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-boun...@yoctoproject.org [mailto:yocto- >boun...@yoctoproject.org] On Behalf Of Pascal Bach >Sent: Wednesday, January 07, 2015 6:58 AM >To: yocto@yoctoproject.org >Subject: [yocto] [yocto-docs][PATCH 2/2] dev-manual: Add section about >/dev population > >Signed-off-by: Pascal Bach <pascal.b...@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@yoctoproject.org >https://lists.yoctoproject.org/listinfo/yocto -- _______________________________________________ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto