[U-Boot-Users] make env

Wolfgang Denk wd at denx.de
Wed Apr 2 12:39:50 CEST 2008


Dear Manuel,

in message <47F3528A.3000202 at feig.de> you wrote:
> 
> My problem the structure of the enviroment:
> If I understand:
> 4 byte crc; 1 byte flags, 0x20000-5 byte data.

Correct - the flag byte is only present if you use redundant
environment.

> The CRC is over the data bytes,( not the flags byte included) , right ??

Correct. That's because the flasg byte indicates  the  state  of  the
environment  copy  (current  ->  bit = 1, or obsolete -> bit = 0). It
relies on the feature of NOR flash that you can  always  program  '1'
bits to '0', even single bits in a single byte.

> What about the flag byte, which values should I have to write here ?

See above. But you might have problems doing such  a  thing  on  NAND
storage.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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