Cyclone Boot From USB

From richud.com
Jump to: navigation, search

Boot Cyclone from USB stick

  • You can do this directly to your USB stick, however it may be easier to create an image which can then be written out to any stick, quickly.
  • Creating an image also means you can test very quickly with qemu.

For more detailed information about this process please see [] []

Create empty 8Mb image

$ dd if=/dev/zero of=/tmp/test.ima bs=512 count=16384
16384+0 records in
16384+0 records out
8388608 bytes (8.4 MB) copied, 0.0160887 s, 521 MB/s

Put MBR on it

$ dd if=syslinux-4.05/mbr/mbr.bin of=/tmp/test.ima bs=440 count=1 conv=notrunc
1+0 records in
1+0 records out
440 bytes (440 B) copied, 1.7179e-05 s, 25.6 MB/s

Partition image

Dont forget to set it active! Accept defaults for start/end.

$ fdisk /tmp/test.ima
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xf3e250f0.
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)

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4, default 1): 1
First sector (2048-16383, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-16383, default 16383): 
Using default value 16383

Command (m for help): a
Partition number (1-4): 1

Command (m for help): p

Disk /tmp/test.ima: 8 MB, 8388608 bytes
255 heads, 63 sectors/track, 1 cylinders, total 16384 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: 0xf3e250f0

        Device Boot      Start         End      Blocks   Id  System
/tmp/test.ima1   *        2048       16383        7168   83  Linux

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

Syncing disks.

Mount partitioned image on loop device

This is using offset to start of the partition (the start of the filesystem), see http://www.richud.com/wiki/Ubuntu_Create_Hard_Drive_Image#Get image offset to mount on loop device

$ losetup -o 1048576 /dev/loop0 /tmp/test.ima

Format ext4

Not using FAT saves having to fixup the boot sector

$ mkfs.ext4 -L Cyclone /dev/loop0
mke2fs 1.41.14 (22-Dec-2010)
Filesystem label=Cyclone
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
1792 inodes, 7168 blocks
358 blocks (4.99%) reserved for the super user
First data block=1
Maximum filesystem blocks=7340032
1 block group
8192 blocks per group, 8192 fragments per group
1792 inodes per group

Writing inode tables: done                            
Creating journal (1024 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 36 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

Remove wasted space

(Can omit the tune steps if feeling lazy)

$ tune2fs /dev/loop0 -m0 -O sparse_super
tune2fs 1.41.14 (22-Dec-2010)
Setting reserved blocks percentage to 0% (0 blocks)
$ tune2fs -O ^has_journal /dev/loop0
tune2fs 1.41.14 (22-Dec-2010)

Mount created image

$ udisks --mount /dev/loop0
Mounted /org/freedesktop/UDisks/devices/loop1 at /media/Cyclone

Create extlinux boot sector

  • This is equivalent command to writing a syslinux boot sector for FAT
$ syslinux-4.05/extlinux/extlinux --install /media/Cyclone
/media/Cyclone is device /dev/loop0
Warning: unable to obtain device geometry (defaulting to 64 heads, 32 sectors)
         (on hard disks, this is usually harmless.)

Create kernel image from Rom-o-Matic

  • select syslinux/grub/lilo kernel
  • select all drivers (default)
  • Enter this into the script box, changing XXX for you ip/hostname and "pxe" to your server pxe root path, if changed
dhcp net0
set 209:string pxelinux.cfg/default
set 210:string http://xxx.xxx.xxx.xxx/pxe/
chain ${210:string}pxelinux.0
  • click create image , save out created kernel "gpxe-1.0.1+-gpxe.lkrn", in this examples to /media/7200.12/gpxe-1.0.1+-gpxe.lkrn


Copy kernel to mounted stick

$ cp /media/7200.12/gpxe-1.0.1+-gpxe.lkrn /media/Cyclone/

Create the most basic config

$ echo "DEFAULT /gpxe-1.0.1+-gpxe.lkrn" > /media/Cyclone/syslinux.cfg

Unmount image

$ udisks --unmount /dev/loop0

Test the image

(optional)

qemu -hda /tmp/test.ima

It should boot up and connect to your server

Copy image to usb stick

Insert a USB stick and make sure its unmounted (automount may well be default), assuming its /dev/sdd

$ udisks --unmount /dev/sdd1

Then write the image to the stick, and "sync" to make sure its finished writing.

$ dd if=/tmp/test.ima of=/dev/sdd bs=1M
8+0 records in
8+0 records out
8388608 bytes (8.4 MB) copied, 6.38277 s, 1.3 MB/s
$ sync

Then you can yank the stick out and it should chain load through to the server! You can now image from anywhere you have inet connection!