
C-Sky: A $6 Linux dev board with HDMI and USB - zoobab
https://c-sky.github.io/docs/gx6605s.html
======
robert_foss
These are based on the Nationalchip GX6605S SOC, which has no mainline
support, but C-Sky maintains a kernel supporting it[1].

It also seems to have buildroot support if you want to whip up an embedded
platform based on it[2].

[1]
[https://github.com/c-sky/linux-4.9.y/](https://github.com/c-sky/linux-4.9.y/)

[2]
[https://patchwork.ozlabs.org/patch/734596/](https://patchwork.ozlabs.org/patch/734596/)

~~~
TeMPOraL
How is it that all those cheap boards are always based on chips without proper
support?

~~~
oneplane
Because that would make them expensive. The cost of those boards isn't in the
hardware, it's in the people writing software and the QA that comes with it.

~~~
emilfihlman
That's not the case. You must anyways be able to support them to get anything
done so the software things already exist.

It's just that they don't bother with sharing those docs in English since it's
Asia only pretty much.

~~~
oneplane
No, that's not how it works. Doing proper support means getting your code
mainlined and written and tested according to the rules. Doing a dirty port
with crappy code that still runs is easy and cheap. Delivering a crap fork and
not updating it a year after release is common because of this, same goes for
a lot of commercial stuff.

~~~
jagger27
Exactly. That's why I'm excited for La Frite. Gets price, mainline support,
and performance.

[https://www.kickstarter.com/projects/librecomputer/la-
frite-...](https://www.kickstarter.com/projects/librecomputer/la-frite-open-
source-fries)

~~~
dddw
fancy

------
yitchelle
Serious question. Given the recent story [0] about spying, how much trust
would put on something as obscure as this implementation of a single board
computer?

The lack of trust is not yet mitigated with wide adoption by communities
outside of China.

[0] - [https://www.bloomberg.com/news/features/2018-10-04/the-
big-h...](https://www.bloomberg.com/news/features/2018-10-04/the-big-hack-how-
china-used-a-tiny-chip-to-infiltrate-america-s-top-companies)

~~~
wuxb
China is an imaginary country that never existed. The Chinese people you see
in the U.S. territory are all droids. I'd rather do business with the North
Koreans.

~~~
prolikewh0a
What if this guy is right?

~~~
squarefoot
If he's Finnish chances are that he doesn't exist as well ;)

[https://skeptoid.com/episodes/4573](https://skeptoid.com/episodes/4573)

------
angelsl
FWIW, C-SKY architectural support was recently pulled:
[http://lkml.iu.edu/hypermail/linux/kernel/1810.3/03389.html](http://lkml.iu.edu/hypermail/linux/kernel/1810.3/03389.html)

~~~
mirashii
Pulled in this context means pulled into the tree, not removed as the common
parlance might indicate, for those who were a bit confused like myself.

~~~
klez
Wouldn't the correct (or, at least, less confusing) term then be "merged" if
that's the case?

~~~
sokoloff
"pull" is a git command to merge and update

[https://git-scm.com/docs/git-pull](https://git-scm.com/docs/git-pull)

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aidenn0
There are a lot of cheap linux dev boards out there now, to the point where I
had trouble finding a list of boards that met my requirements[1]. There is
almost certainly a sub-$20 board out there with what I need, but I ended up
using an RPi just because it was "cheap enough" and had what I needed.

1: In this case, analog audio out, 1 host-side USB port, and 6 GPIOs.

~~~
mrsteveman1
The Pi Zero W is my default for the same reason, and most of mine were all of
$5 due to sales at Microcenter. It's pretty hard to beat that unless you need
more CPU power.

Add an industrial MicroSD card for ~$15 (to prevent the infamous SD
corruption) and it's still at the $20 point but far more reliable and
versatile than many of the alternatives.

Even some of my microcontroller boards cost more than that, and you can still
program the Pi boards "bare metal" if you really want to, because they're
popular enough that people have already done the work to make that possible.

P.S., even with a Pi Zero (W or not), you can hook up a tiny I2S audio codec
board for a line level[1] or amplified[2] audio output.

[1]
[https://www.adafruit.com/product/3678](https://www.adafruit.com/product/3678)

[2]
[https://www.adafruit.com/product/3006](https://www.adafruit.com/product/3006)

~~~
aidenn0
Thanks, I didn't know the Pi Zero had I2S pins brought out; kind of funny that
the unamplified board is more expensive (though just from the picture it's
easy to see why; the amplified board is relying on the inductance of the load
for filtering _and_ it lacks the phone jack).

