[U-Boot-Users] dd to generate image.
Hi, I'm using dd to generate the u-boot+kernel+rootfs image. I executed command like.. dd if=rootfs.jffs2 of=kernel.img bs=1 seek=ROOTFS_OFFSET But dd is quite slow, generating a 64MB image spends about 5 minutes. I have changed bs=1 to bs=1024 or bigger, but the outputted image size is wrong, too big. dd manpage says that bs is the size of read/write one time. Doesn't it make dd faster?
How do make dd faster?
2008/3/14, Tim Chen tim.chen.86@gmail.com:
Hi, I'm using dd to generate the u-boot+kernel+rootfs image. I executed command like.. dd if=rootfs.jffs2 of=kernel.img bs=1 seek=ROOTFS_OFFSET But dd is quite slow, generating a 64MB image spends about 5 minutes. I have changed bs=1 to bs=1024 or bigger, but the outputted image size is wrong, too big.
try dd if=rootfs.jffs2 of=kernel.img bs=ROOTFS_OFFSET seek=1
(bs is the block size and seek is counted in block size)
-- Richard Genoud - Adeneo
In message 9c1eb1b90803140101t79d577ddsa396573307b1ce21@mail.gmail.com you wrote:
I'm using dd to generate the u-boot+kernel+rootfs image. I executed command like.. dd if=rootfs.jffs2 of=kernel.img bs=1 seek=ROOTFS_OFFSET But dd is quite slow, generating a 64MB image spends about 5 minutes.
Hm... you must be on a very slow machine, then.
I have changed bs=1 to bs=1024 or bigger, but the outputted image size is wrong, too big.
Perhaps you forgot that "seek" is counting in units of "bs"; i.e. if you change from "bs=1" to "bs=1024" you also have to change from "seek=ROOTFS_OFFSET" to "seek=$(expr ROOTFS_OFFSET / 1024)"
dd manpage says that bs is the size of read/write one time. Doesn't it make dd faster?
Yes, it does.
How do make dd faster?
See above.
Best regards,
Wolfgang Denk
Thanks, my problem fixed.
On Fri, Mar 14, 2008 at 11:24 PM, Wolfgang Denk wd@denx.de wrote:
In message 9c1eb1b90803140101t79d577ddsa396573307b1ce21@mail.gmail.com you wrote:
I'm using dd to generate the u-boot+kernel+rootfs image.
participants (3)
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Richard Genoud -
Tim Chen -
Wolfgang Denk