Nightly test image not booting on a VIM3/PRO

1st Official Post

    Hello,

    sorry to bother here with this my newbie question but using VIM3/PRO I can't boot with LibreELEC-AMLG12.arm-9.80-nightly-20200514-cf26681-khadas-vim3.img.gz.

    The upgrade mode just ignores the SD card containing the image.

    Looking inside its structure I don't see any dtb.img or uENV.ini files. While believing that perfecly normal, I noted also that in / is a dtb file apparenty appropriate for my hw (meson-g12b-a311d-khadas-vim3.dtb) while in /extlinux is a extlinux.conf with reasonable config hints pointing to the related files. What I am missing to understand?

    Thank you for the help

    Marco

    • Official Post

    The image you downloaded is for eMMC install. It will not boot from an SD card unless the eMMC has been wiped. If you want to keep Android or some other Linux on the eMMC you can use the "box" image, edit the dtb name in uEnv.ini first. Once booted from SD, you can use "emmctool" to write the other emmc image to the internal storage.

    I am on a steep learning curve, sorry for that, I am crawling step by step :)

    I took the test image path because I realized that the LibreELEC.USB-SD.Creator.Win32 tool cannot really burn an image for VIM3 (just KVIM).

    So, based on my basic knowledge with VIM3 so far, I would keep Android on eMMC as an essential mean for entering upgrade mode via Power/Reset keys, as I learnt in practice when booting SD images. Is that correct?

    Also, I am a bit puzzled when you say "once booted from SD". I would not want to skip necessary steps but let me ask what bootable SD image you really mean in your suggestion.

    Thanks!

    Marco

    • Official Post

    There are two ways to boot the VIM3 .. from SD card, from eMMC.

    From SD card: write LibreELEC-AMLG12.arm-9.80-devel-20200426060538-38764c8-box.img.gz to an SD card, download Dropbox - u-boot.ext - Simplify your life and place it in the root folder of the SD card, then put the VIM3 board in update mode, it will find the SD card, and LE will install.

    From eMMC: follow the SD card install procedure, then run the following commands:

    Code
    cd /storage
wget https://test.libreelec.tv/LibreELEC-AMLG12.arm-9.80-devel-20200426060538-38764c8-khadas-vim3.img.gz
emmctool w LibreELEC-AMLG12.arm-9.80-devel-20200426060538-38764c8-khadas-vim3.img.gz

    This downloads the eMMC install image to /storage and writes it to the internal eMMC storage, overwriting Android. Now power off the board, remove the SD card, and power on again. It should boot into LE on the eMMC. If you ever want to reinstall Android to eMMC, Khadas have an SD card tool called krsecue that will help you do this.

    USB/SD Creator works fine for writing SD card images for all the test images (not just KVIM) but install to eMMC is a two stage process.

    With your help and tips I sorted out my problems. I just noted, compared to android, that hw accelerations have been lost, presumably due the "generic" box SD image. I'll try the eMMC that looks like more proper for the platform.

    Thanks

    Marco

    Just a brief update, trying the eMMC image does not also show up use of hardware acceleration. I'll stay tuned as further releases come.

    Also, I would take advantage to ask you one more question. You said that installing to eMMC is a two stage process, as that I successfully followed according to your tips. Could the USB Burning tool V2.2.0 also be used to write the image from the PC in just one stage?

    Many thanks!

    Marco

    • Official Post

    HW acceleration is still a bit work in progress. It was working .. then kernel side was reworked around a newly finalised API late last year and that needed a bunch of rework in FFmpeg which has taken an age to happen. It is now being very actively looked into, but we didn't have a eureka moment that results in publc-usable code yet. However, on VIM3 you should be able to disable HW decoding and it will decode all 1080p content happily - only 4K will be too much. NB: USB Burning Tool uses a proprietary Amlogic "img" format, so not possible to use that.