How to create the img file to use with etcher once you build the android SDK?

[octavian]

How do we construct the single .img file like the one that is distrIibuted on the wiki after we build the Android ROM?

I found these steps for flashing:

rkdeveloptool is here: http://opensource.rock-chips.com/wiki_Rkdeveloptool
Get the board into bootrom mode. Short the two pins next to the LEDs and hit reset.

Code:

cd rockdev/Image-rk3328_box rkdeveloptool db MiniLoaderAll.bin rkdeveloptool ef rkdeveloptool gpt parameter.txt rkdeveloptool ppt rkdeveloptool ul MiniLoaderAll.bin rkdeveloptool wlx uboot uboot.img rkdeveloptool wlx trust trust.img rkdeveloptool wlx misc misc.img rkdeveloptool wlx baseparameter baseparameter.img rkdeveloptool wlx resource resource.img rkdeveloptool wlx kernel kernel.img rkdeveloptool wlx dtbo dtbo.img rkdeveloptool wlx vbmeta vbmeta.img rkdeveloptool wlx boot boot.img rkdeveloptool wlx recovery recovery.img rkdeveloptool wlx system system.img rkdeveloptool wlx vendor vendor.img rkdeveloptool wlx oem oem.img rkdeveloptool rd

I believe the tool you're looking for is located in `$SDK_ROOT/RKTools/Linux/Linux_Pack_Firmware`.
Reading the `mkupdate.sh` script, it seems to be doing exactly that. Not sure how the OTA packages for install in recovery are created, but those should have a .zip extension.