- 1 Summary
- 2 Important
- 3 Cloning the kernel
- 4 Submitting patches to kernel-x86-ivi
- 5 Kernel configuration
- 6 Debugging boot issues
- 7 Useful tips
The kernel-x86-ivi kernel is the kernel for Tizen IVI profile.
- Maintainer: email@example.com
- Mailing list: firstname.lastname@example.org (Subscribe here)
The original author of wiki this page is Artem Bityutskiy <email@example.com>.
Important things to know when working with the Tizen IVI kernel.
- We accept only patches from upstream (see this section for details).
- Always Cc the Tizen IVI mailing list when you want to discuss kernel-related matters with the maintainer. I prefer to have publically-visible conversations unless there is a good reason to keep them private.
- Don't modify the packaging changelog file (
packaging/kernel-x86-ivi.changes) please, I'll do this myself when I release the kernel.
Cloning the kernel
To clone the tree only, use:
git clone git://review.tizen.org/profile/ivi/kernel-x86-ivi.git # The latest Tizen stuff is in branch "tizen" git checkout -b tizen origin/tizen
I am behind the proxy, and in the global "
.$HOME/.gitconfig" git configuration file I have the following:
# Please, substitute "USER" with your tizen.org user name. # Please, substitute internal.com with your internal domain name where # you have direct access. Or just remove that line if it is irrelevant # for you. [core] gitproxy = none for internal.com gitproxy = /home/USER/bin/git-proxy-command.sh
And here is my "
#!/bin/sh # Please, substitute "proxy.qu-qu.gov" with your proxy URL. proxy="proxy.qu-qu.gov" socat STDIO SOCKS4:$proxy:$1:$2
If you have a clone of the upstream kernel tree, it may be a good idea (but optional)
to reference it while cloning using the "
--reference" option. This
option makes git share common object between the local clone of the upstream
tree and kernel-x86-ivi. That will save disk space and make
cloning much faster.
The gitweb view of the kernel tree is here: https://review.tizen.org/git/?p=profile/ivi/kernel-x86-ivi.git;a=summary
Cloning for later contributions
Getting gerrit access
Create a tizen.org account and request gerrit access before contributing to the kernel via tizen.org gerrit. Open www.tizen.org, click "Register" and follow the instructions to create an account.
To request gerrit access rights: Login to www.tizen.org, click "My account", then open the "Access Requests" tab, and request gerrit access.
Upload SSH keys
Once the tizen.org gerrit server has your public SSH key, you are ready to clone the Tizen IVI kernel.
# Please, substitute "USER" with your tizen.org user name. git clone ssh://firstname.lastname@example.org:29418/profile/ivi/kernel-x86-ivi
Find more information here.
I have to pass through the SOCKS proxy, and here is my configuration, just for reference.
In the "
$HOME/.ssh/config" file I have the following:
# Please, substitute "USER" with your tizen.org user name. # Please, substitute "proxy.qu-qu.gov" with your proxy URL. Host review.tizen.org Port 29418 User USER ProxyCommand socat STDIO SOCKS4:proxy.qu-qu.gov:%h:%p
And with this, I can clone the IVI kernel like this:
$ git clone review.tizen.org:profile/ivi/kernel-x86-ivi
Submitting patches to kernel-x86-ivi
The upstream story
We generally accept only those kernel patches that are either in Linuses tree or in a subsystem tree (e.g., wireless-next.git, usb.git, sound.git, etc). In the latter case, the patches should be visible in linux-next.git.
Generally you should back-port patches from upstream kernel trees, with the following exceptions:
- Enable/disable features in the configuration file (
- Packaging changes (see the
packaging/sub-directory in the Tizen IVI kernel sources);
- Reverts of existing commits;
- Simple and urgent fixes.
In any case, you should demonstrate that you or someone else is working with upstream on the issue (e.g., provide an LKML URL).
Always apply common sense and do not hesitate to talk to the maintainer, with a cc the mailing list.
How to back-port properly
First rule of thumb: you must preserve the original author's name.
