Before analyzing the source U-Boot, first understand the compilation process of uboot
surroundings:
Development Board: friendliness arm JZ2440, master: S3C2440 ARM920t
Uboot Source Package: u-boot-1.1.6
First, unpack, patch
Second, placement
By reading the top README to understand Uboot configuration and compilation is a good method.
Found, to use the boards board / <board name>, must be executed "make <board name> _config" configuration command, then execute make, the following documents can be generated
.Bin file which can be directly burned into ROM, the burn-in operation, you can start to see the serial output information, and enter the control interface.
Before transplanting Uboot, you can look make <board name> _config command and make the command do something in order to understand the flow of the program, in order to know which files need to be modified.
After (compiled Uboot successful, it will be generated in the tools subdirectory of some tools, such as mkimage like to copy it to / usr / local / bin directory mkimage ,, you can use to generate the kernel image file format Uboot uimage)
make 100ask24x0_config
Then it analyzes make 100ask24x0_config "instruction is how to achieve chip selection.