I am using bitbake core-image-base to build a new image file. I know I can flash the .sdcard image file directly. However, the roof file system on this image is basic. And it does not have apt-get as ubuntu does. I wonder how and if I can manually replace the roofts with ubuntu rootfs and the rest remain the same since ubuntu has its own apt-get repository. If this is possible, what kind files do I need to manually put into the two partitions of my SD card.
for example: something such as :
Linux OS kernel image (zImage/Image)
Device tree file (*.dtb) • Bootloader image
Root file system (i.e., EXT4) (with ubuntu root file system)
I am really confused about what files and format (eg. uboot.img?) exactly I need to put in partition one and partition two(rootfs.gz?).