Do not modify the commit at all, neither the commit message
(except the upstream and JIRA references, see below), nor the patch
(except some minor amendments which you may have to do to make the patch
apply cleanly). You can append your own "
Start with something like the following for all the patches you back-port:
git format-patch -1 <commit_id>
Then add the upstream reference to all of the patches. For example, if you back-port from Linuses tree, you can do the same as Greg KH does in his linux-stable tree. For example, in this commit, which was back-ported from commit 78b495c of Linuses tree, Greg added the following note:
commit 78b495c39add820ab66ab897af9bd77a5f2e91f6 upstream
If you are back-porting from a subsystem tree, use the name of the subsystem tree instead of "upstream", as follows:
commit 182f514f883abb5f942c94e61c371c4b406352d4 in ext4.git (git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git)
Then specify which JIRA issue the patches fix below the upstream reference. For example:
commit 3064837289259843310b266a9422aca5f5b4b9c7 in bluetooth-next.git (git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git) Fixes TIVI-203.
Use the gerrit review messages or a follow-up e-mail for additional information if you are sending your patch by e-mail instead of using gerrit.
If you submit your own patch, keep in mind best practices for writing commit messages. Use a subject line that indicates which subsystem is involved and what the patch is (a fix, an optimization, a clean-up, etc). Describe all the details in the commit message. Explain the problem and how it is addressed. Also, make sure each patch does just one thing. Split your changes into a patch-set when necessary.
Where to submit patches
In Tizen gerrit is used for submitting and reviewing patches. To submit kernel-x86-ivi patches, clone it and push the patches to the "refs/for/tizen" reference.
# Clone the kernel $ git clone --reference $HOME/git/linux review.tizen.org:profile/ivi/kernel-x86-ivi $ cd kernel-x86-ivi # Now apply your patches (test them first). Then # push them out to gerrit. $ git push origin HEAD:refs/for/tizen
Once the patches are reviewed in gerrit, they will be merged. The maintainer releases the updated kernel and it reaches the Tizen IVI images later.
Do not change the packaging changelog file
packaging/kernel-x86-ivi.changes) - I will do it for
you, based on the commit messages.
If you have issues with gerrit, you may also send your patches to me: the maintainer, with a cc the mailing list.
The kernel-x86-ivi configuration is called "ivi_defconfig". This configuration is meant to be optimized for Tizen IVI reference devices. The optimization is around boot time: we are trying to make sure most of the required drivers and kernel features are compiled into the kernel (instead of being kernel modules) because this boots the system faster. Drivers that are not necessarily used when Tizen IVI boots up may be kernel modules.
The other general concept is that we are trying to exclude useless drivers and not compile them at all. This makes the kernel package smaller.
We are also trying to support non-target hardware, like commodity laptops, so we try to make sure the drivers for non-target HW are enabled as kernel modules. If you find that a piece of HW you need has a corresponding kernel driver in the kernel but this driver is disabled, file a JIRA issue and assign it to the kernel maintainer.
We also try to keep track of the drivers requested in the following table.
|Various virtio and virtual machine drivers to make Tizen IVI work in virtual machines||CONFIG_DRM_VMWGFX, CONFIG_DRM_VMWGFX_FBCON, CONFIG_VIRTIO_BLK, CONFIG_VMWARE_BALLOON, CONFIG_VMWARE_PVSCSI, CONFIG_SCSI_VIRTIO, CONFIG_VIRTIO_NET, CONFIG_VIRTIO_CONSOLE, CONFIG_HW_RANDOM_VIRTIO, CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_BALLOON, CONFIG_VIRTIO_MMIO, CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES, CONFIG_SND_ENS1371
Note: CONFIG_DRM_VMWGFX is currently configured as a built-in module (
|Support various Logitech devices, e.g., requested by Geoffroy Van Custem to support the G27 Racing wheel||CONFIG_HID_LOGITECH, CONFIG_LOGITECH_FF, CONFIG_LOGIG940_FF, CONFIG_LOGIWHEELS_FF, CONFIG_HID_LOGITECH_DJ|
|The kernel->userspace connector feature, required by Murphy, see TIVI-713||CONFIG_CONNECTOR, CONFIG_PROC_EVENTS|
