Jocke, you are so kind.Thank you very much:)
Subject: RE: [U-Boot] Does uboot EBS(erase block summary) to reduce JFFS2 scaning time? To: leon.he@msn.com CC: u-boot@lists.denx.de From: joakim.tjernlund@transmode.se Date: Tue, 3 Nov 2009 10:20:19 +0100
HeLei leon.he@msn.com wrote on 03/11/2009 09:21:04:
Thank you, Jocke
Subject: Re: [U-Boot] Does uboot EBS(erase block summary) to reduce JFFS2
scaning time?
To: leon.he@msn.com CC: u-boot@lists.denx.de From: joakim.tjernlund@transmode.se Date: Tue, 3 Nov 2009 08:41:08 +0100
Hi, All
Each time JFFS2 initialized, uboot need to scan the whole flash. This is fairly time consuming.
So EBS(erase block summary) is used to JFFS2 to reduce mounting time. And I believe this can also be used to UBOOT to reduce booting time.
Does UBOOT support this feature? or does any other solution in uboot to reduce JFFS2 scaning time?
Don't think EBS is going to buy you much. The main problem is that the
You mean even EBS is used in UBOOT, it will not give me much help. But it seems there is great efficiency in jffs2 mounting, from some artical in internet, such as:http://www.embedded-linux.co.uk/tutorial/jffs2-summary
scanning of JFFS2 in u-boot is inefficient. u-boot could take a hint from the kernel impl. of JFFS2 to reduce scanning. The biggest ones are:
- do no scan the whole EB when it is empty.
If we don't scan the block, how can we tell the EB is empty?
- impl. a better crc32(use the one from linux)
Attaching a very crude port of linux crc32. This boots a linux img for me and handles the environment crc as well. Feel free to clean it up and submit to u-boot.
Jocke (See attached file: crc32-new.c)(See attached file: crc32defs.h)(See attached file: crc32table.h)
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