Difference between revisions of "Applying Patches"

Revision as of 09:29, 9 August 2009

Introduction

We cannot legally redistribute Palm source code (it is copyrighted code, and is not released under an open source license) therefore we need to manage our modifications as patches. Since these patches will come from many different places, and will need to be removed before each OTA update and then reapplied after-wards, we need a procedure and tools for doing this. This page documents this procedure.

Upgrading from quilt to quilt-lite

If you have performed these instructions before the 8th Aug 2009, you will have installed a very heavyweight version of the quilt package which has a dependency on a very large perl package.

This dependency has been removed in a new quilt-lite package, which saves 25MB of space in /var as a result.

You can switch over to it as follows:

ipkg-opt update
ipkg-opt remove quilt perl libdb gdbm
ipkg-opt install quilt-lite

Alternatively, the setup script below will prompt to uninstall quilt, perl, libdb and gdbm, and install quilt-lite, if quilt is installed.

Setup Procedure (Scripted)

The process of setting up quilt has been scripted. The script performs the following actions:

Installs (or upgrades) git and any dependencies
Installs (or upgrades) quilt (actually quilt-lite, a version of quilt that does not depend on perl) and any dependencies
Configures quilt to store patches in /opt/src/patches
Creates (or updates) a local clone of the webos-internals modifications repository

Each step is only performed if necessary. Please note that ipkg-opt needs to be installed. The instructions are found here.

To get run the script, log into your Pre, gain root privileges and run the following commands:

 cd /tmp
 wget http://gitorious.org/webos-internals/bootstrap/blobs/raw/master/quilt-bootstrap.sh
 sh quilt-bootstrap.sh

Setup Procedure (Manual Process)

(Note: Even though you may have previously installed the optware quilt patch manager, it won't damage anything to follow the Setup procedure. Alternatively, if you KNOW FOR SURE these are installed and your packages are up-to-date, you can skip to Importing and Applying Patches).

Log into your Pre, and gain root privileges. (Note: This command is not required when using the emulator)

sudo -i # Yes, the -i is important.

Put your Pre in to Read Write Mode

mount -o remount,rw /

Ensure that you are set up for optware package installations, and make sure you have the latest package index:

ipkg-opt update

Install the 'quilt-lite' package, which will be used to manage the patches you apply, and the 'git' package, which will be used to download existing patches from the modifications repository:

ipkg-opt install quilt-lite git

(If you already have those packages installed, repeating this step will not cause any harm.)

Create a directory in which 'quilt' will manage your chosen modifications:

mkdir -p /opt/src/patches

Edit /opt/etc/quilt.quiltrc to point quilt to that directory:

sed -ire 's|^[\s#]*QUILT_PATCHES=.*|QUILT_PATCHES=/opt/src/patches|' /opt/etc/quilt.quiltrc

Clone the webos-internals modifications repository:

cd /opt/src
git clone git://gitorious.org/webos-internals/modifications.git

Importing and Applying Patches

Ensure your list of modifications is up to date

cd /opt/src/modifications
git pull

- If you find yourself getting errors when you try to pull with the above command then you will need to modify your .git/config file

sudo vi /opt/src/modifications/.git/config

- Your [master] section should look like the following

[branch "master"]
        remote = origin
        merge = refs/heads/master

Browse the set of available patches. Each patch should have a description at the top.

find /opt/src/modifications -name *.patch

Choose a patch from the modifications repository and import it into your own patches directory:

cd / # It is *very* important to be in the / directory when you run quilt.
quilt import /opt/src/modifications/application_name/patch_name.patch   # Note that you need to replace application_name and patch_name here.

