[gnome-continuous-yocto/gnomeostree-3.28-rocko: 6705/8267] kernel-dev, dev-manual: Moved Yocto Linux kernel overview
- From: Emmanuele Bassi <ebassi src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gnome-continuous-yocto/gnomeostree-3.28-rocko: 6705/8267] kernel-dev, dev-manual: Moved Yocto Linux kernel overview
- Date: Sun, 17 Dec 2017 05:13:12 +0000 (UTC)
commit bdeb6db2fbc8563b03ea17d9c18a5fa19830e12f
Author: Scott Rifenbark <srifenbark gmail com>
Date: Thu Jun 29 09:32:57 2017 -0700
kernel-dev, dev-manual: Moved Yocto Linux kernel overview
Fixes [YOCTO #11630]
I took the Yocto Linux kernel overview list of kernels out of the
dev-manual and moved them to the "Yocto Project Kernel Development
and Maintenance" section in Appendix A of the kernel-dev manual.
This is a much more logical area to introduce this type of Yocto
Linux kernel information.
(From yocto-docs rev: 0a5154cb4c23697f2b8e2341c8e1dc07362443d2)
Signed-off-by: Scott Rifenbark <srifenbark gmail com>
Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>
documentation/dev-manual/dev-manual-model.xml | 69 +-------
.../kernel-dev/kernel-dev-concepts-appx.xml | 207 ++++++++++++++------
2 files changed, 150 insertions(+), 126 deletions(-)
---
diff --git a/documentation/dev-manual/dev-manual-model.xml b/documentation/dev-manual/dev-manual-model.xml
index 30428b2..bd6a85b 100644
--- a/documentation/dev-manual/dev-manual-model.xml
+++ b/documentation/dev-manual/dev-manual-model.xml
@@ -86,71 +86,6 @@
<title>Kernel Overview</title>
<para>
- Traditionally, when one thinks of a patched kernel, they think of a base kernel
- source tree and a fixed structure that contains kernel patches.
- The Yocto Project, however, employs mechanisms that, in a sense, result in a kernel source
- generator.
- By the end of this section, this analogy will become clearer.
- </para>
-
- <para>
- You can find a web interface to the Yocto Project kernel source repositories at
- <ulink url='&YOCTO_GIT_URL;'></ulink>.
- If you look at the interface, you will see to the left a grouping of
- Git repositories titled "Yocto Linux Kernel."
- Within this group, you will find several kernels supported by
- the Yocto Project:
- <itemizedlist>
- <listitem><para><emphasis>
- <filename>linux-yocto-4.1</filename></emphasis> - The
- stable Yocto Project kernel to use with the Yocto
- Project Release 2.0.
- This kernel is based on the Linux 4.1 released kernel.
- </para></listitem>
- <listitem><para><emphasis>
- <filename>linux-yocto-4.4</filename></emphasis> - The
- stable Yocto Project kernel to use with the Yocto
- Project Release 2.1.
- This kernel is based on the Linux 4.4 released kernel.
- </para></listitem>
- <listitem><para><emphasis>
- <filename>linux-yocto-4.9</filename></emphasis> - The
- stable Yocto Project kernel to use with the Yocto
- Project Release 2.3.
- This kernel is based on the Linux 4.9 released kernel.
- </para></listitem>
- <listitem><para><emphasis>
- <filename>linux-yocto-4.10</filename></emphasis> - The
- default stable Yocto Project kernel to use with the
- Yocto Project Release 2.3.
- This kernel is based on the Linux 4.10 released kernel.
- </para></listitem>
- <listitem><para><emphasis>
- <filename>linux-yocto-dev</filename></emphasis> - A
- development kernel based on the latest upstream release
- candidate available.
- </para></listitem>
- </itemizedlist>
- <note>
- Long Term Support Initiative (LTSI) for Yocto Project kernels
- is as follows:
- <itemizedlist>
- <listitem><para>For Yocto Project releases 1.7, 1.8, and 2.0,
- the LTSI kernel is <filename>linux-yocto-3.14</filename>.
