[U-Boot] [U-boot] question about nand_scan_bbt()

[TigerLiu at via-alliance.com]

Hi, Scott:

I have a question about nand_scan_bbt() function in
drivers/mtd/nand/nand_bbt.c .

         ......

         len = (1 << this->bbt_erase_shift); // bbt_erase_shift = 18
(256KB)

         len += (len >> this->page_shift) * mtd->oobsize;

         buf = vmalloc(len);

         ......

 

Why does it need to allocate "1 block size + all pages' oob size in this
block" .

It seems other functions called in nand_scan_bbt() only needs a small
buf ("one page size + its oob size").

 

Best wishes,