[Bob]

Brad:

Thanks for that.. I’ll look later on..

[Bob]

Hi, I’ve bought a “dead” i7 Stylus from Ebay.. The tablet appears to have been opened with a crowbar (not really!). Significant rear case and screen edge damage.

The tablet was supplied with a charger and a USB power lead.. Can you see where this is going yet??

Yep, the “computer place” that I bought the tablet from were trying to charge/power the tablet with 5V (750mA rated charger).

The battery was totally flat. I transferred the battery to my tablet and attempted charging it.. Good news! It fully charged up after 4 hours or so with a 12V 3A charger.

I’ve now installed Linux Mint 18.1 with a self compiled kernel (4.9.0). Everything (so far tested) works apart from auto screen rotation.

Looking good! I’ll continue after Christmas..

BTW, the “faulty” tablet actually isn’t.. It boots correctly with the other battery controller board and Ebay Lipo cells.

I’ll test everything out in the new year.

Hope everyone has a good one…

[Bob]

Hi,

I’ve just resurrected my i7 stylus after a battery failure. I’ve wiped Debian off and installed Mint 18.1 .

I’ve upgraded the kernel to 4.9.0 (compiled on Slackware to .deb packages).

Everything that I’ve tested so far works apart from auto screen rotation… I haven’t looked at this yet .. This is on the “to do” list.

Specifically, these work:-

wifi, bluetooth, touchscreen, audio (speakers), battery level & both cameras.

To do/check: hdmi out, headphone o/p, screen rotation, SD slot..

For those who want to compile their own kernel and don’t know how.. (also see your distro docs/forums for details.)

Overview:

Install required development packages (look for info for your specific distro).

Download the latest kernel archive from https://www.kernel.org/

Extract this to a build directory.

Copy your existing .config from your current kernel source tree to the root of the kernel source tree.

Open a terminal, move to the build directory and enter this:

    yes "" | make oldconfig

This accepts all defaults on newer config options when using a .config from another kernel version:

Now run

   make xconfig

Adjust options as required. Save the file and exit.

Now run this:

    sudo make deb-pkg

This will create the required files archived into deb packages. Mint/Debian/Ubuntu etc. distros can use these files directly.

It’s also possible to extract the contents of each deb package and copy the files over to the required locations manually.

Not quite the recommended method for non-Debian derivatives.. but it works! What you’ll take away from doing this is knowledge of exactly how/where the kernel, modules, header files and firmware files etc. are required to be placed.

I use this method as I use Slackware on my main machines with Mint and Debian on my tablets.

You’ll need to find out how to create your own initrd and how to update your boot loader.. This may be distro specific. See your distro docs/forums etc.

I can recommend grub-customizer for Grub.

B.

 

[Bob]

Hi,

I’m from the UK so postal charges would probably be prohibitive…

If your tablet is really borked then why not either sell the complete tablet as “spares or repair” on Ebay or break it for parts?

I know of a few people that are looking for digitizers and case parts.. The battery alone is worth selling.

[Bob]

Hi,

I’ve located a dead battery from another tablet (a 2S 7.4V). I intend to try and use the controller board from this one with the replacement new cells that I already have.

The capacity of the cells with the replacement board is slightly smaller, so I’ll see if the controller chip is reprogrammable.

I’ve also got a lead on getting a damaged i7 stylus for parts…

More later…

[Bob]

I’m looking for the same.. My i7 stylus battery was “iffy” from new so I bought 2 of the nearest physically sized lipo cells from Ebay.

I didn’t return the tablet as faulty as I bought it direct from China and I didn’t want the aggro. The plan was to remove the battery controller board from the old battery and attach it to the new cells. I’ve done this sort of thing many times on other kit, with no problems.

It worked fine, but the controller board itself failed after about a week. I’m now looking for either a new replacement battery, or a duff one with a working controller board.

I’ll post here if I manage to find anything…

[Bob]

Hi,

Nope, but I understand why you ask…

The following is taken from one of my posts on another forum..

