Jon Masters has provided a Pandaboard Fedora 13 image which mostly works great (the
MLO appears to not work on the new ES model, but you can strip the MLO from the Pandaboard validation image and use it instead).
However, if you have the desire to stay current, you might want to try a little newer version of Fedora. I expect the floodgates to open shortly as the Fedora ARM team is working on bootstrapping Fedora 15, but in the meantime,
Peter Robinson has provided a Fedora 14 ARM image. No, it's not specific to the Pandaboard, but we can get it working anyway with a little elbow grease. And if we leverage the work of others, we won't even have to do any compiling!
Partitioning & formatting your SD card
This is perhaps the most critical step - and
one with many nuances and folklore. The image provided by Peter is "generic" in the fact that it doesn't have Pandaboard specific files or image layout. What this means is that we'll have to provide an additional partition: the MLO/uboot partition for Pandaboard.
There have been some reported problems with specific SD cards, so I would suggest using a high quality SD card (I have used both
Micro Center "generic" card and a
PNY professional card without issues). If there is any doubt about the card,
try the validation image first.
Once you have the card in hand, you can insert it into your computer and examine /var/log/messages to determine which device is assigned by the kernel. In my case, this is what was reported:
sd 4:0:0:2: [sde] 15644672 512-byte logical blocks: (8.01 GB/7.45 GiB)
Also, it's worth noting that if there are mountable filesystems, they are probably mounted. That's not what we want, so be sure to unmount any mounted filesystems from this card.
Now I use fdisk to create two partitions:
- The uboot/MLO partition sized at about 64 MB.
- The rest of the card for the system.
There is two things worth mentioning here. Most people also create a separate swap, boot, and root partitions. I'm not going to do that here. I'm going to instead create a 2nd partitions to use as a PV (Physical Volume) for LVM. I will then later create Logical Volumes for swap and root filesystems. I will not be creating a separate /boot filesystem. The reason that this is many times distinct from the root filesystem is because it makes recovery easier if you can mount up root and make changes. Since the /uboot partition/filesystem will be copies of files from /boot, I won't make it separate - the /uboot filesystem will contain the important files.
Now create the two partitions:
# fdisk /dev/sde
Command (m for help): c
DOS Compatibility flag is set (DEPRECATED!)
Command (m for help): o
Building a new DOS disklabel with disk identifier 0xaa802e39.
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 (with command 'c').
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (62-15644671, default 62): 63
Last sector, +sectors or +size{K,M,G} (63-15644671, default 15644671): +64M
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 6
Changed system type of partition 1 to 6 (FAT16)
Command (m for help): a
Partition number (1-4): 1
Command (m for help): p
Disk /dev/sde: 8010 MB, 8010072064 bytes
247 heads, 62 sectors/track, 1021 cylinders, total 15644672 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xaa802e39
Device Boot Start End Blocks Id System
/dev/sde1 * 63 131135 65536+ 6 FAT16
Partition 1 does not end on cylinder boundary.
Command (m for help): n
Partition type:
p primary (1 primary, 0 extended, 3 free)
e extended
Select (default p): p
Partition number (1-4, default 2): 2
First sector (62-15644671, default 62): 131136
Last sector, +sectors or +size{K,M,G} (131136-15644671, default 15644671):
Using default value 15644671
Command (m for help): t
Partition number (1-4): 2
Hex code (type L to list codes): 8e
Changed system type of partition 2 to 8e (Linux LVM)
Command (m for help): p
Disk /dev/sde: 8010 MB, 8010072064 bytes
247 heads, 62 sectors/track, 1021 cylinders, total 15644672 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xaa802e39
Device Boot Start End Blocks Id System
/dev/sde1 * 63 131135 65536+ 6 FAT16
Partition 1 does not end on cylinder boundary.
/dev/sde2 131136 15644671 7756768 8e Linux LVM
Partition 2 does not end on cylinder boundary.
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: If you have created or modified any DOS 6.x
partitions, please see the fdisk manual page for additional
information.
Syncing disks.
