only if it gets the same hash does it unlock the flash programming routines."
So not quite there, but this might be enough to reverse engineer the format enough to get PBL5.1 machines to accept an image. If I understand correctly with PBL5.1 the machine wont accept an image over serial though, so this would have to be done by dialling in to another modem?
Cliff did say he will have a look and see if he can find any source code that might have more information. In which case we might not have to go through the reverse engineering stage, but I'm not certain he will actually find anything.
I actually went ahead and bought another new emailer as well - and it was brand new, unopened. So it has PBL4.9 and my need to get the other one working has kind of gone.
Ed
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Post by Spanner on Apr 18, 2019 10:42:34 GMT
Ralph Corderoy Wed, 17 Oct 2012 08:30:24 -0700
Hi Edward,
Thanks for coming back to us with the info from Cliff.
> If I understand correctly with PBL5.1 the machine wont accept an image > over serial though, so this would have to be done by dialling in to > another modem?
Is that true? IIRC, years ago Cliff suggested one way Amstrad could meet my interpretation of their GPL2 requirements having implemented signing was for me to send him my image for him to sign as part of the build process. His implication being that I could then upload it over serial as before?
It could be 5.1's modem-only has been established as fact and I've forgotten.
Cheers, Ralph.
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Post by Spanner on Apr 18, 2019 10:42:54 GMT
Edward Robbins Wed, 17 Oct 2012 08:50:43 -0700
On Wed, Oct 17, 2012 at 4:03 PM, Ralph Corderoy <ra...@inputplus.co.uk> wrote: > Hi Edward, > > Thanks for coming back to us with the info from Cliff. > >> If I understand correctly with PBL5.1 the machine wont accept an image >> over serial though, so this would have to be done by dialling in to >> another modem? > > Is that true? IIRC, years ago Cliff suggested one way Amstrad could > meet my interpretation of their GPL2 requirements having implemented > signing was for me to send him my image for him to sign as part of the > build process. His implication being that I could then upload it over > serial as before? > > It could be 5.1's modem-only has been established as fact and I've > forgotten. >
I'm not sure, it was a guess really. It's just that I don't think you can get into the debug console mode in PBL5.1, so how can you initiate a transfer?
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Post by Spanner on Apr 18, 2019 10:43:52 GMT
Jake Wed, 17 Oct 2012 09:34:41 -0700
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
Yup, I did.. We even know the plaintext length: 392 bytes ..
> On Wed, Oct 17, 2012 at 4:03 PM, Ralph Corderoy <ra...@inputplus.co.uk> wrote: >> Hi Edward, >> >> Thanks for coming back to us with the info from Cliff. >> >>> If I understand correctly with PBL5.1 the machine wont accept an image >>> over serial though, so this would have to be done by dialling in to >>> another modem? >> >> Is that true? IIRC, years ago Cliff suggested one way Amstrad could >> meet my interpretation of their GPL2 requirements having implemented >> signing was for me to send him my image for him to sign as part of the >> build process. His implication being that I could then upload it over >> serial as before? >> >> It could be 5.1's modem-only has been established as fact and I've >> forgotten. >> > > I'm not sure, it was a guess really. It's just that I don't think you > can get into the debug console mode in PBL5.1, so how can you initiate > a transfer?
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Post by Spanner on Apr 18, 2019 10:44:32 GMT
Jake Wed, 17 Oct 2012 09:45:28 -0700
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
The 5.1 PBL requires a handshake first ( as previously discussed on list ) of the aforementioned key as a blob. Once it gets that, the old flashing commands are all available.. I think I actually posted the sig of the key on list ?
> On Wed, Oct 17, 2012 at 4:03 PM, Ralph Corderoy <ra...@inputplus.co.uk> wrote: >> Hi Edward, >> >> Thanks for coming back to us with the info from Cliff. >> >>> If I understand correctly with PBL5.1 the machine wont accept an image >>> over serial though, so this would have to be done by dialling in to >>> another modem? >> >> Is that true? IIRC, years ago Cliff suggested one way Amstrad could >> meet my interpretation of their GPL2 requirements having implemented >> signing was for me to send him my image for him to sign as part of the >> build process. His implication being that I could then upload it over >> serial as before? >> >> It could be 5.1's modem-only has been established as fact and I've >> forgotten. >> > > I'm not sure, it was a guess really. It's just that I don't think you > can get into the debug console mode in PBL5.1, so how can you initiate > a transfer? >
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Post by Spanner on Apr 18, 2019 10:45:27 GMT
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Post by Spanner on Apr 18, 2019 10:45:49 GMT
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