[yocto] [yocto-docs][PATCH 2/2] dev-manual: Add section about /dev population
Bach, Pascal
pascal.bach at siemens.com
Mon Jan 19 00:30:29 PST 2015
Hi Scott
Thanks. I had a look at the commits and it looks like commit 7c6c7ac573f92bfc844977e0d7a97ca4aac9bc70 also introduced a strange change on line 946 of dev-manual-common-tasks.xml.
See: https://git.yoctoproject.org/cgit/cgit.cgi/yocto-docs/commit/?id=7c6c7ac573f92bfc844977e0d7a97ca4aac9bc70
Pascal
> -----Original Message-----
> From: Rifenbark, Scott M [mailto:scott.m.rifenbark at intel.com]
> Sent: Samstag, 17. Januar 2015 01:05
> To: Bach, Pascal; yocto at yoctoproject.org
> Subject: RE: [yocto] [yocto-docs][PATCH 2/2] dev-manual: Add section
> about /dev population
>
> Pascal,
>
> I have applied this patch with some editing. Also, applied the patch
> that added the USE_DEVFS variable to the ref-manual.
>
> Thanks,
> Scott
>
> >-----Original Message-----
> >From: yocto-bounces at yoctoproject.org [mailto:yocto-
> >bounces at yoctoproject.org] On Behalf Of Pascal Bach
> >Sent: Wednesday, January 07, 2015 6:58 AM
> >To: yocto at yoctoproject.org
> >Subject: [yocto] [yocto-docs][PATCH 2/2] dev-manual: Add section about
> >/dev population
> >
> >Signed-off-by: Pascal Bach <pascal.bach at siemens.com>
> >---
> > .../dev-manual/dev-manual-common-tasks.xml | 104
> >++++++++++++++++++++
> > 1 file changed, 104 insertions(+)
> >
> >diff --git a/documentation/dev-manual/dev-manual-common-tasks.xml
> >b/documentation/dev-manual/dev-manual-common-tasks.xml
> >index 17d725b..9072586 100644
> >--- a/documentation/dev-manual/dev-manual-common-tasks.xml
> >+++ b/documentation/dev-manual/dev-manual-common-tasks.xml
> >@@ -7582,6 +7582,110 @@ Gateways via their Web
> >Interfaces</ulink>"</emphasis>
> > </section>
> > </section>
> >
> >+ <section id="selecting-dev-manager">
> >+ <title>Selecting a Device Manager</title>
> >+
> >+ <para>
> >+ Yocto provides multiple ways to manage
> <filename>/dev</filename>
> >+ <itemizedlist>
> >+ <listitem><para>
> >+ <emphasis>Persistent and pre populated
> ><filename>/dev</filename>:</emphasis>
> >+ in this case the <filename>/dev</filename> directory
> is persistent
> >+ and the required device nodes are created at build
> time.
> >+ </para></listitem>
> >+
> >+ <listitem><para>
> >+ <emphasis>Use <filename>devtmps</filename> with a
> device
> >manager:</emphasis>
> >+ in this case the <filename>/dev</filename> directory
> is provided
> >+ by the kernel as an in memory file system and is
> automatically
> >+ populated by the kernel at runtime. Additional
> configuration of
> >+ device nodes is done in user space by a device manager
> like
> >+ <filename>udev</filename> or <filename>busybox-
> >mdev</filename>.
> >+ </para></listitem>
> >+ </itemizedlist>
> >+ </para>
> >+
> >+ <section id="static-dev-management">
> >+ <title>Use Persistent and pre-populated
> ><filename>/dev</filename></title>
> >+
> >+ <para>
> >+ To use the static method for device population the
> variable
> >+ <ulink url='&YOCTO_DOCS_REF_URL;#var-
> >USE_DEVFS'><filename>USE_DEVFS</filename></ulink>
> >+ needs to be set to 0.