|The memory controller cgroup, required by systemd, see TIVI-970||CONFIG_MEMCG|
|HDMI/DP HDA audio codec, requested by Geoffroy VanCutsem||CONFIG_SND_HDA_CODEC_HDMI|
|A contemporary USB-serial adapter driver, requested by Joonas Lahtinen||CONFIG_USB_SERIAL_FTDI_SIO|
|A contemporary USB-ethernet adapter driver, requested by Joonas Lahtinen||CONFIG_USB_NET_SMSC75XX|
|WIFI tethering with connman, see the connman/README file||CONFIG_BRIDGE, CONFIG_NETFILTER, CONFIG_NF_CONNTRACK_IPV4, CONFIG_NF_NAT_IPV4, CONFIG_IP_NF_TARGET_MASQUERADE, CONFIG_IP_MULTIPLE_TABLES, CONFIG_NETFILTER_NETLINK_ACCT, CONFIG_NETFILTER_XT_MATCH_NFACCT|
|Designware USB driver and various USB gadget drivers. The BayTrail SoC includes a DesignWare USB controller capable of supporting the gadget mode. Although we do not use this mode in Tizen IVI, some people may find it useful to have the drivers available.||CONFIG_USB_DWC3, CONFIG_USB_DWC3_GADGET, CONFIG_USB_GADGET, CONFIG_USB_ZERO, CONFIG_USB_ETH, CONFIG_USB_G_NCM, CONFIG_USB_FUNCTIONFS, CONFIG_USB_MASS_STORAGE, CONFIG_USB_G_SERIAL|
|AT keyboard and PS2 mouse drivers, required for running Tizen IVI in VMWare, see TIVI-2025||CONFIG_KEYBOARD_ATKBD, CONFIG_MOUSE_PS2|
|PCAN USB driver, needed for testing AMB, see TIVI-2263||CONFIG_CAN_PEAK_USB|
|TouchScreen support for Lenovo X230, see TIVI-2396||CONFIG_INPUT_TABLET, CONFIG_TABLET_USB_WACOM|
|SCSI adapter exposed to Virtual Machines by VMware, see TIVI-2676. This must be built-in (and not a module) since you need it to mount the rootfs||CONFIG_FUSION=y, CONFIG_FUSION_SPI=y|
|Enable specific CGROUP features, specifically "Network bandwidth management" (net_cls, net_prio) and "Storage bandwidth management" (blkio) in the kernel, see TIVI-2678. Modules were used where available.||CONFIG_BLK_CGROUP=y, CONFIG_BLK_DEV_THROTTLING=y, CONFIG_CFQ_GROUP_IOSCHED=y, CONFIG_NET_SCHED=y, CONFIG_NET_CLS_CGROUP=m, CONFIG_CGROUP_NET_PRIO=m|
|Support libvirt-lxc in kernel, see TIVI-3217||CONFIG_UTS_NS=y, CONFIG_IPC_NS=y, CONFIG_PID_NS=y, CONFIG_USER_NS=y, CONFIG_NETFILTER_XT_TARGET_CHECKSUM=m, CONFIG_BRIDGE_VLAN_FILTERING=y, CONFIG_VLAN_8021Q=m, CONFIG_VETH=m, CONFIG_DEVPTS_MULTIPLE_INSTANCES=y, CONFIG_CFS_BANDWIDTH=y|
|Support i801 SMBus device. MAX9867 audio codec is controlled over a SMBus port, so this driver enables userspace to control it by using /dev/i2c dev. See TC-59||CONFIG_I2C_I801=m|
Debugging boot issues
Unfortunately, sometimes Tizen IVI systems may not boot to the UI or console, in which case you usually see a black screen or the splash image and no useful information.
The reason for this is that we use the the "quiet" kernel option in Tizen IVI to facilitate a faster boot. This option affects both kernel and systemd startup messages. The first step to fix this is to remove the "quiet" option from the Tizen IVI kernel boot arguments.
For MBR images edit the "
For EFI images edit the "
Capturing boot logs via serial line
Usually disabling the "quiet" option is enough to resolve the problem or to understand where it is. Sometimes the problem is in one of the systemd services, not in the kernel. Enable the serial port logging if useful error messages are not shown on the display.
To enable serial port logging add the following options to the Tizen IVI kernel boot arguments:
console=tty0 console=ttyS0,115200 ignore_loglevel". This will make the Tizen IVI
kernel send all the kernel output to the serial line. The serial
console should be available on a successful boot.
Use the "minicom" program to capture the boot output on the host side (confirm you have minicom configured properly).
How to change the configuration file
Use the following example to change the kernel configuration (for example, to add support for a feature or a driver).
For example, change the
ivi_defconfig configuration, found in
arch/x86/configs" subdirectory, to enable the
"PPS" (Pulse Per Second) subsystem (
$ make ARCH=i386 ivi_defconfig # Configure the kernel $ make ARCH=i386 menuconfig # or xconfig or gconfig # Enable the PPS feature, exit the configurator $ make ARCH=i386 savedefconfig $ mv defconfig arch/x86/configs/ivi_defconfig $ git commit -a -s
In general terms, first apply the configuration you need to change
ivi_defconfig), modify it, save it ("
and possibly commit it.
