Best way to build kernel and choose filesystem/rootfs etc.

[dluberger]

So I've got all my hardware tested and everything works on my custom board, but I really need to pare things down to bare minima because I want my device to boot as fast as possible, draw the least amount of power necessary, and give me the ability to do what I want. I'm building u-boot, kernel, and device tree from the source code using the Make command in a linux host environment.  I'm not sure at all what filesystem or rootfs (not sure what to call it), for example linaro debian (which takes several minutes to get to the desktop environment on my 5" LCD). Most of my research keeps pointing me to Yocto, but I really want to avoid that because it's just too complicated and takes way too long to do anything at all with.  Building from source seems the fastest and most efficient way to go.

That said, what I want to end up with is a system that can display a UI on a 5" paralllel LCD, talk to a couple of i2c devices like the tsc2007 touchscreen controller and a battery fuelgauge, and run a UI on startup that I build in C# in xamarin and run with mono.  How do I reach my goals??  All of the documentation I've been looking at keeps pointing me to Yocto, but surely there's a better/faster/easier way.

[gusarambula]

Hello David Luberger,

The i.MX BSP uses Yocto as a mean to distribute and allow for customization of Linux images for the supported boards. (Yocto is not a Linux Distribution, it allows you to build a customized one).

I understand your predicament as a Yocto build does require time and resources, but I’m afraid that unlike the bootloader and kernel there is not a straightforward method to build the rootfs outside of the Yocto environment. At least when talking of NXP’s BSPs.

Regards,

[dluberger]

I'd be more apt to use yocto if there were any concise or straightforward documentation but all of the documentation is extremely abstract if not convoluted. I just can't seem to figure out how to do anything, and i cant find any instructions on how to do what i need to do, which is simply to get my board up and running with something like x11/xorg and mono. i dont even need a desktop except to have something to test my touchscreen.  i tried making core-image-sato but i get endless errors trying to boot and im sure its because i havent customized the device tree or kernel but the yocto guide doesnt even say how to do that and that seems to be the least of what anyone would need to do.  are there any decent guides that you know of for bringing up a custom board? in my case the hardware is very simple with few peripherals but otherwise very similar to the imx6ull evk.