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Author Topic: Towards Microcore on Allwinner A10  (Read 40247 times)

Offline caminati

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Towards Microcore on Allwinner A10
« on: August 12, 2012, 07:00:20 AM »
Hello, I managed to set up a quite experimental minimal console linux on my tablet, as announced here:
http://lists.phcomp.co.uk/pipermail/arm-netbook/2012-August/005528.html

I deem this a substantial step towards microcore.
Indeed now I can work directly on my tablet to add the missing pieces to get Microcore: basically, udev, very few busybox applets missing, some other /bin and /sbin proggie, and /lib/modules.
Being targeted at only one specific machine, I guess the last one should be easier, with much fewer peripherals possibly running.

The most important step for further developments, however, is to get some kind of toolchain set (for the time being I am stealing binaries from Debian armhf :) ): gcc (or tcc?), eglibc (or uclibc?), linux headers, and this is harder.
How do I pack up eglibc, for example? Also, I have no idea of how to skim linux kernel headers from the sources, though this should be easier.

After that, repacking at least the most basic tczs for the new arch should be relatively straightforward.
It would be even more so if we had a strict policy of requiring buildscript(s) for each extension submitted, which now is quite loose (ibiblio src/ directory is, well, meager).
Maybe bitbake could help here? Or even leaving the choice of the script language to the submitter: any kind of automation would be of great help.

Another problem is that I don't have much spare time left to devote to that right now.
Anybody owning Allwinner hardware is welcome to join the effort.

« Last Edit: August 12, 2012, 10:18:45 AM by caminati »

Offline roberts

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Re: Towards Microcore on Allwinner A10
« Reply #1 on: August 12, 2012, 08:52:57 AM »
Awesome. I will definitely have a look.
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Offline tinypoodle

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Re: Towards Microcore on Allwinner A10
« Reply #2 on: August 13, 2012, 04:51:10 AM »
very few busybox applets missing

Not sure, but have you had a look at http://busybox.net/downloads/binaries/latest/ already?
"Software gets slower faster than hardware gets faster." Niklaus Wirth - A Plea for Lean Software (1995)

Offline caminati

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Re: Towards Microcore on Allwinner A10
« Reply #3 on: August 13, 2012, 05:24:35 AM »
Not sure, but have you had a look at http://busybox.net/downloads/binaries/latest/ already?

Well... no, because I just took the first working binary I found.
I just followed your suggestion, and tested armv6l which seems to work on the tablet!
Probably slower than debian armhf's one, but at this stage that's ok.
Hence: first problem solved, thanks. :)

Offline caminati

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Re: Towards Microcore on Allwinner A10
« Reply #4 on: August 13, 2012, 09:08:01 AM »
Another important point is that busybox suggested by tinypoodle has standalone shell disabled, which is needed for e.g. coreutils!

Now I have only three busybox applets missing:
ar, taskset, uncompress

Before I start digging core.gz to know whether I actually need them, do you think I need them? :)

Offline roberts

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Re: Towards Microcore on Allwinner A10
« Reply #5 on: August 14, 2012, 12:14:54 PM »
@caminati, Sorry but I did not have any success with your kernel & rootfs. But it is likely because  I don't have an Allwinner tablet.
Probably a script.bin (evb.bin) or some such. Seems Allwinner just about needs hardware packs of specific boot bin files.

Anyway, I am extending my kit methodology to my Allwinner A10 Mele. I believe I had Core booting. But alas I need to add X to be sure. So I continue with great hope for a mele-kit. 
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Offline caminati

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Re: Towards Microcore on Allwinner A10
« Reply #6 on: August 14, 2012, 02:25:32 PM »
@caminati, Sorry but I did not have any success with your kernel & rootfs. But it is likely because  I don't have an Allwinner tablet.
Probably a script.bin (evb.bin) or some such. Seems Allwinner just about needs hardware packs of specific boot bin files.

Anyway, I am extending my kit methodology to my Allwinner A10 Mele. I believe I had Core booting. But alas I need to add X to be sure. So I continue with great hope for a mele-kit.

Thanks for testing it, I hope it didn't waste too much of your time.
I have not clear if you got any other distro successfully booting on your Mele: in this case you should stick with the corresponding script.bin, evb.bin, sun4i-spl.bin and u-boot.bin to couple with other kernels and rootfs'.

