Bootloader-u-boot learning.

Bootleader is a program that starts to execute when the system is powered on. It initializes the hardware device, prepares the software environment, and finally calls the operating system kernel.

U-boot is a general boot program suitable for multiple CPUs. Multiple operating systems can be guided to support CPUs with multiple architectures.

U-boot source code structure:

File structure:

Board: Related to the Development Board. Board corresponding to different configurations

CPU: corresponding to different CPUs. For example, there is at91rm9200 at ARM920T.

Lib_i386 is similar to a common file in a certain architecture.

Include: the general function header file and the development board configuration file. Include/config contains the development board configuration file.

Lib_generic common library functions

Conmon: A common function that further encapsulates the driver at the next layer.

Disk: hard disk interface program

Drivers: drivers for various devices.

DTT: the drive of a Digital Thermostat or sensor

FS: filesystem: File System

Nand_spl: U-boot is generally started from Rom, romflash, and other devices. Now it starts from NAND Flash,

Net: various network protocols

Post: power-on self-check program

RTC: Real-time clock driver

Doc documentation, user documentation

Examples: Some test programs can be downloaded and run using U-boot.

Tools: tools used to create an image in the S-record and U-boot formats

[... Under preparation] For the embedded part, see zisu123.sinaapp.com.

Reference: complete embedded Linux application development manual Wei Dongshan.