Now I feel the difference and hope I will use that names correctly :) Thank you for that clarification. I try to use Angstrom with Beagleboard and I can do all that necessary actions to have rootfs files on SD card. It works with kernel provided with Angstrom. That online builder creates uImage in /boot directory.
I also tried to run Angstrom with kernel provided by Texas Instruments, compiled on my own with CodeSourcery toolchain and it also started. I have found only couple of mentions that people use it this way, but I wonder what is the limit, what I should take care of with matching kernel and rootfs. E.g. here is nice workflow (thanks Maxym Parkachov) http://veter-project.blogspot.com/2012/03/comfortable-kernel-workflow-on.html. He just takes that two things. W dniu niedziela, 13 stycznia 2013 13:03:38 UTC+1 użytkownik Peter Teoh napisał: > > Perhaps more links to clarify the "dd" concept (just try to search for > "dd" and understand what it does): > > http://downloads.angstrom-distribution.org/demo/beaglebone/mkcard.txt > > http://www.angstrom-distribution.org/ipaq-h2200-series > > http://downloads.angstrom-distribution.org/demo/beaglebone/ > > In above (beaglebone), notice that the rootfs.tgz is also just a > collection of files, and it is necessary to untar it into a actual SD > card, which is formatted as ext3. > > I hope u are clarified with the concept now. Sorry if I may be wrong > in any way - in particular to the way term "rootfs" is used, but > conceptually all my description are correct. > > Ie, "rootfs" meant to me: harddisk image of all the files starting > at the root level. But many sites/people seemed to create it as a > collection of files with no filesystem involved. Does not matter, > but hope u understand these. > > > On Jan 13, 7:51 pm, Peter Teoh <[email protected]> wrote: > > wow, this site is cool, I have done these manually before, but > > amazingly they can automate it, and for so many different boards. > > > > This site has a problem, but let me describe to you what is a > > "rootfs": > > > > Conceptually, it is supposed to be literally (or identical to) a > > harddisk containing your entire filesystem, starting from "/" root > > level. Just like that. > > > > So how to do that? Basically it is a "dd" image (i hope u understand > > "dd" command - almost all image making utilities is some form of > > "dd". and another word for "dd" is "mirror copy of the harddisk, > > bytes for bytes") of the harddisk, and thereafter redirected the > > output to a file. So the recipient when it open the file, and > > attempt to read it, he will not be able to different any differences > > (yes, byte for byte, zero differences, which is why "dd" is also used > > in computer forensics to make a duplicate copy of the harddisk) > > between the two. > > > > so when u run your qemu, then u feed the file as "rootfs", to simulate > > the a virtual harddisk. > > > > and as for actual "filesystem"? there is no mentions....the way the > > bytes are organized....that is filesystem. and u need kernel to read > > that. (of course there is also userspace tool to read filesystem - > > normally only for readonly operation, and if write operation is > > allowed, then u need to ensure no way of collision). > > > > well....too much to say....the site (http://narcissus.angstrom- > > distribution.org/) what it does is collects all the files needed > > together, and that tgz it into a file for you to download. > > > > That is just a collection of files, no filesystem involved. > > > > U now have to use "dd" to make a image, then "mkfs" to make a > > filesystem on the image file, then mount it writeable, as a directory, > > and then "tar xvf" the file u have gotten fromhttp:// > narcissus.angstrom-distribution.org/ > > into that directory. Now umount the directory, and u have a real > > rootfs!!!! > > > > For example: (just a random pick) > http://www.phidgets.com/phorum/viewtopic.php?f=39&t=5090 > > > > Here is a rootfs formatted as jffs2 filesystem. > > > > That is the one u should use for qemu. > > > > But if u have a thumbdrive, just format that thumbdrive as jffs2 > > direct, and mount it, and "tar xvf" all the files as per generated for > > you, and u have "rootfs" on the thumbdrive. > > > > On Jan 12, 5:16 am, "Valdez V." <[email protected]> wrote: > > > > > > > > > > > > > > > > > Thank you. So if there is such an online builder for rootfs, > http://narcissus.angstrom-distribution.org/howpeople prepare kernel for > > > it? Do you know? > > > > > W dniu piątek, 11 stycznia 2013 05:11:46 UTC+1 użytkownik Peter Teoh > > > napisał: > > > > > > kernel and filesystem are highly integrated, the reason is simply > > > > because filesystem are using kernel API to talk to the kernel. and > > > > because of these use of kernel API, the version of kernel used > matters > > > > (eg, porting filesystem from Angstrom to Davinci etc). In short, > > > > porting work is no mean task. best is to stick to the available FS > > > > in each distro...if u want u can port and submit as patches to the > > > > distro...and others will test it out for you. > > > > > > On Jan 10, 5:29 am, "Valdez V." <[email protected]> wrote: > > > > > Hello, > > > > > > > I have question about relation between kernel and some distro > > > > filesystem. I ask because e.g. I need to use some specific kernel, I > > > > download it from OMAP kernel sources and then I need filesystem for > it. > > > > > Can I just use filesystem of Angstrom, Ubuntu... or I should adapt > is > > > > somehow? > > > > > > > Best regards, > > > > > Valdez >
