From Fedora Project Wiki



OMAP5 uEVM notes

Fedora 20 uENV.txt:

setenv bootm_size 0x20000000
setenv bootargs console=${console} vram=${vram} root=LABEL=_/ ro rootwait rhgb
ext4load mmc 0:3 0x82000000 /boot/vmlinuz-3.14.0-0.rc6.git4.1.fc21.armv7hl
ext4load mmc 0:3 0x88080000 /boot/uInitrd-3.14.0-0.rc6.git4.1.fc21.armv7hl
ext4load mmc 0:3 0x88000000 /boot/dtb-3.14.0-0.rc6.git4.1.fc21.armv7hl/omap5-uevm.dtb
bootz 0x82000000 0x88080000 0x88000000



Fedora 21/rawhide notes

Install MLO and u-boot on non-vfat image: WARNING: BETA NOTES


sudo dd if=MLO           \
        of=/dev/sdz      \
      conv=fsync,notrunc \
      seek=128k

sudo dd if=u-boot.img    \
        of=/dev/sdz      \
     count=2             \
      seek=1             \
      conv=notrunc,fsync \
        bs=384k


F20 notes

  • download the f20 minimal image
wget http://download.fedoraproject.org/pub/fedora/linux/releases/20/Images/armhfp/Fedora-Minimal-VFAT-armhfp-20-1-sda.raw.xz
  • Decompress
unxz -v Fedora-Minimal-VFAT-armhfp-20-1-sda.raw.xz


  • Map the partitions
kpartx -avp _fedora_  Fedora-Minimal-VFAT-armhfp-20-1-sda.raw


  • Extract the rootfs
dd if=/dev/mapper/loop0_fedora_3 \
   of=f20-minimal-rootfs.ext4    \
 conv=fsync


  • Unmap the partitions
kpartx -dvp _fedora_  Fedora-Minimal-VFAT-armhfp-20-1-sda.raw


  • Optionally discard the official Fedora minimal image, we now have the essential rootfs.


  • Shrink the rootfs image file
e2fsck    -f  f20-minimal-rootfs.ext4 &> /dev/null
resize2fs -M  f20-minimal-rootfs.ext4


  • Create a new f20 disk image file
truncate -s 4G f20-minimal.disk


  • Partition the newly created disk image
parted -a    optimal 
       -s -- f20-minimal.disk      \
             unit MiB              \
             mklabel msdos         \
             mkpart primary 4 24   \
             mkpart primary 24 152 \
             mkpart primary 152 -1 \
             print


  • Map the partitions to loop devices
kpartx -avp _remix_ f20-minimal.disk


  • Format the partitions accordingly to the output of the previous kpartx cmd.
mkfs.vfat -n uboot -F 16              /dev/mapper/loop0_remix_1

mkswap -L swap -U $(uuidgen)          /dev/mapper/loop0_remix_2

#mkfs.ext4 -L rootfs -U $(uuidgen) -m0 /dev/mapper/loop0_remix_3


  • Copy the Fedora-20 minimal rootfs to the appropriate partition
dd if=f20-minimal-rootfs.ext4   \
   of=/dev/mapper/loop0_remix_3 \
   bs=4M conv=fsync 


  • Inflate the rootfs on the partition
resize2fs -fp /dev/mapper/loop0_remix_3


  • Unmap the partition loops devs
kpartx -dvp _remix_ f20-minimal.disk







Tips & Tricks

You can monitor the DD command in an easy one liner.

dd if=/dev/sdc3 of=f20-minimal-rootfs.ext4-ORIG &   while ps -p $! ; do kill -USR1 $! ; sleep 5 ; done


Use fsync with DD to avoid potentially dangerous filesystem buffer cache issues. My computers have large amounts of memory, and it is possible an entire file would be buffered into filesystem cache. The effect is the DD write operation appearing to finish very fast, but the filesystem empty the buffer/cache in the background asynchronously. This is like typing "sync" after the DD command, but instead happens during writes.


dd if=/dev/foo
   of=/dev/bar
 conv=[fsync|fdatasync]

This signals the DD process to spew progress info every five seconds. Especially useful on very slow sdcard, or large data transfers.