* Different erase block sizes in a JFFS2 partion. @ 2006-09-28 21:55 Joakim Tjernlund 2006-09-28 23:07 ` Josh Boyer 0 siblings, 1 reply; 3+ messages in thread From: Joakim Tjernlund @ 2006-09-28 21:55 UTC (permalink / raw) To: linux-mtd Got multiple NOR chips with top and bottom boot blocks with diffrent EB size then the rest of the blocks. I want to put a JFFS2 FS spanning over several chips which makes the FS cross top/bottom boot blocks. Since(last I looked) JFFS2 can't deal with diffrent EB sizes on the same partition I need do something about it. I want to use point()/unpoint() and a cached memory mapping for burst access and I don't know how to do that yet and I would like some ideas. One idea I have is to reserve the boot blocks with a new type of JFFS2 node(similar to JFFS2_FEATURE_ROCOMPAT) that spans the whole boot block. JFFS2 should not try to move or delete nodes of this type. Not sure if thats a good idea or if its hard to impl. yet. Better ideas anyone? ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Different erase block sizes in a JFFS2 partion. 2006-09-28 21:55 Different erase block sizes in a JFFS2 partion Joakim Tjernlund @ 2006-09-28 23:07 ` Josh Boyer 2006-09-29 6:43 ` Joakim Tjernlund 0 siblings, 1 reply; 3+ messages in thread From: Josh Boyer @ 2006-09-28 23:07 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: linux-mtd On 9/28/06, Joakim Tjernlund <joakim.tjernlund@transmode.se> wrote: > Got multiple NOR chips with top and bottom boot blocks with diffrent EB size > then the rest of the blocks. Intel P30? IIRC, the MTD driver maps those into a set of larger virtual eraseblocks. You might not be able to even distinguish that they exist. josh ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Different erase block sizes in a JFFS2 partion. 2006-09-28 23:07 ` Josh Boyer @ 2006-09-29 6:43 ` Joakim Tjernlund 0 siblings, 0 replies; 3+ messages in thread From: Joakim Tjernlund @ 2006-09-29 6:43 UTC (permalink / raw) To: Josh Boyer; +Cc: linux-mtd Josh Boyer wrote: > On 9/28/06, Joakim Tjernlund <joakim.tjernlund@transmode.se> wrote: >> Got multiple NOR chips with top and bottom boot blocks with diffrent EB size >> then the rest of the blocks. > > Intel P30? IIRC, the MTD driver maps those into a set of larger > virtual eraseblocks. You might not be able to even distinguish that > they exist. yes, Intel P30. The cfi_cmdset_0001 driver maps them like this: 0: offset=0x0,size=0x8000,blocks=4 1: offset=0x20000,size=0x20000,blocks=255 2: offset=0x2000000,size=0x8000,blocks=4 3: offset=0x2020000,size=0x20000,blocks=255 First, this map is wrong. 2: and 3: should be swapped, that is, the small blocks should be at the end of the device. the small blocks fits into a larger one so I should have no problem reading/writing to such virtual block, but I don't think erase will work as JFFS2 will only erase one of the small blocks instead of all 4. Maybe I am missing something? ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2006-09-29 6:43 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2006-09-28 21:55 Different erase block sizes in a JFFS2 partion Joakim Tjernlund 2006-09-28 23:07 ` Josh Boyer 2006-09-29 6:43 ` Joakim Tjernlund
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