I am working in a much less general way than you're doing with your kits.
I think I have a good initrd for Core, but I am going mad after u-boot: I'm having no success in passing it an initramfs (been working with a standard rootfs til now).
Heck, I am not even managing to pass it any boot parameter, while I have some showing up in /proc/cmdline from nowhere.
Going to ask for help on arm-netbook, and hope I can understand what's going on.

Regarding how to make sure you successfully booted: without fbcon and hardware console, you can rely on usb pens flashing, and on /var/log: in my rootfs I placed klogd at the beginning of init right for this reason.
To complicate matters, my microsd's all show some remarkable inconstancy: they boot roughly just half the times.

Offline caminati

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Re: Towards Microcore on Allwinner A10
« Reply #7 on: August 17, 2012, 12:08:50 PM »
I packed a much more complete port of Micro Core, not even an alpha, though.
I am uploading it right now:
caminati.net.tf
or, equivalently:
https://sites.google.com/site/marcocaminati/
It is a tar.bz2 with the separate components to be installed manually, if anybody wants a whole media image for simplicity, I can provide it.

Anyhow: now Core scripts are all there, even though actually tc-config is not completing yet.
Refer to the included README.
There I also explain the approach I adopted to port, somehow more streamlined than before, after seeing Robert's Rpi kit.

Offline caminati

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Re: Towards Microcore on Allwinner A10
« Reply #8 on: August 17, 2012, 01:37:19 PM »
I took a screenshot from /dev/fb0 via rawtoppm (well, no camera or whatsoever here). See attachment (I don't know why the background turned out to be grayish, it is actually white). Boot time is about 10 seconds :)
Ok, tc-config does little of what it is supposed to do, still...
« Last Edit: August 17, 2012, 01:45:18 PM by caminati »

Offline curaga

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Re: Towards Microcore on Allwinner A10
« Reply #9 on: August 18, 2012, 01:19:34 AM »
Dear god that font :P
The only barriers that can stop you are the ones you create yourself.

Offline caminati

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Re: Towards Microcore on Allwinner A10
« Reply #10 on: August 18, 2012, 01:58:21 AM »
Dear god that font :P

It's the one from ttf-ocra-font.tcz on ibiblio.
I find it is quite readable, and on the tablet's lcd little else matters.
It occupies a tiny amount of bytes, too; what else one could want? :)
I have to confess it misses ~ and ^ glyphs.
However, I could convert any ttf or bdf font.
Any suggestion?

Offline curaga

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Re: Towards Microcore on Allwinner A10
« Reply #11 on: August 18, 2012, 02:12:32 AM »
Curious, because the TTF Ocra screenshots don't look even nearly as bad. Perhaps it's due to the conversion.

(I like bitstream vera sans mono, but since the ocra was mangled too, I doubt changing the source font would help.)
The only barriers that can stop you are the ones you create yourself.

Offline tinypoodle

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Re: Towards Microcore on Allwinner A10
« Reply #12 on: August 18, 2012, 02:27:18 AM »
I took a screenshot from /dev/fb0 via rawtoppm (well, no camera or whatsoever here). See attachment (I don't know why the background turned out to be grayish, it is actually white). Boot time is about 10 seconds :)
Ok, tc-config does little of what it is supposed to do, still...

"Created with GIMP" ??
"Software gets slower faster than hardware gets faster." Niklaus Wirth - A Plea for Lean Software (1995)

Offline caminati

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Re: Towards Microcore on Allwinner A10
« Reply #13 on: August 18, 2012, 02:35:00 AM »
Quote from: tinypoodle link=topic=13827.msg77595#msg77595

"Created with GIMP" ??

I had to cut the lower half of rawtoppm output, which was full of mess.
Mmm, maybe this has to do with how horrible the shot looks; for sure it is not OcrA's fault.
If I have time I will try to understand better the raw framebuffer pixel format and get a decent screenshot.

Online Rich

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Re: Towards Microcore on Allwinner A10
« Reply #14 on: August 18, 2012, 04:20:52 AM »
Hi tinypoodle
Quote
"Created with GIMP" ??
Sounds like he may have used  netpbm.