- </para></listitem>
- <listitem><para>For Yocto Project releases 2.1, 2.2, and 2.3,
- the LTSI kernel is <filename>linux-yocto-4.1</filename>.
- </para></listitem>
- <listitem><para><filename>linux-yocto-4.1</filename>,
- <filename>linux-yocto-4.4</filename>, and
- <filename>linux-yocto-4.9</filename> are all LTS
- kernels.
- </para></listitem>
- </itemizedlist>
- </note>
- </para>
-
- <para>
The kernels are maintained using the Git revision control system
that structures them using the familiar "tree", "branch", and "leaf" scheme.
Branches represent diversions from general code to more specific code, while leaves
@@ -215,8 +150,8 @@
We will just talk about working with the temporary source code.
For more information on how to get kernel source code onto your
host system, see the
- "<link linkend='local-kernel-files'>Yocto Project Kernel</link>"
- bulleted item earlier in the manual.
+ "<link linkend='local-kernel-files'>Setting Up to Work On a Kernel</link>"
+ section.
</para>
<para>
diff --git a/documentation/kernel-dev/kernel-dev-concepts-appx.xml
b/documentation/kernel-dev/kernel-dev-concepts-appx.xml
index 8ecd04d..3606301 100644
--- a/documentation/kernel-dev/kernel-dev-concepts-appx.xml
+++ b/documentation/kernel-dev/kernel-dev-concepts-appx.xml
@@ -7,80 +7,169 @@
<section id='kernel-big-picture'>
<title>Yocto Project Kernel Development and Maintenance</title>
+
<para>
- Kernels available through the Yocto Project, like other kernels, are based off the Linux
- kernel releases from <ulink url='http://www.kernel.org'></ulink>.
- At the beginning of a major development cycle, the Yocto Project team
- chooses its kernel based on factors such as release timing, the anticipated release
- timing of final upstream <filename>kernel.org</filename> versions, and Yocto Project
+ Kernels available through the Yocto Project (Linux Yocto kernels),
+ like other kernels, are based off the Linux kernel releases from
+ <ulink url='http://www.kernel.org'></ulink>.
+ At the beginning of a major Linux kernel development cycle, the
+ Yocto Project team chooses a Linux kernel based on factors such as
+ release timing, the anticipated release timing of final upstream
+ <filename>kernel.org</filename> versions, and Yocto Project
feature requirements.
- Typically, the kernel chosen is in the
- final stages of development by the community.
- In other words, the kernel is in the release
- candidate or "rc" phase and not yet a final release.
- But, by being in the final stages of external development, the team knows that the
- <filename>kernel.org</filename> final release will clearly be within the early stages of
- the Yocto Project development window.
+ Typically, the Linux kernel chosen is in the final stages of
+ development by the Linux community.
+ In other words, the Linux kernel is in the release candidate
+ or "rc" phase and has yet to reach final release.
+ But, by being in the final stages of external development, the
+ team knows that the <filename>kernel.org</filename> final release
+ will clearly be within the early stages of the Yocto Project
+ development window.
</para>
+
+ <para>
+ This balance allows the Yocto Project team to deliver the most
+ up-to-date Linux Yocto kernel possible, while still ensuring that
+ the team has a stable official release for the baseline Linux
+ kernel version.
+ </para>
+
<para>
- This balance allows the team to deliver the most up-to-date kernel
- possible, while still ensuring that the team has a stable official release for
- the baseline Linux kernel version.
+ As implied earlier, the ultimate source for Linux Yocto kernels
+ are released kernels from <filename>kernel.org</filename>.
+ In addition to a foundational kernel from
+ <filename>kernel.org</filename>, the available Yocto Linux kernels
+ contain a mix of important new mainline developments, non-mainline
+ developments (when there is no alternative), Board Support Package
+ (BSP) developments, and custom features.
