Messages in this thread | | | Date | Thu, 31 Jul 2008 17:27:54 -0700 | From | "Nancy Isaac" <> | Subject | JFFS2 Questions |
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Please let me know if I have emailed the wrong group with these questions.
I have been working on bringing up an embedded system with 8313 processor, 128MB ram, 32MB NOR and 512MB NAND flash. We are using 2.6.21 kernel. We boot out of NOR using u-boot and program the NAND flash with jffs2 images for kernel and root file system. My first question is very basic. my rootfs.jffs2 image is 59MB when I create it using mkfs.jffs2 and do an ls -l on the file. What is the size of the image stored in the NAND flash? I have compression enabled, so I expected it to be still 50MB. When I do a du on the root file system after it's been mounted on the NAND flash, it shows the size as 114MB. I am wondering about the difference because I need to figure out how much space to allocate to accomodate an upgrade. Do I base it on the 59MB size or the 114MB size?
The second question is about the boot time. With the 59MB file system, it takes about 5 minutes to boot up and mount the file system. I know that JFFS2 is slower for boot up due to the scanning that happens at the beginning, but 5 minutes seems too long and makes me think I am doing something really wrong. I added printk time stamps to see if I can see where the time is being spent. It looks like the kernel bootup is pretty fast (30secs), but after I get to "Freeing unused kernel memory", it stays there for a long time with no output to the screen and then finally the init scripts start running and I get some output. Are there any other tools I can use to figure out what's going on at this time?
Thanks Nancy
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