[U-Boot] U-boot doubts
Wolfgang Denk
wd at denx.de
Thu Dec 17 07:38:28 CET 2009
Dear Chandra Sekar,
In message <67b11d980912162018j3febe826l91c6b52134123d37 at mail.gmail.com> you wrote:
>
> why do we have two files(env_nand.c and env_flash.c) to manipulate
> environmental variables?
Because NAND flahrequires diofferent handling than NOR flash.
Note there is also common/env_dataflash.c, common/env_eeprom.c,
common/env_mgdisk.c, common/env_nowhere.c, common/env_nvram.c,
common/env_onenand.c, and common/env_sf.c
> According to my knowledge nand is also a flash type then why we have
> separate file called env_flash.c or is this file will be used for nor flash?
NOR flash is a memory device which is byte-addressable by the
processor. NAND flash is no memory, but a storage device instead,
which needs to be read in buffers into RAM before you can access
arbitrary bytes of it's content.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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