[J-core] Port Idea: Little Kernel

[John Paul Adrian Glaubitz]

On 11/13/2017 04:46 PM, Rob Landley wrote:
> On 11/12/2017 04:05 AM, John Paul Adrian Glaubitz wrote:
>> Let me know if you need a new LANDISK device. I still have plenty of
>> them lying around. I also can tell you how to build your own kernel
>> for the thing and get it to boot. However, I still have the problem
>> that I don't know how to make the IDE driver work. I can get the
>> LANDISK to boot my own, freshly compiled kernel. But it will never
>> detect any IDE devices. But this might be a problem specific to the
>> LANDISK USL-5P devices I have. I never tested it with my HDL-U160
>> device (the same device I had sent to you from Japan).
> 
> The work Cedric is doing on his qemu fork is quite interesting, if we
> can convert landisk to device tree and get that tree to cedric for
> reference, he might be able to get qemu to emulate it.

I thought Yoshinori already converted LANDISK and R2Dplus to device
tree:

> https://lkml.org/lkml/2016/6/29/388

It seems though the patch was never applied.

> A board with more than 64 megs of ram and a single hard drive would be
> nice. (And a battery backed up clock.)
> 
> And, of course, teaching QEMU to emulate the serial buffer the kernel's
> expected it to have for a year now. :)

Yes, qemu-sh4-system with 4 GiB RAM or even just 1 GiB RAM would be
fantastic. I am doing lots of QEMU torture testing on SH4, but that's
all limited to qemu-user and not qemu-system. I helped fixing lots of
bugs in QEMU in any case :).

>> Since the device uses u-boot, it's actually pretty easy to get your
>> own Linux kernel to boot on this device. And since it's reasonably fast,
>> it's also more fun to use as compared to the LANDISK device.
>>
>> However, there is one huge drawback which is that support for ST40
>> was completely removed from the kernel, so it would need to be
>> re-added first:
>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f96691872439ab2071171d4531c4a95b5d493ae5
> 
> Paul Mundt was not acting in the best interests of the Linux kernel.

Well, I think these things just happen when code becomes unmaintained.

I would have preferred for ST40 support to stay in though.

>> There is an out-of-tree kernel patch for the NextVoD but that is
>> still based on 2.6.32:
>>
>>> https://github.com/dlintw/nextvod-tdt
>>
>> If you (or anyone else) is interested on working on this and gettiing
>> the NextVoD working with a current kernel again, I would them send
>> such a NextVoD for free immediately. I would be very interested in
>> getting the NextVoDs supported by a current kernel again as those
>> NextVoDs devices can be acquired in Taiwan for less than US$10!
> 
> If Rich doesn't find time by about February, poke me. (I'm in Tokyo this
> month, then relatives for the holidays, then catching up from all that...)
> 
> Can these be ordered on amazon, or only bought personally in taiwan?

They are called "網樂通" in Chinese. If you go to Yahoo Auction Taiwan,
you can find them:
https://tw.bid.yahoo.com/search/auction/product?kw=%E7%B6%B2%E6%A8%82%E9%80%9A&p=%E7%B6%B2%E6%A8%82%E9%80%9A

And you can probably use a service like this one to buy them from abroad:

> http://www.letsgobuy-tw.com/

I have used Rinkya! for Yahoo Auction Japan before and it works quite
well. I haven't used the service in Taiwan yet though.

Either way, the NextVoD devices are probably the best SuperH hardware
you can buy cheap these days and which easily allows to install
a custom version of Linux.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913