Directory hierarchy

Directory path	Usage
/arch	Architecture-specific files
/arch/arc	Files relating to ARC architecture
/arch/arm	Files relating to ARM architecture
/arch/m68k	Files relating to m68k architecture
/arch/microblaze	Files relating to microblaze architecture
/arch/mips	Files relating to MIPS architecture
/arch/nios2	Files relating to Altera NIOS2 architecture
/arch/powerpc	Files relating to PowerPC architecture
/arch/riscv	Files relating to RISC-V architecture
/arch/sandbox	Files relating to HW-independent “sandbox”
/arch/sh	Files relating to SH architecture
/arch/x86	Files relating to x86 architecture
/arch/xtensa	Files relating to Xtensa architecture
/api	Machine/arch-independent API for external apps
/board	Board-dependent files
/boot	Support for images and booting
/cmd	U-Boot commands functions
/common	Misc architecture-independent functions
/configs	Board default configuration files
/disk	Code for disk drive partition handling
/doc	Documentation (a mix of ReST and READMEs)
/drivers	Device drivers
/dts	Makefile for building internal U-Boot fdt.
/env	Environment support
/examples	Example code for standalone applications, etc.
/fs	Filesystem code (cramfs, ext2, jffs2, etc.)
/include	Header Files
/lib	Library routines relating to all architectures
/Licenses	Various license files
/net	Networking code
/post	Power On Self Test
/scripts	Various build scripts and Makefiles
/test	Various unit test files
/tools	Tools to build and sign FIT images, etc.