Boot custom Linux image using PXE

Is it possible to boot a client over PXE using custom Linux image using PXELINUX? **Background** > We use various IoT devices (Intel based processor) that use Linux as OS (Ubuntu to be > specific). But we have customized OS based on our need (for example by > adding our own applications, system configuration etc). Now, we are > looking into possibility if we can boot off these devices using PXE as > a fail-safe for local storage corruption (or just get away from that). > > I am able to achieve this using standard Ubuntu images using TFTPD64 > (on Windows) and PXELINUX. And I can selectively boot image for > different devices based on their MAC IDs. But I am having hard time > make it work for our image. So my question is, how can I create custom image (or use any other mean) to boot our Linux system using PXE? I created ISO using DD utility (over 4GB in size). But PXELINUX bootloader fails to even download that ISO.