Building the Linux Kernel 3.0.8 For Telechips TCC8925 mini PCs (CX-01, Z900, TizzBird N1…)

Yesterday, we got Linux kernel 3.0.8 source code from Telechips, as well as some files related to Android 4.0 (Webkit + OMX). Today, I’ve had a look at the kernel source code and found a few very interesting things.

First let’s get the code from github:


Good news! The code for the latest Telechips TCC892X is present in arch/arm/mach-tcc892x, and there is support for 3 types of boards:

  • board-m805_892x – TCC8923 M805 board
  • board-tcc8920 – TCC8920 evaluation board
  • board-tcc8920st – TCC8920 STB evaluation board

TCC8920 STB evaluation board appears to be relevant to products such as Diyomate A6, but if it’s also used for TCC8925 HDMI Dongle such as CX-01 mini PC, Zero Devices Z900 or ValuePlus TizzBird N1.

Now let’s have a look at the default config directory for arm (arch/arm/configs):


Nice! tcc8925st_dongle_defconfig and tcc8925st_donglehs_defconfig look particularly interesting!

TCC892X Boards Selection

A quick comparison shows that the only difference is that tcc8925st_donglehs_defconfig sets CONFIG_HDMI_DONGLE_CLOCK_HIGH_SPEED=y.

Looking further in the source code:


So tcc8925st_dongle_defconfig configuration file sets TCC8925 to run at 716.5 MHz and tcc8925st_donglehs_defconfig to 812.5 MHz.

The kernel configuration enables the Android stuff, so it’s probably the kernel we’ve got in the device running Android. Let’s try to build the kernel with TCC8925 clocked at 812.5 Mhz (High Speed config) assuming you’ve got the ARM toolchain already installed (run apt-get install gcc-arm-linux-gnueabihf in Ubuntu, if you don’t):


Good! It can build! We now have got the kernel (zImage and uImage) in arch/arm/boot. Let’s build the kernel modules:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j2 uImage INSTALL_MOD_PATH=build_modules modules
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j2 uImage INSTALL_MOD_PATH=build_modules modules_install

The kernel modules are located in build_modules directory. There are only 2 kernel modules: gspca_main.ko (video driver) and scsi_wait_scan.ko.

I cannot give it a try now, as I haven’t received the hardware yet. The other thing I would like to get before hacking CX-01 mini PC is a recovery firmware, and the eventual tools to recover the device when something bad happens. I’ve contacted PandaWill to try to get it. The bootloader code would also be nice, but not an absolute must. However, I believe it’s unlikely we’ll get the bootloader source code since Telechips does not appear to have released it for the older versions of its TCC processors.

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$77.30 SAA-250 Telechips TCC8925 BoardHairybikerHow to Create a Custom Android Firmware for CX-01 mini PC | CNXSoft – Embedded Software DevelopmentKlaus Recent comment authors
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max
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max

Great.
Is this Linux kernel source code (+ android webkit tools etc) has been released for Allwinner A10 series processors or related boards also ?

Or the development done by community on these has been done solely by hacking / cracking the modules?

myxa78
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myxa78

“I’ve contacted PandaWill to try to get it”
Have you got an answer about firmware?

trackback

[…] and the board “tcc8920st_evm” which looks like something I found in the kernel source code, but I was still expecting something with tcc8925 in the code, so the board I have may really use […]

myxa78
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myxa78

cnxsoft :@ myxa78 This is where I asked: http://www.pandawillforum.com/showthread.php?11641-New-Arrival-CX-01-Mini-Android-TV-Box-Android-4-0-Cortex-A5-HDMI-USB-4GB&p=67330&viewfull=1#post67330I think you are there as well. We should try to get a firmware and a method to root it, or a rooted firmware.

i root it without trouble…it’s easy
but i need to backup firmware and tools for reflash it, tommorow i’m chatting with PandaWill, and they said that asked manafacture again
waiting…

tatubias
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tatubias

Can we add here the Bluetooth support and 3gdongles support?

Romfont
Guest
Romfont

What about wlan.ko?

