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authorGrant Likely <grant.likely@secretlab.ca>2011-03-17 13:46:58 -0600
committerGrant Likely <grant.likely@secretlab.ca>2011-03-17 13:48:06 -0600
commit2dd22997679a88874c131f6e6ffb963e6d43b3a6 (patch)
treebfe1707dda7e755b8b550c6796e2649813bcfbb9 /Documentation/devicetree/booting-without-of.txt
parent36885ff0e6563687e6152da6d311abbf83c0198f (diff)
parent7b7adc4a016a1decb806eb71ecab98721fa7f146 (diff)
downloadop-kernel-dev-2dd22997679a88874c131f6e6ffb963e6d43b3a6.zip
op-kernel-dev-2dd22997679a88874c131f6e6ffb963e6d43b3a6.tar.gz
Merge remote-tracking branch 'origin' into spi/next
Pull in Linus' tree to pick up changes required for the langwell gpio fixes
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diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt
index 28b1c9d..55fd262 100644
--- 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
@@ -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
========================
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