Hi Onzen, Any luck in the GPIO solution when trying to mount the root filesystem as read-only? I am also considering to put the whole of the rootfs as readonly but just like you I am also using the GPIO via the normal write(), read() operations.
I apologize that I digged up such an old post, but I would like to know if you have solved the problem since. On Wednesday, December 5, 2012 5:08:46 PM UTC+8, özen özkaya wrote: > > This is really a very smart scenario Rico. I will also follow that :) > > Read only filesystem gives a solid solution across corruptions. But on the > other side I have faced a problem with writing GPIO's. Because all the root > filesystem is read only, I can not write GPIO states. This is a very bad > problem for functionality an today I am digging about how to change GPIO > state. If I find a solution, I will write it here. > > Thank you for all! > Have a nice day > > Regards > Özen > > 2012/12/5 Rico <[email protected] <javascript:>> > >> Hello Özen, >> >> thats exactly what I did :) >> I^ve created another partition on the sd card and mount that rw to have >> non-volatile memory, that works very well. Beside of that, I have a tool on >> the read-only filesystem that tries to mount the rw partition and tries to >> start my application, which is on the rw partition. If this fails, I format >> the rw partition from within that tool and start a backup tool which is >> located on the ro partition as well. >> >> On Tuesday, 4 December 2012 13:53:01 UTC+1, Özen Özkaya wrote: >> >>> Hi Rico, >>> >>> I am really really proud of you. Thank you! >>> In the current case I have followed your instructions and get my rootfs >>> read-only. Thank you again and again. >>> >>> As you mentioned my home folder is also read only and I have no >>> non-volotile writable memory region left but I have a plan. >>> In the current case I have two memory regions (boot and rootfs). I will >>> make three memory regions (boot,rootfs,data) >>> The third memory region(data) will be mounted as rw. Hence I will get a >>> non-volatile writable region also. I think this will work. >>> >>> Thank you for all Rico! >>> >>> Regards. >>> >>> >>> 2012/12/4 Rico <[email protected]> >>> >>> Hi Özen >>>> >>>> 1) In the bootloader, you have to mount the partition that contains >>>> your filesystem ro, but that was already the case in my bootlader so I did >>>> not have to change that. >>>> 2) In /lib/systemd/system/remount-rootfs.service I just commented out >>>> the the line that starts with "ExecStart" so the root filesystem does not >>>> get remounted as rw >>>> 3) in fstab, you dont have to change the rootfs entry, but you have to >>>> make sure that fstab contains these two lines: >>>> >>>> tmpfs /tmp tmpfs >>>> defaults 0 0 >>>> tmpfs /var/run tmpfs >>>> defaults 0 0 >>>> >>>> By the way, that works for the console image of Angstrom, if you're >>>> using the image containing gnome, this might not working. >>>> Of course, your home folder is now read only too and you cannot store >>>> data in there. >>>> >>>> On Tuesday, 4 December 2012 09:25:28 UTC+1, Özen Özkaya wrote: >>>> >>>>> Hi Dear Rico and Fred, >>>>> >>>>> Firstly, I am really thankful for your responses. This short ideas >>>>> gave me lots of insights. >>>>> I am using the standard SD cards sent by cicuitco. They are Kingston >>>>> Class4 SD card. >>>>> >>>>> I am using standard Angstrom distribution's filesystem. Corruption >>>>> occures in rootfs side. >>>>> >>>>> In my application, there is a tcp/ip connection and an image >>>>> processing program (opencv). >>>>> Yesterday I found that I am saving a captured image to my >>>>> /home/root/Desktop directory for each 5 seconds. >>>>> Maybe it causes the over write and sdcard corruption. So I will save >>>>> the captured image to /dev/shm directory. >>>>> By the way I will keep my file in ram. I will review my project in the >>>>> manner of memory usage and then I will make tests. >>>>> >>>>> On the other hand, for Angstrom systems I think we have to achieve a >>>>> more stable filesystem. I am planning to >>>>> get read-only filesystem for both avoiding corruptions coming from >>>>> power issues and software issues. >>>>> >>>>> My error is like that: >>>>> [ 15.661254] mmcblk0: error -110 transferring data, sector 1802385, >>>>> nr 128, cmd response 0x900, card status 0x200b00 >>>>> [ 19.912536] mmcblk0: error -110 transferring data, sector 1802496, >>>>> nr 17, cmd response 0x900, card status 0x0 >>>>> [ 19.923004] end_request: I/O error, dev mmcblk0, sector 1802496 >>>>> >>>>> With the light of Rico's response I understand that, >>>>> >>>>> -> I have to change the bootargs of uboot to root=/dev/mmcblk0p1 ro >>>>> instead of rw >>>>> -> I have to find the service (rcX?) that remounts the filesystem to >>>>> r/w and I should remove that service >>>>> -> I have to change my /etc/fstab to mount /tmp and /var/run to mount >>>>> them as tmpfs >>>>> >>>>> Do I have to modify /etc/fstab to mount the filesystem read only? I >>>>> know how to modify it but whenever I modify it to mount filesystem >>>>> read only, it does not mount. Maybe it is because of the bootargs and >>>>> the service that change the fs to rw. >>>>> >>>>> Thank you for all, I will dig the problem. >>>>> >>>>> Regards, >>>>> Özen >>>>> >>>>> >>>>> >>>>> 2012/12/3 fred basset <[email protected]> >>>>> >>>>>> Hi Özen, >>>>>> >>>>>> Can you elaborate a bit more on your SD card corruption issue? What >>>>>> brand of cards are you using and what filesystem? Any ideas what >>>>>> triggered the corruption (e.g. sudden power fail). I am also >>>>>> concerned about this problem. >>>>>> >>>>>> TY, >>>>>> Fred >>>>>> >>>>>> On Mon, Dec 3, 2012 at 12:55 AM, Özen Özkaya <[email protected]> >>>>>> wrote: >>>>>> > Hello Dear Members, >>>>>> > >>>>>> > I have SD card corruption problems in my beaglebone. As a solution, >>>>>> I want >>>>>> > to set up read only filesystem. >>>>>> > I have read lots of documents and tried many things like editing >>>>>> fstab but I >>>>>> > could not get my current filesystem read only. >>>>>> > Firstly, is it possible to mount filesystem of Angstrom read-only? >>>>>> If yes >>>>>> > please can you just make suggestions about how to do it? >>>>>> > >>>>>> > I would be thankful if anyone makes suggestions about it. SD card >>>>>> corruption >>>>>> > becomed a nightmare for me. >>>>>> > >>>>>> > With thanks and regards >>>>>> > >>>>>> > -- >>>>>> > >>>>>> > >>>>>> >>>>>> -- >>>>>> >>>>>> >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>> >>>> >>>> >>> >>> >>> >>> >>> -- >> >> >> > > > > -- > Özen Özkaya > > R&D Vice Manager | Project Director > Teknotel Electronics > Address: Mimar Sinan Cad. No:6 > 34746 Yenisahra / Istanbul > Phone: +90 216 472 83 13 ext: 34 > Fax: +90 216 472 83 14 > E-mail: [email protected] <javascript:> > Web: http://www.teknotel.com.tr > > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