Verify that quilt has imported the patch successfully:

# You should still be in the / directory to run quilt.
quilt series  # you should see your patch listed in here

Instruct quilt to apply your patch

# You should still be in the / directory to run quilt.
quilt push
# Use this to push all patches at once.
quilt push -a

If everything worked correctly, the patch should now be applied. You will usually need to restart the luna service on the Pre to see the effect of patches to applications. Here's how to initiate a rescan.

luna-send -n 1 palm://com.palm.applicationManager/rescan {}

If that doesn't work, try a service restart with:

stop LunaSysMgr && start LunaSysMgr

And if all else fails, simply reboot:

reboot

Removing all patches

Before you accept an OTA update, you should remove any patches you have applied. Luckily, using quilt makes this very easy.

Remove all patches:

cd / # It is *very* important to be in the / directory when you run quilt.
quilt pop -a

Reapplying all patches

After your OTA update is complete, you will want to reapply any patches you have selected. This may or may not go smoothly.

Apply all patches:

cd / # It is *very* important to be in the / directory when you run quilt.
quilt push -a

Put your Pre back in to Read Only mode

mount -o remount,ro /

Information for developing patches

Getting Authenticated with gitorious.org

Before you can commit to gitorious you need to create an account.

Next you'll need to generate a public key and share that with gitorious.org, your public key is how gitorious.org authenticates you and checks if have the permissions required to do a commit to a given repository.

Getting your key on window

Download PuTTYgen and Pageant

--Gitorious.org gitorious.org recommends you use msysGit.--

On Windows use PuTTYgen to generate a public/private key pair.

Key -> SSH-2 RSA KEY
Key -> Generate key pair

After some wiggling of the mouse your keys will be generated. You should fill in the //Key passphrase// and it's confirmation to secure you key. Save off the public and private key pairs to your user folder.

After which you will need to run Pageant on your pc. Pageant holds your private key in memory for PuTTY to use.

To commit changes to gitorious.org from the pre you will need to install openssh on the device.

ipkg-opt update
ipkg-opt install openssh # since dropbear doesn't do agent forwarding, you need to use openssh

Actually, it is possible to use dropbear with git but requires some hackery.

As an alternative, if you don't use the keys for anything else you could just generate them on the pre after installing open-ssh

sudo ssh-keygen -t rsa # follow the prompts
cat ~/.ssh/id_rsa.pub  # display the public key you need to paste into gitorious

Don't forget to upload your public key to gitorious.org after generating it.

Now you should be able to follow the steps below and contribute your code to gitorious.org.

If you find yourself getting errors about your public key when you try to push changes, check to make sure your keys are under /var/home/root/.ssh/ and not under your regular user account.

Creating a patch

Before making any changes to files:

cd / # It is *very* important to be in the / directory when you run quilt.
quilt new patch_name.patch
quilt add /usr/palm/applications/com.palm.app.appYouWantToMod/app/controllers/mod-assistant.js
quilt add /usr/palm/applications/com.palm.app.appYouWantToMod/app/controllers/mod2-assistant.js

Now you can make changes on the Pre using vi/nano/joe/whatever, or sftp files to your machine and make changes. Make sure any file you change has been added in the above step.

quilt files # view files that are being tracked
quilt header -e  # add a header to the patch to describe it (please do this!)

Once you are finished and ready to create a patch

quilt refresh # this will create/update the /opt/src/patches/patch_name.patch file

Pushing the change back to gitorious.org

copy the patch into the modification tree you cloned above

mkdir /opt/src/modifications/application_name # You need to change application_name to the leaf of the palm application id.
cp /opt/src/patches/patch_name.patch /opt/src/modifications/application_name/patch_name.patch

Identify yourself in git (use the user you have setup at gitorious.org)

cd /opt/src/modifications
git config --global user.name "user"
git config --global user.email "youremail@example.com"

Commit your changes to your local git

git add application_name/patch_name.patch
git commit

Since we did a clone the first time, we need to recreate the origin:

git remote rm origin # (if you did a clone, we have to replace the origin)
git remote add origin git@gitorious.org:webos-internals/modifications.git