> >+
> >+ <literallayout class='monospaced'>
> >+ USE_DEVFS = "0"
> >+ </literallayout>
> >+ </para>
> >+
> >+ <para>
> >+ The content of the resulting <filename>/dev</filename>
> directory
> >+ is defined in a Device Table file. The device table to
> use is defined by
> >the variable
> >+ <ulink url='&YOCTO_DOCS_REF_URL;#var-
> >IMAGE_DEVICE_TABLES'><filename>IMAGE_DEVICE_TABLES</filename></ul
> >ink> and should be set
> >+ in the <ulink url='&YOCTO_DOCS_REF_URL;#var-
> >MACHINE'><filename>MACHINE</filename></ulink>,
> >+ <ulink url='&YOCTO_DOCS_REF_URL;#var-
> >DISTRO'><filename>DISTRO</filename></ulink>
> >+ or <filename>local.conf</filename> configuration file.
> >+ </para>
> >+
> >+ <para>
> >+ If nothing is defined the default
> <filename>device_table-
> >minimal.txt</filename> is used.
> >+ </para>
> >+
> >+ <para>
> >+ The population is handled by the
> <filename>makedevs</filename>
> >utility
> >+ during image creation.
> >+
> >+ <literallayout class='monospaced'>
> >+ IMAGE_DEVICE_TABLES = "device_table-mymachine.txt"
> >+ </literallayout>
> >+
> >+ </para>
> >+ </section>
> >+
> >+ <section id="devtmps-dev-management">
> >+ <title>Use <filename>devtmpfs</filename> and a device
> >manager</title>
> >+
> >+ <para>
> >+ To use the dynamic method for device population the
> variable
> >+ <ulink url='&YOCTO_DOCS_REF_URL;#var-
> >USE_DEVFS'><filename>USE_DEVFS</filename></ulink>
> >+ needs to be set to 1. This is the default.
> >+
> >+ <literallayout class='monospaced'>
> >+ USE_DEVFS = "1"
> >+ </literallayout>
> >+
> >+ This way the resulting <filename>/dev</filename> is
> populated by
> >the kernel
> >+ using <filename>devtmpfs</filename>. Make sure the
> >corresponding
> >+ kernel configuration variable
> ><filename>CONFIG_DEVTMPFS</filename> is set
> >+ when building a linux kernel.
> >+
> >+ </para>
> >+ <para>
> >+ All devices created by <filename>devtmpfs</filename>
> will be
> >+ owned by <filename>root</filename> and have
> permissions
> ><filename>0600</filename>.
> >+
> >+ To have more control over the device nodes a device
> manager like
> >+ <filename>udev</filename> or <filename>busybox-
> >mdev</filename>
> >+ can be used.
> >+
> >+ The device manager to use is defined by the variable
> >+ <filename>VIRTUAL-RUNTIME_dev_manager</filename> and
> >should be set
> >+ in the <ulink url='&YOCTO_DOCS_REF_URL;#var-
> >MACHINE'><filename>MACHINE</filename></ulink>,
> >+ <ulink url='&YOCTO_DOCS_REF_URL;#var-
> >DISTRO'><filename>DISTRO</filename></ulink>
> >+ or <filename>local.conf</filename> configuration file.
> >+
> >+ <literallayout class='monospaced'>
> >+
> >+ VIRTUAL-RUNTIME_dev_manager = "udev"
> >+
> >+ # Some alternative values
> >+ # VIRTUAL-RUNTIME_dev_manager = "busybox-mdev"
> >+ # VIRTUAL-RUNTIME_dev_manager = "systemd"
> >+ </literallayout>
> >+ </para>
> >+ </section>
> >+ </section>
> >+
> > <section id="platdev-appdev-srcrev">
> > <title>Using an External SCM</title>
> >
> >--
> >1.7.10.4
> >
> >--
> >_______________________________________________
> >yocto mailing list
> >yocto at yoctoproject.org
> >https://lists.yoctoproject.org/listinfo/yocto
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