Judging from the conclusion of the command "printenv" on your Board uses a standard u-boot, which can use a universal multiload. You can try to activate multi-boot with Android (as it is on all TV boxes) ? And then show the output of the "printenv" command again.
To reduce the size of memory reservations, you need to change the dtb file and the kernel configuration.
What exact image of Armbian do you use ? What version of the firmware in the eMMC ? What exact model and what dtb file is used ?
I need to see the output of the "printenv" command from u-boot. Need to leave to run u-boot and execute the command "printenv" and "help". The result is shown here.
A new u-boot is needed to run kernel 4.9. I checked on my Tronsmart Vega S96 (S912) - with the dtb from VIM2 and the new u-boot system working with the 4.9 core.
I don't keep old images (of too many). Maybe someone of the users has them. Or you can try to install an older kernel from the options.
https://yadi.sk/d/LBA4bXk_32RGZ6
For the new 4.9 kernel, you can only use dtb files from an image (from the /dtb directory). Any of firmware with Android 7 (it uses a kernel 4.9). Dtb files from kernel 3.14 are not compatible with kernel 4.9.
Thank you for offering me help. But I had already decided this question.
Are you familiar with Linux commands ? The easiest solution is to run on a Linux PC, connect the new card (8Gb), create two partitions on it with labels BOOT (about 90-100 MB) and ROOTFS (everything else). Connect the old card (16 GB) and copy all the files from the old card to the new one from the root user.
You have the s812. The message about chip 805 refers to the bootloader that is part of the image. What steps did you take ? Why do you start u-boot from SD card ? Did you remove the regular u-boot from NAND ?
The latest version of kernel packages (20180216) can be installed as you wrote. In this version of the deb packages have all the wifi modules. In previous versions of deb packages (< 20180216), this was not the case. The complete set of modules could only be obtained from the image. I don't have network repositories for installing packages yet.
Try to use the image 20180216. In the kernel with updated modules WiFi and added module sv6051.
I pay attention all, in connection with change of sources, the module name for qca9377 changed, now it is called "wlan".