CONFIG_NIOS2_DTB_AT_PHYS_ADDR is not available for thedefaultarchitecture x86.
Result is shown for architecture nios2

DTB at physical address


Linux Kernel Configuration
└─>Platform options
└─>DTB at physical address
In linux kernel since version 3.19 (release Date: 2015-02-08)  
When enabled you can select a physical address to load the dtb from.
Normally this address is passed by a bootloader such as u-boot but
using this you can use a devicetree without a bootloader.
This way you can store a devicetree in NOR flash or an onchip rom.
Please note that this address is used directly so you have to manually
do address translation if it's connected to a bridge. Also take into
account that when using an MMU you'd have to ad 0xC0000000 to your