Earlier posts covered both direct ISO boot as well as booting/installing 64bit Linux on a 32bit UEFI tablet (normally Bay Trail powered). I then describe the installation procedure (for non-Linux people).

At this stage, a normal installation is performed to the SD card.

Extract:

For reasons that will be explained shortly, the default installation to SD card cannot boot. It also very probably cannot initially be used on another tablet.

The biggest reason that the default installation will fail to boot is this.
When the tablet is powered on, it is initially not aware of and cannot “see” the SD card slot. i.e. the SD slot hardware is not fully (or at all) initialised by the firmware.

The card slot only becomes “available” when the OS is running.

Booting Linux from the flashdrive results in running system that can easily interact with the SD card slot. The installer detects that a card is inserted into the card slot and can perform a full installation to it. All well and good so far..

But..

If the SD card cannot be seen until the OS is running.. and the OS is installed onto the (so far, “invisible”) SD card, how does the system boot??
The other problem is that the installer has placed all of the boot files to the tablet’s EFI partition and **not** to the EFI partition on the SD card. This would disallow the use of the SD card on another tablet…

The answer to both of these is fairly obvious once you understand the basics of the Linux boot mechanism.

The bootloader (Grub) starts the Linux kernel. This uses a temporary filesystem that is set up in memory (the initrd). This filesystem contains a very small set of drivers that the kernel uses to begin to start the real system. When the startup process has reached a certain point, control is passed to software on the real filesystem and the memory used by initial ram disk is freed. The graphical user interface (desktop) is then started. The user is then free to login.

In the example of a SD card installation, we know that the SD card slot will become available to the system shortly after the initial boot.
We also know how it will be identified by the system **when it is available**. The solution to the initial boot problem is to copy the kernel and initrd to the primary EFI partition. The Grub configuration file is simply altered to point to the these files in this location.
The system is now fully bootable when everything is configured in this way.

Extract end.

Grub files (config & .mod files) are also placed in the tablet’s EFI partition

I just use a simple grub.cfg . Example follows:

menuentry ‘Initial boot, update me’ {
insmod normal
insmod gzio
insmod part_gpt
insmod ext2
set root=’hd1,gpt1′
linux /vmlinuz root=/dev/mmcblk1p2 ##Bay Trail kernel parameters removed as they are not required here.##
initrd /initrd.img
}

This was written for a Linx 7, 8 or 10. These tablets have eMMC storage.

The trick (assuming that the required SD card hardware support is in the initrd) is to start the boot from the primary EFI partition and then pass control to the kernel on the SD card.

The full writeup gives all of the details… if anyone is interested..

I discovered this purely by accident. I had been playing with direct ISO boot and installation on a Linx 8. At the drive selection section I noticed that the installer had identified a 64GB SD card that I had forgotten to remove. (At that time, kernel Bay Trail support was quite poor, I wasn’t even expecting the SD slot to be recognised).

This, coupled with a lot of Windows folk complaining that the SD slot couldn’t be used for booting, led me to experiment.. (aka play)..

I’ll test this on my Cube and report back.

B.

[Bob]

Forgot to say..

You can also directly boot the Linux Mint ISO from anything that can connect to the tablet. Even from a NTFS partition…

B.

[Bob]

Hello All..

First post here..

I’ve managed to get Linx tablets booting Linux Mint from SD card (the card slot is not recognized by the firmware as “bootable”). I see no reason why the same procedure cannot be used here.

My cube is waiting a battery replacement (arrived today). I’m a bit swamped with DIY at the mo, so it will take a couple of days before I can test it.

Essentially, the first stage boot is from the tablet’s EFI partition, the kernel and initrd are copied here. The grub config points to the SD card which “becomes available” i.e. recognised at this stage of booting. Control is passed to the kernel on the SD card in the latter stages of booting. Login and GUI procedures are then started as normal.

If it works on the cube and anyone is interested, then I’ll provide a writeup.

B.

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