Finally, push your changes up to gitorious.org

git push origin master # first time
git push # any future pushes

If the push does not work, try to debug the ssh connection

/opt/bin/ssh -v git@gitorious.org

Extended, annotated sample session with quilt

First, we just need to setup a file to muck with

root@castle:/# cd /
root@castle:/# echo "Original file" > /usr/test
root@castle:/# echo "2nd lien" >> /usr/test
root@castle:/# echo "3rd ilne" >> /usr/test
root@castle:/# echo "last line" >> /usr/test

Start a new patch (normally you'll want to use patch_name.patch, I just wanted a shortened name)

root@castle:/# quilt new p1
Patch /opt/src/patches/p1 is now on top

You must quilt add any files that you are going to edit or create before you edit or create them.

root@castle:/# quilt add /usr/test
File /usr/test added to patch /opt/src/patches/p1

Just using sed to correct the spelling on the 2nd line

root@castle:/# sed -i -e 's/lien/line/' /usr/test

quilt refresh actually finds what you have changed and writes it to the patch file (at this point, you can use git to push your changes)

root@castle:/# quilt refresh
Refreshed patch /opt/src/patches/p1

Just for fun, let's do it again

root@castle:/# quilt new p2
Patch /opt/src/patches/p2 is now on top

Again, add file, make some changes, refresh to update the patch.

root@castle:/# quilt add /usr/test
File /usr/test added to patch /opt/src/patches/p2
root@castle:/# sed -i -e 's/ilne/line/' /usr/test
root@castle:/# quilt refresh
Refreshed patch /opt/src/patches/p2

Just an example of rolling back changes

root@castle:/# quilt pop
Removing patch /opt/src/patches/p2
Restoring usr/test

Now at patch /opt/src/patches/p1
root@castle:/# quilt pop
Removing patch /opt/src/patches/p1
Restoring usr/test

Now at patch /opt/src/patches/enable-browser-downloads.patch
root@castle:/# cat /usr/test
Original file
2nd lien
3rd ilne
last line

delete will delete the patch from your series, but leave the actual patch file in /opt/src/patches (so you could import it later)

root@castle:/# quilt delete p1
Removed patch /opt/src/patches/p1

Since we removed p1, push will now apply p2. However, since p2 was applied against p1 originally, p2 will report an error. If the changes are too significant, you can force with -f, but you should carefully inspect the resulting files.

root@castle:/# quilt push
Applying patch /opt/src/patches/p2
patching file usr/test
Hunk #1 succeeded at 1 with fuzz 2.

Now at patch /opt/src/patches/p2

If we want, we can refresh the patch so that future users of the patch do not receive the "fuzz" warning.

root@castle:/# quilt refresh
Refreshed patch /opt/src/patches/p2
root@castle:/# cat /usr/test
Original file
2nd lien
3rd line
last line

cleanup

root@castle:/# rm /usr/test

Background info

quilt

Script for Updating/Installing Patches

I just wanted to share the following script that I just finished testing out. It's only been tested on my Pre so far, as I don't have access to any others.. It just updates the patch list, prints out available patches, then lets you choose which to apply.

#!/opt/bin/bash

cd /opt/src/modifications
tput clear
echo Updating list...
git pull
tput clear
cd /

a=0
for inputline in $(find /opt/src/modifications -name *.patch | sort)
do
 a=$(($a+1));
 line="$(echo $inputline)"
 MYARRAY[$a]="$line"
 echo "${a}${line}" | awk -F "/" 'sub(".patch","",$6) {printf "%-3s %-15s %s\n", $1, $5, $6}'
done
echo "q   quit"

x=$(($a+1));
until [ -n "$opt" ] ; do
 read -p "Enter the line number for patch to apply [1 - $a] " opt
 if [ "$opt" = "q" ] ; then
  exit 0
 fi
 if [ "$opt" -lt "$x" 2> /dev/null ] && [ "$opt" -gt 0 2> /dev/null ] ; then
  true
 else
  opt=""
 fi
done

tput clear
cd /
quilt import ${MYARRAY[$opt]}
quilt push
luna-send -n 1 palm://com.palm.applicationManager/rescan {}