topic Re: Regarding the Partition on the SD Card in i.MX Processors

Regarding the Partition on the SD Card

KrishnaPavan — Thu, 20 Oct 2011 10:40:21 GMT

user@ACN:~/ltib/ltib/rootfs/boot$ sudo fdisk /dev/sdb

Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x5d2fa167.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): u
Changing display/entry units to sectors

Command (m for help): d
No partition is defined yet!

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First sector (62-7744511, default 62): 8192
Last sector, +sectors or +size{K,M,G} (8192-7744511, default 7744511):
Using default value 7744511

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.

Highlighted lines are those where I need some inferences

Re: Regarding the Partition on the SD Card

VladanJovanovic — Thu, 20 Oct 2011 11:12:54 GMT

Looks like it is in use somehow. So unmount it first before running fdisk on it:

sudo umount /dev/sdb*

Re: Regarding the Partition on the SD Card

daiane_angolini — Thu, 20 Oct 2011 14:19:08 GMT

your SDCard MBR looks like being corrupted.

If you´re getting trouble using fdisk (I absolutly get confused with it), please use gparted (I use this because I don´t like to count blocks)

Take a look here http://imxcommunity.org/xn/detail/4103961:Comment:23615 to see how I use gparted.

First of all, create the MBR again. So, create any partition you want.

And don´t forget SDCard is (for linux booting):

first 512 -> MBR

at 1K -> bootloarder

at 1M -> uImage

Re: Regarding the Partition on the SD Card

KrishnaPavan — Thu, 20 Oct 2011 14:28:48 GMT

Thank You,Daiane..... Thats exactly is the answer I require Daiane.

But, I dont know the partition scheme.

I have tried this with the gparted and am attaching an image,

I want to use and place my u-boot.bin and uImage in the locations you have specified, for that I gave partition 1, a size of 4 MB, using sudo fdisk /dev/sdb the sequence next being u d n p 1 8192 Enter w against command(m for help): prompt.

I ran the steps according to linux-3DStack guide and copied all the supporting files to SD Card, But, there is no boot because the 4MB has to be filled with the u-boot.bin & uImage which in my case has not happened.

Regards::: Krishna Pavan

Re: Regarding the Partition on the SD Card

daiane_angolini — Thu, 20 Oct 2011 14:34:14 GMT

I always give first partition 20 M, How big is your uImage? Please, double check it.

And I always format second partition. You choose the file system (ext2, ext3, ext4, vfat, whatever one kernel recognizes)

and I copy the u-boot-noparding.bin using this command line:

$ sudo dd if=u-boot-no-padding.bin of=/dev/sdX bs=1K seek=1

And for uImage I use this command line:

$ sudo dd if=uImage of=/dev/sdX bs=1M seek=1

What are you using? Please, paste over here the log.