Need to reflash BIOS in DnX Mode

[Tschuuuls]

Update: I found the DnX flash program (here).

Problem is: Doesn’t work with the Hi8. It won’t start flashing the BIOS in DnX mode. Will just reboot into the bubbles menu where I could enter the UEFI, if I had a working Keyboard.

On to the Manufacturing Tool…

[Jonathan]

I don’t have the Hi8 so please keep in mind that my suggestions will be a bit hit and miss on this, also I’m pressed for time at present…

Firstly, have you tried holding down the volume down button while booting? You might be able to use the boot menu if there is one on the Hi8.

If that’s no good do you know of a recovery (ideally TWRP) that works on your tablet? (Do not flash anything to try)
Please also confirm that you have the Hi8 (Bay Trail Z3736F, Insyde H2O BIOS) and not the Pro version (Cherry Trail).

[Tschuuuls]

Hi do have the normal HI8, not the Pro Version.

There is a Windows/Android Menu when holding Vol-, but both only boot into EFI shell.

Holding Vol+ in Windows Mode gets me to the screen with the bubbles: “Continue, Boot Manager, Device Management, Boot from File, etc”
I can’t choose anything there without a keyboard.

In Android mode Vol+ gets me into the DnX Mode. It’s detected in Windows just fine.

I found TWRP here: https://www.tablette-chinoise.net/forum/twrp-recovery-v2-8-7-0-t8147 I dont speak french, but with some Google Translate I was able to download the file. It has a Recovery.img inside, so I guess it’s legit.
I tried fastboot booting that yesterday, allready. But using fastboot boot *anything* results in a boot to the bubble menu for me. I guess I have to use the Manufacturer tool (used fastboot on a lot of other devices, so I was confident using it).

I disabled the full screen logo before screwing with USB, that’s why I know my Bios Version is 207. @jonathan

Thanks again!

[Jonathan]

What’s the serial number of your tablet please?

[Tschuuuls]

Hi8 *MYSERIALNUMBER*

[Jonathan]

This is a wild shot in the dark but please try:

1. Connect your tablet to your computer and put it in DnX mode
2. Put this file in the same directory as the TWRP recovery.img you found along with the fastboot files (exe/dll).
3. Start a command prompt in the above directory (from Windows Explorer ALT+D cmd enter).
4. Type “fastboot devices” <enter>
5. Copy the device name
6. Replacing <device> (i.e. no angle brackets)with the device name: type “fastboot -s <device name>  flash osloader efilinux-userdebug.efi” <enter>
7. Replacing <device> (i.e. no angle brackets)with the device name: type “fastboot -s <device name> boot recovery.img” <enter>

This may very well not work 🙂 I’m downloading the official Android files to look for alternatives, but this will take a looongggggg time on my connection…

[Jonathan]

Just to add: step 8 wait 30-45seconds for the tablet to boot once it has the data.

[Tschuuuls]

Stop downloading 🙂

TWRP took a couple seconds to boot, but it worked!

I have adb shell access now!

Attachments:

You must be logged in to view attached files.

[Jonathan]

Progress 🙂

Do you have a working touchscreen?
The Vi10 TWRP doesn’t have ADB, you can get an interactive shell going on yours!?

I’m uploading a modified TWRP for you…

[Tschuuuls]

Yep, shell works as it would in any other TWRP 😀

C:\Users\User\Downloads\TWRP_Chuwi_Hi8>adb shell
~ # [6nls
ls
boot
cache
config
data
default.prop
dev
etc
external_sd
factory
file_contexts
fstab.goldfish
init
init.rc
init.recovery.usb.rc
lib
license
logs
proc
property_contexts
recovery
res
root
sbin
sdcard
seapp_contexts
sepolicy
sideload
supersu
sys
system
tmp
twres
ueventd.anzhen4_mrd7.rc
ueventd.goldfish.rc
ueventd.modules.blacklist
ueventd.rc
usbotg
~ # [6n

 

EDIT: Touchscreen works. Screen update is pretty slow however, probably because it’s drawn without GPU acceleration.

[Jonathan]

Well, as I see it you have two options from here:

1. Grab the correct BIOS for your tablet and set up the ESP volume to flash BIOS when you start up in UEFI Shell (take care not the overwrite the EFI directory).
2. Use the modified TWRP to generate some files for me and let me produce a fix utility (I would be interested in seeing what the UEFI Boot tool did).

EDIT: Removed link to modified TWRP (it needs more testing before it can be made permanently available).

[Tschuuuls]

In Option 1 I would modify the internal partition that tells the Tablet what to boot? Since I can’t boot of the USB flash drive chuwi is suggesting.

I’d choose Option 2. I downloaded the img just now. Which files do I have to pull?

[Jonathan]

Option 1, you DL the BIOS flashing archive and extract the root files (not the subdirectories!) into your ESP volume then restart the (fully charged and on mains power) tablet. No modification of partition tables involved. When your tablet starts it should flash the BIOS.

Option 2, please put a FAT32 formatted SD card into your tablet then boot the img I uploaded just as you did the recovery image. There’s a util included “/sbin/gv” that will create two files in the directory from which it’s run. I suggest: “cd /external_sd” “mkdir gv_gen” “cd gv_gen” “/sbin/gv > log.txt” to contain everything.
I only need the files in the “Vi10_SetupFixLogs” directory of your SD card and the uefi_var.bin generated by gv (please note the other file acpi_var.bin will normally contain your Windows key so don’t post it!).

[Jonathan]

I’m just looking at your other post, you said:
“screwed with OTG Settings, disabled power set OTG to PCI”

Is that all you changed? On the Vi10 those settings don’t disable USB…

[Tschuuuls]

Jonathan wrote:

I’m just looking at your other post, you said: “screwed with OTG Settings, disabled power set OTG to PCI” Is that all you changed? On the Vi10 those settings don’t disable USB…

Yeah, I just disabled the splash screen to show the UEFI version and set boot to legacy fist (was set to UEFI first). But it still booted at this point.
USB got disabled when I changed USB to PCI AND disabled VCC to USB. I tried supplying power to my keyboard with an powered hub. No dice 🙁

Will get you the files in a couple of minutes. Stand by.

[Author]

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