UBootCmdGroupNand < DULG

%SECTION0{name=UBootCmdNand}% NAND devices

U-Boot allows us to directly work with NAND devices attached directly
or through a NAND controller.  The commands are grouped under the
=nand= subsystem:

%INCLUDE{DULGData_%BOARD%.UBootNandHelp}%

%SECTION1{name=UBootNandBad}% nand bad - show bad block information

As NAND devices can develop bad blocks over their lifetime and usually
even are delivered with bad blocks already, the NAND commands need to
be aware of this fact.  Getting information of the current bad block
list is easy:

%INCLUDE{DULGData_%BOARD%.UBootNandBad}%

%SECTION1{name=UBootNandErase}% nand erase - erase region

Ensuring that the NAND device functions properly, we will use the
basic commands to construct a testpattern in memory, write that to the
device, of course erasing it first, and read the data back.  A final
comparison will show if all data was transferred correctly.

We begin be erasing 64k at the start of the NAND device:

%INCLUDE{DULGData_%BOARD%.UBootNandErase}%

%SECTION1{name=UBootNandWrite}% nand write - write to NAND device

Let's create a testpattern in memory and write that to the previously
erased NAND area:

%INCLUDE{DULGData_%BOARD%.UBootNandWrite}%

%SECTION1{name=UBootNandRead}% nand read - read from NAND device

As everything worked ok, we ensure everything was fine by transferring
the data to a different location in RAM and check this against the
original written content:

%INCLUDE{DULGData_%BOARD%.UBootNandRead}%