u-boot-2014.10 26th day----NAND flash start (iv)

Hardware platform: tq2440

Development environment: Ubuntu-3.11

U-boot version: 2014.10

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u-boot-2014 whether you start from nor flash or NAND flash, it calculates the location of the U-boot being redirected based on the SDRAM space, as nor Flash can operate like SDRAM. The code can run directly in nor flash, so redirection is easy to implement for it. However, NAND Flash does not operate directly like SDRAM, so it is necessary to first copy the U-boot to a location in the SDRAM in order to start from NAND flash, and then start from the new location and perform the redirect operation. In order to achieve the same code can not modify the implementation from NAND flash or nor flash boot, it is necessary u-boot self-judgment is currently launched from that Flash, convenient to copy U-boot to SDRAM, and then re-location.

u-boot-2014.10 26th day----NAND flash start (iv)