Summary of Linux U-boot tracking methods

Get a board, one of the most important thing is to see the circuit diagram and datasheet.

This is really important, first you need to know what the CPU architecture is, ARMV7?ARVMV5, or other, which company's chip? is Freescale or Ti or MTK, or samsung,hisilicon or some other what chip, now the CPU data manuals are all relatively full, it is easy to find relevant information on the official website, but also to find some other useful information on the official website, For example, the official for the chip has no evaluation board, for the board has a system of support, related tools, such as writing system tools, are very useful.

In fact, an embedded product, in addition to the initial product planning when planning the function of the CPU has been to this product has been fixed type.

Take a look at the tracking method for a product u-boot today.

Purely personal soil method, not correct to point out.

1. If the board has been given a set of systems to you, determined the correct way to burn, to determine the correct sysboot. Then you can start tracking u-boot, in the previous essays have some records, but also is not very mature and easy to understand, today to talk about a more vulgar tracking method.

First, determine the correct configuration of your makefile, configure this u-boot once, and then compile it successfully once.

Take the previous tiny4412 that board, u-boot the correct configuration is make Tiny4412_config Make-j8 compiled successfully.

He will generate several important files, U-boot.bin, u-boot.lds the first is the compiled binary, and the second is the compiled link script.

The place where we started was u-boot.lds.

This will specify the starting position of the u-boot, for a simple analogy, if your CPU is the ARMV7 architecture, then your starting position in all likelihood is arch/arm/cpu/armv7/start. S

Don't ask me why, this is experience. But the above situation also has special circumstances, specifically to see U-boot.lds, if not really can see this file there is no START.O file, there is.

My u-boot.lds is.

1 . Text:2  {                                                                              3arch/arm/cpu/armv7/start.o (. Text)4board/samsung/tiny4412/libtiny4412.o (. Text)5arch/arm/cpu/armv7/exynos/libexynos.o (. Text)6*(. Text)7}

This means that my starting position is just that, and the second one is down below.

The document also stipulates that the entrance is (_start)

Next is _start reset Cpu_init_crit board_init_f relocate_code board_init_r Main_loop anyway that's the way it goes, if you're not sure this article Whether you want to go in, then search the file of the. o file, if so, generally speaking, but also to see the include/configs/********.h file, this file I also introduced in the previous.

If you do not know the various file structures of U-boot, look at the top-level file Readme should have some introduction.

　　

Summary of Linux U-boot tracking methods