On Wed, Mar 15, 2023, at 08:28, Jacky Huang wrote: > + mem: memory@80000000 { > + device_type = "memory"; > + reg = <0x00000000 0x80000000 0 0x20000000>; /* 512M DRAM */ > + }; > +}; In most machines, the memory size is detected by the boot loader and filled in the dtb in memory before starting the kernel, so you should not need two separate files here for the two common memory configurations. Since the machine is called 'som', I would assume that this is a module that is integrated on another board, so more commonly one would have a dtsi file for the som in addition to the one for the soc, and have all the components of the module listed in this file, while the dts file that includes the som.dtsi lists the devices on the carrier board and enables the on-chip devices that are connected to the outside. Arnd