Re: [docs][PATCH] kernel-dev: Add FAQ for how to use a vanilla kernel

["Quentin Schulz" <foss@0leil.net>]

Hi Joshua,



On October 20, 2020 7:03:26 PM GMT+02:00, Joshua Watt <JPEWhacker@gmail.com> wrote:
>Adds a FAQ with explicit directions about how to build a vanilla kernel
>for a machine.
>
>Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
>---
> documentation/kernel-dev/kernel-dev-faq.rst | 49 +++++++++++++++++++++
> 1 file changed, 49 insertions(+)
>
>diff --git a/documentation/kernel-dev/kernel-dev-faq.rst
>b/documentation/kernel-dev/kernel-dev-faq.rst
>index 70bf4a2d4..929cc4aad 100644
>--- a/documentation/kernel-dev/kernel-dev-faq.rst
>+++ b/documentation/kernel-dev/kernel-dev-faq.rst
>@@ -79,3 +79,52 @@ following:
> 
>    APPEND += "printk.time=y initcall_debug debug"
> 
>+How do I use a vanilla Linux kernel with my machine?
>+----------------------------------------------------
>+
>+The simplest way to use a vanilla kernel is with the ``linux-yocto``
>kernel
>+maintained by openembedded-core. Using this kernel is as simple as
>adding the
>+following to your machine.conf file:
>+::
>+
>+   # Use a defconfig provided by the kernel. If you are going to
>provide your
>+   # own defconfig in SRC_URI as show below, you'll need to omit this

s/show/shown/

>line
>+   KBUILD_DEFCONFIG = "multi_v7_defconfig"
>+
>+   # Use default value for all symbols. This is usually what you want
>when
>+   # providing a defconfig
>+   KCONFIG_MODE = "alldefconfig"
>+

KCONFIG_MODE is not explained in the Variables Glossary, could you please fix that?

>+   # Make linux-yocto provide the kernel
>+   PREFERRED_PROVIDER_virtual/kernel = "linux-yocto"
>+
>+   # If you want to use a specific version of the upstream kernel,
>uncomment
>+   # and set this line, otherwise omit it to use the latest stable
>kernel

Here's to hoping that no layer with a higher priority provide their own linux-yocto :)

>+   #PREFERRED_VERSION_linux-yocto = "5.8.%"
>+
>+You will also need to add a .bbappend in your BSP layer to amend the
>+linux-yocto recipe (e.g. recipes-kernel/linux/linux-yocto_%.bbappend):

``linux-yocto`` and the path in double tick too.

>+::
>+
>+    FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
>+
>+    # Uncomment this line to provide your own defconfig file in your
>BSP layer:
>+    # SRC_URI_append_my-machine = " file://defconfig"
>+
>+    # Marks the recipe as compatible with your machine. Be sure to
>replace
>+    # my-machine with the name of your machine
>+    COMPATIBLE_MACHINE .= "|my-machine"
>+

I don't think spaces matter in COMPATIBLE_MACHINE but happy to be proven otherwise. In that case, probably += would be better as it's usually what's used throughout the docs? As to not confuse beginners?

>+You can also apply patches and config fragements in the bbappend if
s/fragements/fragments/
>desired,
>+see :ref:`kernel-dev/kernel-dev-common:applying patches` and
>+:ref:`kernel-dev/kernel-dev-common:changing the configuration` in the
>Kernel
>+dev manual. It is recommended that you use ``_append_my-machine`` to
>prevent
>+these changes from inadverently leaking into other machine
>configurations

Missing dot at the end of the sentence.

>+
>+.. note::
>+    You will notice that this is will still pull the kernel source

Not a native, but my doubts on "you will notice" being correct?

s/is//

>from `the
>+    Yocto Kernel git repo
>+    <https://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto/>`_,

:yocto_git:`the Yocto Kernel git repo </cgit/cgit.cgi/linux-yocto/>`

Thanks,
Quentin
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.