Hi.
where can i download the linux image for my a20 olinuxino Rev E with nand flash
Which board exactly do you have? A20-OLinuXino-WHAT?
Generally, all A20-related images can be found at this FTP but I can point you to a specific image if I know the exact board: ftp://staging.olimex.com/Allwinner_Images/
A20-Olinuxino-Micro with nand flash Rev E
Generally, to install Linux to the NAND you need to prepare a card with the proper Linux image, then boot from that card and run nand install script. After the script completes successfully you can remove the card and boot from the NAND. For the NAND memory of A20-OLinuXino-MICRO you should use this image:
ftp://staging.olimex.com/Allwinner_Images/A20-OLinuXino-MICRO/Debian/sd/A20_OLinuxino_Micro_debian_Jessie_34_103_2G_NAND_release_15.7z
Can also be downloaded via this torrent:
ftp://staging.olimex.com/Allwinner_Images/A20-OLinuXino-MICRO/Debian/sd/A20_OLinuxino_Micro_debian_Jessie_34_103_2G_NAND_release_15.torrent
You need to use older images with kernel 3.4.x, since mainline doesn't support NAND boot (only eMMC boot). With the mainline images the NAND can be used only for storage, not boot. It is something that is not being worked on as far as I am aware, you can also read about it here:
https://forum.armbian.com/topic/6377-nand-install-on-mainline-kernel/