Romfont
Guest
Romfont

Oh, and if you want to test, just boot into fastboot (adb reboot-bootloader), and then you can simply boot the device with your custom kernel.

groovey2k
Guest
groovey2k

Hi did anyone test the kernel yet after the firmware is released? My device seems to be clocked at 1008Mhz according to Overclock tools and Antutu as opposed to other peoples posts, where it says 808Mhz (http://www.androidtablets.net/forum/mcbub-com/41411-new-arrival-cx-01-c77-mini-android-pc-android-tv-box-android-4-0-cortex-a5-hdmi.html).
Anyway, I think this higher clock makes my device very unstable, so HDMI output is often lost 20 min after boot up, also my Antutu score isn’t really better.
My Rom Version is the same as all the others V1.0 20120710
So maybe I could use the kernel you compiled to make the device more stable or is there any other possibility to change the CPU frequency?

Klaus
Guest
Klaus

Hi cnx,

It would be awesome if you could try this Kernel on the CX-01. The Firmware is now awaliable 🙂

Maybe there are some Performance benefits 🙂

Regards
Klaus

Klaus
Guest
Klaus

@cnxsoft

Yeay, thanks a lot 🙂

groovey2k
Guest
groovey2k

@cnxsoft
Yes absolutely sure, is exactly the same device as yours.

groovey2k
Guest
groovey2k

@cnxsoft
Hi I tried to compile the kernel (716,5 Mhz version) unfortunately I don’t get a uimage after the process. There are a lot of warnings (functions and variables not used or wrong variable type) during the compilation. Did you have the same warnings during compilation?

Also my compilation ends with:
LD net/wireless/cfg80211.o
LD net/wireless/built-in.o
CC net/activity_stats.o
LD net/built-in.o

No mention of an ready image like in your post.

Am I missing some packages? I’m running ubuntu 12.04 in virtualbox.

groovey2k
Guest
groovey2k

I finally managed to build the kernel with another ubuntu version (but it might be that the path was to deep using “telechips-linux” as name).
Anyway after building the zImage I tried to boot it using fastboot. “adb reboot bootloader” usually starts the fastboot mode where you could temporarily boot an zImage and try it and afterwards flash it permanent (you must have android sdk installed to do that).
Anyway the “adb reboot bootloader” command did restart the device in a special mode and it asked for driver installation. I installed the adb drivers again. But after that the device doesn’t react to the fastboot commands.
So I wasn’t able to flash the kernel. Maybe we need special fastboot drivers.
Also if you send “adb reboot recovery” it boots in the recovery mode but I don’t know if this helps with anything. All adb commands work in this mode.
I’m already on the newer firmware you mentioned. But for some reason quadrant still tells me that my device is clocked at 1008mhz amd it’s still unstable. I don’t know why, maybe it’s a hardware failure.

groovey2k
Guest
groovey2k

@cnxsoft
also maybe this documentation has some useful info for us:
http://wenku.baidu.com/view/e7bd54f79e314332396893c8.html

myxa78
Guest
myxa78

@Klaus
it’s antutu said?
1008Mhz=808Mhz CPU + 200Mhz GPU
TCC8925 by documention max.freg=833 Mhz so freq of CPU can’t be 1008

trackback

[…] instructions are available in Building the Linux Kernel 3.0.8 For Telechips TCC8925 mini PCs, but use cx-01 config […]

Hairybiker
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Hairybiker

We have been trying to compile a kernel with extra modules, or even just enable loading of extra modules, but even though it compiles it will NOT boot the device.

Do you have any further info on this, we think it may need the lk.rom build as well, which isn’t in the current build instructions.

trackback

[…] probably out of luck if you want to find the original firmware. Telechips TCC8925 did release the Linux kernel and part of Android source code, so in theory Linux could run on the board as well, without GPU and VPU support. One the advantage […]

trackback

[…] well first time doing this, not much to expect, im going to use this guide to compile the kernel, Building the Linux Kernel 3.0.8 For Telechips TCC8925 mini PCs (CX-01, Z900, TizzBird N1?) any suggest? Reply With […]