+ These additions result in a commercially released Yocto
+ Project Linux kernel that caters to specific embedded designer
+ needs for targeted hardware.
</para>
+
<para>
- The ultimate source for kernels available through the Yocto Project are released kernels
- from <filename>kernel.org</filename>.
- In addition to a foundational kernel from <filename>kernel.org</filename>, the
- kernels available contain a mix of important new mainline
- developments, non-mainline developments (when there is no alternative),
- Board Support Package (BSP) developments,
- and custom features.
- These additions result in a commercially released Yocto Project Linux kernel that caters
- to specific embedded designer needs for targeted hardware.
+ You can find a web interface to the Yocto Linux kernels in the
+ <ulink url='&YOCTO_DOCS_REF_URL;#source-repositories'>Source Repositories</ulink>
+ at
+ <ulink url='&YOCTO_GIT_URL;'></ulink>.
+ If you look at the interface, you will see to the left a
+ grouping of Git repositories titled "Yocto Linux Kernel".
+ Within this group, you will find several Linux Yocto kernels
+ developed and included with Yocto Project releases:
+ <itemizedlist>
+ <listitem><para>
+ <emphasis><filename>linux-yocto-4.1</filename>:</emphasis>
+ The stable Yocto Project kernel to use with the Yocto
+ Project Release 2.0.
+ This kernel is based on the Linux 4.1 released kernel.
+ </para></listitem>
+ <listitem><para>
+ <emphasis><filename>linux-yocto-4.4</filename>:</emphasis>
+ The stable Yocto Project kernel to use with the Yocto
+ Project Release 2.1.
+ This kernel is based on the Linux 4.4 released kernel.
+ </para></listitem>
+ <listitem><para>
+ <emphasis><filename>linux-yocto-4.9</filename>:</emphasis>
+ The stable Yocto Project kernel to use with the Yocto
+ Project Release 2.3.
+ This kernel is based on the Linux 4.9 released kernel.
+ </para></listitem>
+ <listitem><para>
+ <emphasis><filename>linux-yocto-4.10</filename>:</emphasis>
+ The default stable Yocto Project kernel to use with the
+ Yocto Project Release 2.3.
+ This kernel is based on the Linux 4.10 released kernel.
+ </para></listitem>
+ <listitem><para>
+ <emphasis><filename>linux-yocto-dev</filename>:</emphasis>
+ A development kernel based on the latest upstream release
+ candidate available.
+ </para></listitem>
+ </itemizedlist>
+ <note><title>Notes</title>
+ Long Term Support Initiative (LTSI) for Yocto Linux
+ kernels is as follows:
+ <itemizedlist>
+ <listitem><para>
+ For Yocto Project releases 1.7, 1.8, and 2.0,
+ the LTSI kernel is
+ <filename>linux-yocto-3.14</filename>.
+ </para></listitem>
+ <listitem><para>
+ For Yocto Project releases 2.1, 2.2, and 2.3,
+ the LTSI kernel is <filename>linux-yocto-4.1</filename>.
+ </para></listitem>
+ <listitem><para>
+ <filename>linux-yocto-4.1</filename>,
+ <filename>linux-yocto-4.4</filename>, and
+ <filename>linux-yocto-4.9</filename> are all LTS
+ kernels.
+ </para></listitem>
+ </itemizedlist>
+ </note>
</para>
+
<para>
- Once a kernel is officially released, the Yocto Project team goes into
- their next development cycle, or upward revision (uprev) cycle, while still
- continuing maintenance on the released kernel.
+ Once a Yocto Linux kernel is officially released, the Yocto
+ Project team goes into their next development cycle, or upward
+ revision (uprev) cycle, while still continuing maintenance on the
+ released kernel.
It is important to note that the most sustainable and stable way
- to include feature development upstream is through a kernel uprev process.
- Back-porting hundreds of individual fixes and minor features from various
- kernel versions is not sustainable and can easily compromise quality.
