Dear =?ISO-8859-1?Q?Matthias_Wei=DFer?=, In message <4c63aca6.6080...@arcor.de> you wrote: > Am 12.08.2010 09:54, schrieb Frans Meulenbroeks: > > 2010/8/12 Matthias Weißer<weiss...@arcor.de>: > >> Why not store the size of the environment sector as env variable? The size > >> should be only needed for storing the environment and not for loading (as > >> it > >> is terminated by a '\0'). So we could load the environment, check for > >> "env_size" and if its not there take the value from fw_env.config > > > > Currently the crc of the environment is calculated and if it does not > > match with the stored crc the default environment is used. > > For determining the crc the size is needed so storing the size in the > > env creates some form of catch-22. Of course the code could be > > modified to first peek at the unverified env to find the size. > > That is a different approach. Imho not too neat.
Was this an off-list reply? I cannot see any trace of this message on the list. Please always keep the list on Cc: ! > I see. I was thinking that the CRC is only calculated over the > environment until the '\0' end mark is reached. But after checking my > environment code I see that the CRC is calculated over the whole sector. For the sake of simplicity it should be possible to assume that the CRC is correct, look up the env_size variable, and then check the CRC with the length thus found. > > Wrt the format: I understood from the mail from Reinhard that the way > > the env is stored is going to change anyway. I saw the patches of > > Wolfgang pass by, but didn't have time to study them yet. The external storage format will NOT change. Compatibility with existing code (not only in U-Boot) is a major concern of all such changes. > I also didn't go that deep into Wolfgangs patches but from what I > understand the "on disk format" will not change. Will it? No, it ill remain exactly the same. > Maybe the size could be added at the end of the environment (behind the > '\0'). So we wouldn't loose compatibility. It would add new issues, like when the envrionment is filing up. 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: w...@denx.de Change is the essential process of all existence. -- Spock, "Let That Be Your Last Battlefield", stardate 5730.2 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot