LiteOS Cortex-A

/kernel/liteos_a
├── apps                   # User-space init and shell application programs
├── arch                   # System architecture, such as ARM
│   └── arm                # Code for ARM architecture
├── bsd                    # Code of the driver and adaptation layer module related to the FreeBSD, such as the USB module
├── compat                 # Kernel API compatibility
│   └── posix              # POSIX APIs
├── drivers                # Kernel drivers
│   └── char               # Character device
│       ├── mem            # Driver for accessing physical input/output (I/O) devices
│       ├── quickstart     # APIs for quick start of the system
│       ├── random         # Driver for random number generators
│       └── video          # Framework of the framebuffer driver
├── fs                     # File system module, which mainly derives from the NuttX open-source project
│   ├── fat                # FAT file system
│   ├── jffs2              # JFFS2 file system
│   ├── include            # Header files exposed externally
│   ├── nfs                # NFS file system
│   ├── proc               # proc file system
│   ├── ramfs              # RAMFS file system
│   └── vfs                # VFS layer
├── kernel                 # Kernel modules including the process, memory, and IPC modules
│   ├── base               # Basic kernel modules including the scheduling and memory modules
│   ├── common             # Common components used by the kernel
│   ├── extended           # Extended kernel modules including the dynamic loading, vDSO, and LiteIPC modules
│   ├── include            # Header files exposed externally
│   └── user               # Init process loading
├── lib                    # Kernel library
├── net                    # Network module, which mainly derives from the lwIP open-source project
├── platform               # Code for supporting different systems on a chip (SOCs), such as Hi3516D V300
│   ├── hw                 # Logic code related to clocks and interrupts
│   ├── include            # Header files exposed externally
│   └── uart               # Logic code related to the serial port
├── platform               # Code for supporting different systems on a chip (SOCs), such as Hi3516D V300
├── security               # Code related to security features, including process permission management and virtual ID mapping management
├── syscall                # System calling
└── tools                  # Building tools as well as related configuration and code