+ to include feature development upstream is through a kernel uprev
+ process.
+ Back-porting hundreds of individual fixes and minor features from
+ various kernel versions is not sustainable and can easily
+ compromise quality.
</para>
+
<para>
- During the uprev cycle, the Yocto Project team uses an ongoing analysis of
- kernel development, BSP support, and release timing to select the best
- possible <filename>kernel.org</filename> version.
- The team continually monitors community kernel
- development to look for significant features of interest.
- The team does consider back-porting large features if they have a significant advantage.
- User or community demand can also trigger a back-port or creation of new
- functionality in the Yocto Project baseline kernel during the uprev cycle.
+ During the uprev cycle, the Yocto Project team uses an ongoing
+ analysis of Linux kernel development, BSP support, and release
+ timing to select the best possible <filename>kernel.org</filename>
+ Linux kernel version on which to base subsequent Yocto Linux
+ kernel development.
+ The team continually monitors Linux community kernel development
+ to look for significant features of interest.
+ The team does consider back-porting large features if they have a
+ significant advantage.
+ User or community demand can also trigger a back-port or creation
+ of new functionality in the Yocto Project baseline kernel during
+ the uprev cycle.
</para>
+
<para>
- Generally speaking, every new kernel both adds features and introduces new bugs.
- These consequences are the basic properties of upstream kernel development and are
- managed by the Yocto Project team's kernel strategy.
- It is the Yocto Project team's policy to not back-port minor features to the released kernel.
- They only consider back-porting significant technological jumps - and, that is done
- after a complete gap analysis.
- The reason for this policy is that back-porting any small to medium sized change
- from an evolving kernel can easily create mismatches, incompatibilities and very
- subtle errors.
+ Generally speaking, every new Linux kernel both adds features and
+ introduces new bugs.
+ These consequences are the basic properties of upstream
+ Linux kernel development and are managed by the Yocto Project
+ team's Linux Yocto kernel development strategy.
+ It is the Yocto Project team's policy to not back-port minor
+ features to the released Linux Yocto kernel.
+ They only consider back-porting significant technological
+ jumps ‐ and, that is done after a complete gap analysis.
+ The reason for this policy is that back-porting any small to
+ medium sized change from an evolving Linux kernel can easily
+ create mismatches, incompatibilities and very subtle errors.
</para>
+
<para>
- These policies result in both a stable and a cutting
- edge kernel that mixes forward ports of existing features and significant and critical
- new functionality.
- Forward porting functionality in the kernels available through the Yocto Project kernel
- can be thought of as a "micro uprev."
- The many “micro uprevs” produce a kernel version with a mix of
- important new mainline, non-mainline, BSP developments and feature integrations.
- This kernel gives insight into new features and allows focused
- amounts of testing to be done on the kernel, which prevents
- surprises when selecting the next major uprev.
- The quality of these cutting edge kernels is evolving and the kernels are used in leading edge
- feature and BSP development.
+ The policies described in this section result in both a stable
+ and a cutting edge Linux Yocto kernel that mixes forward ports of
+ existing Linux kernel features and significant and critical new
+ functionality.
+ Forward porting Linux kernel functionality into the Linux Yocto
+ kernels available through the Yocto Project can be thought of as
+ a "micro uprev."
+ The many “micro uprevs” produce a Linux Yocto kernel version with
+ a mix of important new mainline, non-mainline, BSP developments
+ and feature integrations.
+ This Yocto Linux kernel gives insight into new features and
+ allows focused amounts of testing to be done on the kernel,
+ which prevents surprises when selecting the next major uprev.
+ The quality of these cutting edge Linux Yocto kernels is evolving
+ and the kernels are used in leading edge feature and BSP
+ development.
</para>
</section>
[
Date Prev][
Date Next] [
Thread Prev][
Thread Next]
[
Thread Index]
[
Date Index]
[
Author Index]