------
goph0
Only 64MB of RAM?

In 2013 I bought
[https://en.wikipedia.org/wiki/CHIP_(computer)](https://en.wikipedia.org/wiki/CHIP_\(computer\))
for 10E including shipping.

ARM Cortex-A8, WiFi, bluetooth, GPIO, i2c, 4GB NAND drive, 512 MB of RAM

Serious question: given that the hardware is open, why is nobody replicating
the same thing at a similar price?

~~~
tango24
2013? That wiki link says the release date was 2016, but the company "had
entered insolvency. Many customers still had not received their pre-orders".
Sounds like it wasn't profitable to create such cheap devices?

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rahimnathwani
It costs 39 CNY plus 9 CNY for domestic China shipping (total just under 7
USD):

[http://m.zrumg.top/h.3PwbrnB?sm=9f6f7c](http://m.zrumg.top/h.3PwbrnB?sm=9f6f7c)

~~~
leemailll
why not this:
[https://item.taobao.com/item.htm?spm=a1z10.1-c-s.w4004-18365...](https://item.taobao.com/item.htm?spm=a1z10.1-c-s.w4004-18365545946.2.27e337f32mS9mV&id=556322544984)

~~~
rahimnathwani
It's the same Taobao listing.

The link I pasted was from the 'share' feature in the Taobao app. I think they
use these obfuscated domains so that the pages don't get blocked from opening
when opened from a social media share. WeChat for example won't open Taobao
links in the internal browser.

EDIT if I 'share' and choose 'SMS' as the destination, the Taobao app puts a
regular link in the clipboard:

[https://taobao.com/awp/core/detail.htm?id=556322544984](https://taobao.com/awp/core/detail.htm?id=556322544984)

------
dazhbog
Interesting that they put a full blown XX32F103 there for jtag and still use a
CH340 for serial. They could easily use the F103 for both, to bring the cost
down (save on USB conn, 12mhz crystal, serial IC, etc). That's savings of 0.30
USD right there.

~~~
sitkack
They probably reused jtag and serial from different projects, which makes
sense for a V1. If it is popular, I am sure they would implement the changes
you list.

------
guoren
newest gx6605s dev feeds:

[https://gitlab.com/c-sky/buildroot/-/jobs/113874636/artifact...](https://gitlab.com/c-sky/buildroot/-/jobs/113874636/artifacts/browse/output/images/)

make from buildroot: git clone
[https://gitlab.com/c-sky/buildroot.git](https://gitlab.com/c-sky/buildroot.git)
cd buildroot make csky_gx6605s_br_defconfig make

USB host controller is OHCI+EHCI in kernel drivers.

HDMI is a very simple framebuffer driver in [https://github.com/c-sky/addons-
linux/tree/master/addons/dri...](https://github.com/c-sky/addons-
linux/tree/master/addons/drivers/video/fbdev/nationalchip)

------
snarfy
No networking it looks like.

Whenever I see these dev boards (and I have dozens), I'm always tempted to
just use a cell phone.

Does your project need networking? A battery? A display? Bluetooth? Try
cobbling together an arduino like solution and you'll spend > $50. You can buy
a smartphone with wifi and touchscreen running android for $10.

~~~
avar
Where can you buy a smartphone with wifi and a touchscreen for $10?

If the answer is "used", then I could also buy something like this $6 board
used for $0.06 in a few years, so that doesn't count.

~~~
morganvachon
Walmart and Target in the US sometimes have closeout sales on their $30
prepaid smartphones that brings them down to the $10 range. They are a huge
loss leader even at $30 because they expect you to sign up and pay for at
least a few months' service.

