Merge branch 'for-2.6.39' of git://linux-nfs.org/~bfields/linux

[pandora-kernel.git] / Documentation / devicetree / booting-without-of.txt

diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt
index 28b1c9d..50619a0 100644 (file)
--- a/Documentation/devicetree/booting-without-of.txt
+++ b/Documentation/devicetree/booting-without-of.txt
@@ -13,6 +13,7 @@ Table of Contents
 
   I - Introduction
     1) Entry point for arch/powerpc
+    2) Entry point for arch/x86
 
   II - The DT block format
     1) Header
@@ -137,7 +138,7 @@ and properties to be present. This will be described in detail in
 section III, but, for example, the kernel does not require you to
 create a node for every PCI device in the system. It is a requirement
 to have a node for PCI host bridges in order to provide interrupt
-routing informations and memory/IO ranges, among others. It is also
+routing information and memory/IO ranges, among others. It is also
 recommended to define nodes for on chip devices and other buses that
 don't specifically fit in an existing OF specification. This creates a
 great flexibility in the way the kernel can then probe those and match
@@ -225,6 +226,25 @@ it with special cases.
   cannot support both configurations with Book E and configurations
   with classic Powerpc architectures.
 
+2) Entry point for arch/x86
+-------------------------------
+
+  There is one single 32bit entry point to the kernel at code32_start,
+  the decompressor (the real mode entry point goes to the same  32bit
+  entry point once it switched into protected mode). That entry point
+  supports one calling convention which is documented in
+  Documentation/x86/boot.txt
+  The physical pointer to the device-tree block (defined in chapter II)
+  is passed via setup_data which requires at least boot protocol 2.09.
+  The type filed is defined as
+
+  #define SETUP_DTB                      2
+
+  This device-tree is used as an extension to the "boot page". As such it
+  does not parse / consider data which is already covered by the boot
+  page. This includes memory size, reserved ranges, command line arguments
+  or initrd address. It simply holds information which can not be retrieved
+  otherwise like interrupt routing or a list of devices behind an I2C bus.
 
 II - The DT block format
 ========================
@@ -365,7 +385,7 @@ struct boot_param_header {
      among others, by kexec. If you are on an SMP system, this value
      should match the content of the "reg" property of the CPU node in
      the device-tree corresponding to the CPU calling the kernel entry
-     point (see further chapters for more informations on the required
+     point (see further chapters for more information on the required
      device-tree contents)
 
    - size_dt_strings
@@ -533,7 +553,7 @@ looks like in practice.
 
 This tree is almost a minimal tree. It pretty much contains the
 minimal set of required nodes and properties to boot a linux kernel;
-that is, some basic model informations at the root, the CPUs, and the
+that is, some basic model information at the root, the CPUs, and the
 physical memory layout.  It also includes misc information passed
 through /chosen, like in this example, the platform type (mandatory)
 and the kernel command line arguments (optional).