To upload your image to Amazon EC2, you need to ensure that your image is in the raw format. You can do that by create the image in the raw format to start with, or you can covert it at a later time. For example, to convert a Virtual Box Image to a raw format, you can run the following command.

VBoxManage internalcommands converttoraw ec2.vdi ec2.img

We compress the image to avoid uploading a bunch of zero-ed disk.

gzip -9 ec2.img

My image is 8 GB uncompressed and 334 MB compressed.

We create a standard Amazon instance, upload the image. We then attach an EBS volume the appropriate size for our image. We then extract the new image onto the EBS volume.

gzip -c -d ec2.img.gz | dd of=/dev/xvdf bs=10M

Detach the image and create a snapshot.

We then register our image with a user provider kernel. See Custom Kernel Docs.

Here is an example command for North Virginia

ec2-register -a x86_64 -n "CentOS 6.5" -d "CentOS 6.5 x86_64 minimal install \
Provided by me" --root-device-name /dev/sda -b /dev/sda="snap-b9db2b10":8:true -b /dev/sdf=ephemeral0 --kernel aki-b4aa75dd -K somekey.pem -C somecert.pem

Or using the newer ami command

aws ec2 register-image --architecture x86_64 --name "CentOS 6.5" --description "CentOS 6.5 x86_64 minimal install \
Provided by me" --root-device-name /dev/sda --block-device-mappings "[{\"DeviceName\": \"/dev/sda\", \"Ebs\": {\"SnapshotId\": \"snap-b9db2b10\", \"VolumeSize\":8}},{\"DeviceName\": \"/dev/sdf\",\"VirtualName\":\"ephemeral0\"}]" --kernel-id aki-b4aa75dd