Subject: Re: [E3-hacking] Just got an e3 - where do I start

From: Edward Robbins <[email-masked]>
Date: Wed, 27 Jun 2012 00:08:56 +0100

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.

On Tue, Jun 26, 2012 at 11:45 PM, Edward Robbins <[email-masked]
> wrote:

> 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
>

---

From: Edward Robbins <[email-masked]>
Date: Tue, 26 Jun 2012 23:45:19 +0100

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!

Thanks,
Ed

---

From: Edward Robbins <[email-masked]>
Date: Wed, 27 Jun 2012 00:17:51 +0100

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?

On Wed, Jun 27, 2012 at 12:08 AM, Edward Robbins <[email-masked]

> On Tue, Jun 26, 2012 at 11:45 PM, Edward Robbins <
> [email-masked]> wrote:
>
>> Hello e3 hackers,
>>
>> 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?
>>

---

From: Antony Stone <[email-masked]>
Date: Wed, 27 Jun 2012 00:34:46 +0100

> build a cable, is there a way I can tell which PBL I have from the serial

See the first line of http://www.earth.li/%7Enoodles/files/delta.boot (linked 
from http://www.earth.li/~noodles/hardware-e3.html).

Hope this helps,

Antony.

-- 
All generalisations are inaccurate.

---

From: Janusz Krzysztofik <[email-masked]>
Date: Wed, 27 Jun 2012 21:52:46 +0200

On Tue, 26 Jun 2012 23:45:19 Edward Robbins wrote:
> 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 use the old install tools, ramdisk and procedure published in 2006. 
Works with new kernels built with my defconfig.

Thanks,
Janusz

---

From: Aaro Koskinen <[email-masked]>
Date: Fri, 6 Jul 2012 20:55:20 +0300

Hi,

> 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.