#
You'll notice that I forced the 1st partition to start at sector 63 even though this was listed as no longer a requirement. For whatever reason, I was unable to get a starting sector of 2048 (the default when not using DOS-compatability mode) to work. Your mileage may vary.
We'll want to format that first partition too:
# mkfs -t vfat -F 16 -n uboot /dev/sde1
mkfs.vfat 3.0.12 (29 Oct 2011)
#
Installing the boot files
Now to save some time creating the boot partition, we're going to borrow MLO and uboot binaries from the
Pandaboard validation image and a previous Fedora-13 Pandaboard image. Download this image and copy the binaries to your local directory. Now let's discover how the image is laid out:
# fdisk -l validation-19102011.img
Disk validation-19102011.img: 83 MB, 83886080 bytes
255 heads, 63 sectors/track, 10 cylinders, total 163840 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
validation-19102011.img1 * 63 80324 40131 c W95 FAT32 (LBA)
validation-19102011.img2 80325 144584 32130 83 Linux
#
From this, we can know that the uboot filesystem is located at 512 bytes per sector x 63 sectors = 32256 bytes. Let's mount it and copy out the files we need. All we really need is MLO and u-boot.bin, but we'll go ahead and grab the uImage for some quick testing too.
# mkdir tmp
# losetup --offset 32256 --show --find ./validation-19102011.img
/dev/loop0
# mount /dev/loop0 ./tmp
# ls tmp
MLO u-boot.bin uImage
# cp tmp/MLO tmp/u-boot.bin tmp/uImage .
# umount ./tmp
# losetup -d /dev/loop0
# rmdir tmp
#
Now, let's copy the MLO, u-boot.bin, and uImage files to the flash. The MLO must be the first file written, and never be re-written, so we have to take special precautions to make sure that this happens correctly with no other writes.
# mount /dev/sde1 /mnt/tmp
# cp MLO /mnt/tmp/
# sync
# umount /mnt/tmp
# mount /dev/sde1 /mnt/tmp
# cp u-boot.bin uImage /mnt/tmp/
# umount /mnt/tmp
So this should be enough to at least test and make sure we laid it out right. Let's eject the media and try booting it on the Pandaboard.
# eject /dev/sde
#
A quick test
Welcome to minicom 2.5
OPTIONS: I18n
Compiled on Apr 6 2011, 07:59:07.
Port /dev/ttyUSB0
Press CTRL-A Z for help on special keys
Texas Instruments X-Loader 1.41 (Sep 29 2011 - 10:43:53)
OMAP4460: 1.2 GHz capable SOM
Starting OS Bootloader from MMC/SD1 ...
U-Boot 1.1.4-gc1cd80bc-dirty (Oct 12 2011 - 17:56:27)
Load address: 0x80e80000
DRAM: 1024 MB
Flash: 0 kB
Using default environment
In: serial
Out: serial
Err: serial
Hit any key to stop autoboot: 0
mmc read: Invalid size
4020344 bytes read
## Booting image at 82000000 ...
Image Name: Linux-3.0.4+
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 4020280 Bytes = 3.8 MB
Load Address: 80008000
Entry Point: 80008000
Verifying Checksum ... OK
OK
Starting kernel ...
Uncompressing Linux... done, booting the kernel.
[ 0.000000] Linux version 3.0.4+ (danders@ccd-dev) (gcc version 4.3.3 (Sourc1
[ 0.000000] CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c5387f
...
[ 8.663208] Waiting 3sec before mounting root device...
[ 12.223846] b301 65536 mmcblk0p1 00000000-0000-0000-0000-00000001
[ 12.233856] b302 7756768 mmcblk0p2 00000000-0000-0000-0000-00000002
[ 12.242279] No filesystem could mount root, tried: ext3
[ 12.242279] Kernel panic - not syncing: VFS: Unable to mount root fs on unkn)
...
If you saw your board get at least to the point of trying to mount the root and failing, this is a good sign. This means that the MLO, u-boot.bin, and uImage files are all functional.
Next step is to get it booting a Fedora image - that's the next post.
