[wrxtasy]

Yes via Petitboot. Research the HardKernel forums about that and the HardKernel WiKi.

You can select either SD card or eMMC Android with the A2 remote to boot to either OS.

OK, i read on Hardkernel, but i would like to get know if understood correct.

1. I can buy N2 with preinstalled CE i.e. from here:
https://www.hardkernel.com/shop/odroid-n...c-edition/
Here i get N2 in case with power supply with CE on SD card. CE is not really preinstalled on N2?

CE is pre installed with the N2 - CE edition - and runs from the supplied microSDHC - out of the box.

2. What i need to buy more is Android on i.e. eMMC card like this, i.e. from here:
https://www.hardkernel.com/shop/16gb-emm...2-android/
Adapter is not needed?

You need a dirt cheap eMMC > microSDHC adapter if you want to re-flash any other OS image to the eMMC module:
https://www.hardkernel.com/shop/emmc-mod...s-upgrade/

That whole contraption then slides into a microSDHC > SD card adapter for flashing.

3. Next i read on hardkernel wiki i can upgrade Petitboot (using SD card with SPI switched to eMMC):
https://wiki.odroid.com/odroid-n2/os_images/petitboot
But its said on site: "This instruction is suggested only when you have Petitboot which can boot from SPI flash memory"
It means i should have Petitboot installed previously. Is Petitboot really preinstalled on N2?

Yes Petitboot is already installed. It can also be upgraded.
You can do it from the microSDHC card. (temporarily move all CE files into a seperate Temp directory)

4. After somehow i install/upgrade Petitboot, i can plug eMMC with Android, SD card with CE.
I can change boot OS from SPI selector.
If selector i set to SPI it means that Petitboot runs and i can choose SD (CE) or eMMC (Android) using remote?

Yes there is a basic text user interface, that is also user configurable to boot to either OS. You can also manually select either from a Wireless remote that uses a USB Mini receiver dongle like a MINIX A2 lite.

Is anything else i should have? I already have Airmouse H1 instead of MINIX A2 lite.

The Airmouse H1 needs to use it's own USB Mini dongle RF receiver otherwise Petitboot - user selection of either OS will not work.
Bluetooth only remotes will not work.

WiFi Module 5A needed if you want AC WiFi.
Any old cheap Bluetooth CSR USB dongle will work.