* [U-Boot] where is the crc stored? @ 2012-12-21 18:32 John Stile 2012-12-21 19:54 ` Wolfgang Denk 0 siblings, 1 reply; 4+ messages in thread From: John Stile @ 2012-12-21 18:32 UTC (permalink / raw) To: u-boot What area of memory is the crc stored for a partition? I would like to find some detailed documentation on the crc (how big is it, where it is stored, how to invalidate to force the booting from a second area). ^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot] where is the crc stored? 2012-12-21 18:32 [U-Boot] where is the crc stored? John Stile @ 2012-12-21 19:54 ` Wolfgang Denk 2012-12-21 21:27 ` John Stile 0 siblings, 1 reply; 4+ messages in thread From: Wolfgang Denk @ 2012-12-21 19:54 UTC (permalink / raw) To: u-boot Dear John Stile, In message <1356114777.28896.92.camel@genx> you wrote: > What area of memory is the crc stored for a partition? Which sort of partitions are you talking here? > I would like to find some detailed documentation on the crc (how big is > it, where it is stored, how to invalidate to force the booting from a > second area). In general, erasing the whole region will usually work ;-) 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 Q: Why do mountain climbers rope themselves together? A: To prevent the sensible ones from going home. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot] where is the crc stored? 2012-12-21 19:54 ` Wolfgang Denk @ 2012-12-21 21:27 ` John Stile 2012-12-21 23:09 ` Wolfgang Denk 0 siblings, 1 reply; 4+ messages in thread From: John Stile @ 2012-12-21 21:27 UTC (permalink / raw) To: u-boot On Fri, 2012-12-21 at 20:54 +0100, Wolfgang Denk wrote: > Dear John Stile, > > In message <1356114777.28896.92.camel@genx> you wrote: > > What area of memory is the crc stored for a partition? > > Which sort of partitions are you talking here? Maybe partition is the wrong word for a memory address region. I am a total new-bee, but I have read there is a crc check in u-boot. The crc check can result in a: Warning: Bad CRC, using default environment The crc is considered during the bootcmd. > > I would like to find some detailed documentation on the crc (how big is > > it, where it is stored, how to invalidate to force the booting from a > > second area). > > In general, erasing the whole region will usually work ;-) > > Best regards, > > Wolfgang Denk > I would like to know where this crc is stored. I would like to know is it 8-bit, 16-bit, and 32-bit, or other. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot] where is the crc stored? 2012-12-21 21:27 ` John Stile @ 2012-12-21 23:09 ` Wolfgang Denk 0 siblings, 0 replies; 4+ messages in thread From: Wolfgang Denk @ 2012-12-21 23:09 UTC (permalink / raw) To: u-boot Dear John Stile, In message <1356125251.28896.119.camel@genx> you wrote: > > I am a total new-bee, but I have read there is a crc check in u-boot. Actually there are several such checks, for several different purposes. > The crc check can result in a: > Warning: Bad CRC, using default environment THis is when checking if there is a valid environment. So we are talkign about the CRC which protects the persistent environment copy. The structure of this is defined in "include/environment.h", see struct environment_s - as you can see, this is a CRC32. > The crc is considered during the bootcmd. No, this has absolutely nothing to do with bootcmd. > I would like to know where this crc is stored. In the first 4 bytes of the external representation of the environment. > I would like to know is it 8-bit, 16-bit, and 32-bit, or other. 32 bit. 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 The ultimate barrier is one's viewpoint. - Terry Pratchett, _The Dark Side of the Sun_ ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-12-21 23:09 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-12-21 18:32 [U-Boot] where is the crc stored? John Stile 2012-12-21 19:54 ` Wolfgang Denk 2012-12-21 21:27 ` John Stile 2012-12-21 23:09 ` Wolfgang Denk
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