Documentation: arm: Update for DT-only platforms
The documentation specified that a machine type is mandatory and made
that assumption in a few places. However, for DT-only platforms, the
current advice is that no machine type should be registered, so update
accordingly.
Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/arm/Booting b/Documentation/arm/Booting
index 371814a..83c1df2 100644
--- a/Documentation/arm/Booting
+++ b/Documentation/arm/Booting
@@ -58,13 +58,18 @@
--------------------------
Existing boot loaders: OPTIONAL
-New boot loaders: MANDATORY
+New boot loaders: MANDATORY except for DT-only platforms
The boot loader should detect the machine type its running on by some
method. Whether this is a hard coded value or some algorithm that
looks at the connected hardware is beyond the scope of this document.
The boot loader must ultimately be able to provide a MACH_TYPE_xxx
-value to the kernel. (see linux/arch/arm/tools/mach-types).
+value to the kernel. (see linux/arch/arm/tools/mach-types). This
+should be passed to the kernel in register r1.
+
+For DT-only platforms, the machine type will be determined by device
+tree. set the machine type to all ones (~0). This is not strictly
+necessary, but assures that it will not match any existing types.
4. Setup boot data
------------------