How to fetch files from an RPM
# This will fetch all files from the kernel package and place them # in the current directory. $ rpm2cpio kernel-x86-ivi.i686.rpm | cpio -idmv
Git e-mail aliases
It is useful to have aliases for the most frequently used e-mail addresses.
They are helpful when dealing with "
git send-email". Add something
like the following to the "
[sendemail] aliasesfile=/home/dedekind/.mutt-aliases aliasfiletype=mutt
where the "
.mutt-aliases" file contains records like these:
alias lkml Linux Kernel <email@example.com> alias artem Artem Bityutskiy <firstname.lastname@example.org>
When using 'git send-email', specify something like "
--to lkml" instead of
How to add a project to the watchlist in tizen.org gerrit
- Confirm that you have a tizen.org account and gerrit access rights (see this section).
- Open https://review.tizen.org/gerrit and sign in
- In the upper right corner click "Settings"
- On the left-side menu select "Watched Projects"
- In the "Project name" field type "profile/ivi/kernel-x86-ivi" and press "Enter"
How use "git send-email"
When working with upstream send your patches to one of the
mailing lists. This is usually done using the "
git send-email" command.
Suppose you have a properly formatted patch-set that you created using the
git format-patch" command. You can send your patches upstream
using the following command:
$ git send-email --to email@example.com --cc firstname.lastname@example.org 0*
You should know where to send the patch to (see this section for more information).
Note: "git send-email" can sometimes send e-mails to people you did not expect. For example, it may send the e-mails to the names found in the "Signed-off-by:" tags. Configure "git send-email" to prevent this. Here is my configuration (from "$HOME/.gitconfig")
[sendemail] smtpserver = smtp.intel.com signedoffcc = false suppresscc = all chainreplyto = false assume8bitEncoding = utf-8
- always use the "--dry-run" option to check that "git send-email" will do what you want
- "git send-email" is interactive, so you do not have to specify the recipients at the command line
- never use chained "In-Reply-To:" ("--chain-reply-to" option) - it is much more difficult to work with in the mailing list
Where in upstream to send my patch to?
Identify the following if you have to upstream your patches:
- maintainers' name
- the mailing list to send the patch to
- the kernel tree to create the patch against
This information is typically found in the "MAINTAINERS" file which is a part of the Linux kernel tree. Check the file, find the subsystem you are going to change, and then send the patch to the subsystem maintainer(s) and cc the subsystem mailing list(s). The "MAINTAINERS" file also typically has the subsystem's git tree URL. Clone the subsystem git tree and make sure your patch applies against this tree. For non-trivial patches make sure it also actually works with this tree.
scripts/get_maintainer.pl" script (also part of the kernel tree) can
help you find out the names. For example, if you have a patch "hda.patch", run:
$ scripts/get_maintainer.pl --scm hda.patch
or if you change file "
sound/pci/hda/hda_intel.c" and want to know where to send the patch, run:
$ scripts/get_maintainer.pl --scm -f sound/pci/hda/hda_intel.c Jaroslav Kysela <email@example.com> (maintainer:SOUND) Takashi Iwai <firstname.lastname@example.org> (maintainer:SOUND,commit_signer:69/69=100%) Pierre-Louis Bossart <email@example.com> (commit_signer:4/69=6%) David Henningsson <firstname.lastname@example.org> (commit_signer:4/69=6%) email@example.com (moderated list:SOUND) firstname.lastname@example.org (open list) git git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git git git://git.alsa-project.org/alsa-kernel.git git git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
From the output you can see that Jaroslav Kysela is the maintainer, as well as Takashi Iwai. Pierre-Louis Bossart signed 6% of commits for this file, just like David Henningsson. The "email@example.com" is the mailing list for the sound subsystem. There is a list of related kernel trees. The top records are usually the most relevant.
scripts/get_maintainer.pl -h" for more details.
In this particular case you should probably clone the "sound.git" tree, make sure
the patch can be cleanly applied to this tree using the
git apply --check hda.patch" command, then send the patch to the
maintainers and the mailing list using the following command
(see this section for more info):
git send-email --from "Your Name <your@email>" --to "Jaroslav Kysela <firstname.lastname@example.org>" --to "Takashi Iwai <email@example.com>" --cc "firstname.lastname@example.org" --cc "email@example.com" hda.patch