> > *Sorry that this is probably a dumb question, but is it possible to not > blow* > * away the partition table since I just want to swap the MLO and > u-boot.img?*
*Read everything below before half fast attempting such procedure* If I understand what you're asking here, yes it is possible. I've experimented with this personally. I talk about what I've done here in a blog post. http://www.embeddedhobbyist.com/2015/09/beaglebone-black-working-with-debianlinux-images/ So here is the idea. First you would want to backup the MBR liek this: $ sudo dd if=/dev/sdb of=/ home/william/mbr-sdb.bak bs=1M count=1 Second You write the wanted MLO / uboot.img file into the first 512k of the MBR. As demonstrated on Roberts eewiki guide - Which I think you linked to already ? That *should* leave the partition table intact. But in case it fails, you can put the whole partition table, plus original MLO, and uboot.image back on the sdcard like so. $ sudo dd if=/home/william/mbr-sdb.bak of=/dev/sdb bs=1M count=1 *OR* It would probably be safer / easier to just dd the whole block device into an image file stored in a safe place. On Thu, Oct 8, 2015 at 1:57 PM, Robert Nelson <[email protected]> wrote: > On Thu, Oct 8, 2015 at 3:37 PM, Christopher Stack <[email protected]> > wrote: > > Sorry that this is probably a dumb question, but is it possible to not > blow > > away the partition table since I just want to swap the MLO and > u-boot.img? > > Using dd, just re-write them to the microSD... The partition table is > safe at another location.. > > > > > I'm just running the standard image on a Beagle Bone Black that does not > > have an eMMC or hdmi chip. I assumed it was busy because I was trying to > > reprogram the disk while on an OS that was using the disk? > > > > This was the error: > > > > > > > > Checking that no-one is using this disk right now ... > > BLKRRPART: Device or resource busy > > > > > > > > > > > > > > After adding the force option it said: > > > > > > > > > > Checking that no-one is using this disk right now ... > > BLKRRPART: Device or resource busy > > > > This disk is currently in use - repartitioning is probably a bad idea. > > Umount all file systems, and swapoff all swap partitions on this disk. > > Use the --no-reread flag to suppress this check. > > > > Disk /dev/mmcblk0: 121008 cylinders, 4 heads, 16 sectors/track > > > > sfdisk: ERROR: sector 3069576189 does not have an msdos signature > > /dev/mmcblk0: unrecognized partition table type > > Old situation: > > No partitions found > > New situation: > > Units = mebibytes of 1048576 bytes, blocks of 1024 bytes, counting from 0 > > > > Device Boot Start End MiB #blocks Id System > > /dev/mmcblk0p1 * 1 3780 3780 3870720 83 Linux > > /dev/mmcblk0p2 0 - 0 0 0 Empty > > /dev/mmcblk0p3 0 - 0 0 0 Empty > > /dev/mmcblk0p4 0 - 0 0 0 Empty > > Successfully wrote the new partition table > > ah, sfdisk is just noisly, it worked ^^^^... > > > Re-reading the partition table ... > > BLKRRPART: Device or resource busy > > later versions don't show this extra stuff... > > > > > > > > > > > > > I have the serial output after the last test, but not from the test > where I > > did not recreate the partition table. > > > > > > > > > > U-Boot 2015.10-rc2-00001-g5879130-dirty (Oct 09 2015 - 15:52:49 +0000) > > > > Watchdog enabled > > I2C: ready > > DRAM: 512 MiB > > Reset Source: Global external warm reset has occurred. > > Reset Source: Power-on reset has occurred. > > MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1 > > Using default environment > > > > Net: <ethaddr> not set. Validating first E-fuse MAC > > cpsw > > Hit any key to stop autoboot: 0 > > gpio: pin 53 (gpio 53) value is 1 > > switch to partitions #0, OK > > mmc0 is current device > > gpio: pin 54 (gpio 54) value is 1 > > Checking for: /uEnv.txt ... > > Checking for: /boot.scr ... > > Checking for: /boot/boot.scr ... > > Checking for: /boot/uEnv.txt ... > > ** Invalid partition 2 ** > > ** Invalid partition 3 ** > > ** Invalid partition 4 ** > > ** Invalid partition 5 ** > > ** Invalid partition 6 ** > > ** Invalid partition 7 ** > > This looks fine, based on where you stopped... it was searching for > the microSD card... > > Regards, > > -- > Robert Nelson > https://rcn-ee.com/ > > -- > 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. > -- 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.
