path: root/docs
diff options
Diffstat (limited to 'docs')
1 files changed, 24 insertions, 0 deletions
diff --git a/docs/usermanual/chapters/common_use_cases.xml b/docs/usermanual/chapters/common_use_cases.xml
index d86d0ca8d1..ef81b95fa9 100644
--- a/docs/usermanual/chapters/common_use_cases.xml
+++ b/docs/usermanual/chapters/common_use_cases.xml
@@ -94,6 +94,30 @@ SRCDATE = "20061014"
+ <para>There are also some optional variables that can be defined:
+ <itemizedlist>
+ <listitem>
+ <para><command>SOC_FAMILY</command> describes a family of processors
+ that all share common features such as kernel versions,
+ bootloaders, etc. This is used to allow overrides for a whole
+ set of devices rather than per machine overrides being used.
+ The use of SOC_FAMILY as an override is currently a distribution
+ or local setting.
+ </para>
+ <para>
+ NOTE: SOC_FAMILY is different than MACHINE_CLASS in that
+ MACHINE_CLASS is intended to specify a grouping of devices
+ that may have different processors but share common features.
+ For example all OMAP3 devices can be described using the SOC_FAMILY
+ "omap3" and this value can be used in overrides to prevent
+ requiring multiple machine specific overrides. MACHINE_CLASS
+ might be used to describe a class of devices such as a cell
+ phone in which the processor may be different but the
+ features such as touchscreen, GPS, modem, etc are the same.
+ </para>
+ </listitem>
+ </itemizedlist></para>
<para>Next the kernel recipe needs to be added if it doesn't already exist.