SDK/Docs/1.0/Building a MeeGo chroot on Linux

Revision as of 11:09, 18 October 2010

This document describes how to create a MeeGo chroot environment from a stock image.

Note that the approach covered here uses an x86 CPU to build software for an x86 version of MeeGo (e.g. a netbook image).

If you want a really quick method for developing on MeeGo where you don't need to build the chroot, see Hello World - MeeGo x86 development on Linux.

Pre-requisites

All that's required for this is a reasonably modern Linux distribution (e.g. Fedora 11, Ubuntu 9.10).

Download and unpack a MeeGo image

Get an image or tarball (with a UX) from http://repo.meego.com/MeeGo/releases/; either a netbook or handset image.

The process for unpacking is slightly different, depending on the type of image.

Unpacking a netbook image

1. Install MeeGo Image Creator (MIC): use the instructions at http://wiki.meego.com/Image_Creation#Installation
2. Unpack the image using MIC:
   

   sudo mic-chroot --unpack-only -s /path/to/meego-chroot <image file>.usbimg

Replace /path/to/meego-chroot with your desired path.

Unpacking a handset image

1. Install kpartx (a tool for creating device maps from partition tables: because the handset images are raw disk images, this tool can be used to create a device map from the disk image, which can then be mounted on the filesystem)
   

   yum install kpartx

   or on non-RPM distros:

   apt-get install kpartx

2. Unpack the tarball:
   

   tar jxvf meego-0.90-preview-shcdk-20100512-001.tar.bz2

   This leaves you with a directory which contains the raw disk image you're interested in.

3. Create a device map from the raw image:
   

   cd meego-0.90-preview-shcdk-20100512-001
   sudo kpartx -a -v ./meego-0.90-preview-shcdk-20100512-001-sda.bin
   

   Note that this maps the first partition (p1) of the disk image onto the loop device /dev/loop0.

4. Mount the device map and copy the filesystem into the chroot location:
   

   mkdir ~/tmp-mnt   # temporary mount point
   sudo mount /dev/mapper/loop0p1 ~/tmp-mnt -o loop,ro
   mkdir ~/meego-chroot
   sudo rsync -av ~/tmp-mnt ~/meego-chroot
   sudo umount ~/tmp-mnt
   

5. Remove the device map:
   

   sudo kpartx -d -v ./meego-0.90-preview-shcdk-20100512-001-sda.bin
   

6. Remove the temporary mount point:
   

   rmdir ~/tmp-mnt
   

Using the chroot

Chroot into the image using mic-chroot.

To use the script with the unpacked chroot:

sudo mic-chroot /path/to/meego-chroot