Introduction - If you have any usage issues, please Google them yourself
U-Boot first phase of the startup process. (second stage nandflash start, NAND 4K code to test SRAM, because NAND did not address line, cannot be mapped into memory, so through the SRAM 4K code in SRAM over the whole uboot copy to the SDRAM, a good initialization stack, provide the conditions for the C language into uboot! This stage is mainly to initialize hardware devices, to prepare RAM space for loading the U-Boot's second stage code, and finally jump to start_armboot function in lib_arm/board.c, which is the entry point of the second stage.