------
megous
What's the power consumption like? I don't see many potential benefits other
than that, compared to similarly priced Allwinner based SBCs which are more
powerful and better supported currently.

Also for a dev board, there's not much GPIO/other interfaces like I2C or SPI.

~~~
tyingq
It does say this: _" The 5V1A is powered by JTAG and UART micro-usb, so no
additional power interface is required"_

A fair amount of monitors and TVs have a USB port, so it would make a decent
digital signage solution. Assuming you want your content just as files on a
thumb drive.

------
guoren
[https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/?h=v4.20-rc2)

This kernel also could work with gx6605s, you can ref:
[https://gitlab.com/c-sky/buildroot/-/jobs/113874636/artifact...](https://gitlab.com/c-sky/buildroot/-/jobs/113874636/artifacts/browse/output/images/)

dts and kernel-config

------
zoobab
There is also an article on CNX:

[https://www.cnx-software.com/2018/11/12/c-sky-linux-
developm...](https://www.cnx-software.com/2018/11/12/c-sky-linux-development-
board-gx6605s-media-soc/)

------
c0deR3D
Why using XX32F103C8T6 instead of its complete model at specification of UART?

~~~
jack12
Probably because they don't care if it's made by STMicroelectronics or by
GigaDevice. Most likely it is made by GigaDevice, but maybe they thought
calling it a GD32F103C8T6 would be meaningless to many people and calling it
an STM32F103 would be dishonest and so this was a compromise. Or maybe they
found a third source that would have an even less recognized name.

How did things work back in the day of (official) second-sourcing? Did you
just refer to a MC68000 even if you meant generically any of
MC68000/HD68000/MK68000/etc? I guess it helped that it had such a unique model
number and any of them could just be referred to as a 68000. I guess calling
this a 32F103 would be the equivalent in this case.

------
xaduha
Is price a really big deal for these? Do you buy them in bulk for something?

~~~
NullPrefix
Is the price for anything a big deal?

~~~
xaduha
It depends, that's why I'm asking. There isn't much difference between 6 or 12
or 24 to me for something you buy one of, especially if $24 gets you something
much better (e.g. I'd rather buy Orange PI that supports Android). But even
+$1 can be a big deal if you want to buy thousands of them.

------
jononor
C-Sky is a RISC-V member, is this a RISC-V board?

~~~
GrayShade
No: [https://www.phoronix.com/scan.php?page=news_item&px=C-SKY-
Ap...](https://www.phoronix.com/scan.php?page=news_item&px=C-SKY-Approved-
Last-Arch)

~~~
geokon
"I think this may well be the last new CPU architecture we ever add to the
kernel. Both nds32 and c-sky are made by companies that also work on risc-v,
and generally speaking risc-v seems to be killing off any of the minor
licensable instruction set projects.." \-- long-time low-level kernel
developer Arnd Bergmann

Wow.. that's quite the statement. Would be interesting to know more about this
ISA and if it's doing anything interesting and new

~~~
AnssiH
> It was pointed out within minutes of my comment that there is another
> platform getting ready for merging (Kalray MPPA), so my prediction was
> clearly wrong.

[https://lwn.net/Articles/770410/](https://lwn.net/Articles/770410/)

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haddr
Forgive my black humour, but I hope there is no extra spying chip there

~~~
Freak_NL
For €5 an extra spying chip thrown in for free is a steal though.

~~~
saagarjha
Depending on whether you have control of the spying chip.

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emilfihlman
Just give me a board with gigabit ethernet, wifi+bt, emmc (NOT sd for fucks
sake), like 2-4 usb As and a proper power connector (NOT the god damn micro
usb) and I'm happy!

~~~
doughj3
An Orange Pi Plus 2E meets all your needs, but like the other comment noted,
it's going to cost more than $6.

[http://www.orangepi.org/orangepiplus2e/](http://www.orangepi.org/orangepiplus2e/)

~~~
NullPrefix
Mainline kernel support would be nice too.

