[U-Boot] about nand_read_byte() interface

[Scott Wood]

On Fri, Oct 30, 2009 at 01:20:58PM +0800, HeLei wrote:
> 
> Hi, all

Hi, please wrap your lines at 75 or so characters -- and definitely don't
paste code as all one line.

> I'm a little confused on NAND read operation. 
> According to NAND character, NAND flash is read page by page, which mean's
> once you read, at least you should read data with page size (such as
> 512Bytes)

Yes, unless you're reading from the out-of-band area.

> But the nand_read_byte() is implemented as following:	static u_char
> nand_read_byte(struct mtd_info *mtd) { struct nand_chip *this = mtd->priv; return readb(this->IO_ADDR_R); }
> it seems only one byte is read out.

It's reading one byte out of a buffer that was previously filled with some
operation.  It is used for reading status bytes and OOB bad block markers.

-Scott