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authorGrant Likely <grant.likely@secretlab.ca>2011-02-14 10:13:20 -0500
committerGrant Likely <grant.likely@secretlab.ca>2011-02-14 10:13:20 -0500
commit7211da17785536bacd3171a28bc6a3853c8bb477 (patch)
tree958adbdd76ff67b29c2429ad63478675a75e00e4 /Documentation/devicetree
parent9830fcd6f6a4781d8b46d2b35c13b39f30915c63 (diff)
Revert "dt: add documentation of ARM dt boot interface"
This reverts commit 9830fcd6f6a4781d8b46d2b35c13b39f30915c63. The ARM dt support has not been merged yet; this documentation update was premature. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/booting-without-of.txt40
1 files changed, 0 insertions, 40 deletions
diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt
index 9381a148102..28b1c9d3d35 100644
--- a/Documentation/devicetree/booting-without-of.txt
+++ b/Documentation/devicetree/booting-without-of.txt
@@ -13,7 +13,6 @@ Table of Contents
13 13
14 I - Introduction 14 I - Introduction
15 1) Entry point for arch/powerpc 15 1) Entry point for arch/powerpc
16 2) Entry point for arch/arm
17 16
18 II - The DT block format 17 II - The DT block format
19 1) Header 18 1) Header
@@ -226,45 +225,6 @@ it with special cases.
226 cannot support both configurations with Book E and configurations 225 cannot support both configurations with Book E and configurations
227 with classic Powerpc architectures. 226 with classic Powerpc architectures.
228 227
2292) Entry point for arch/arm
230---------------------------
231
232 There is one single entry point to the kernel, at the start
233 of the kernel image. That entry point supports two calling
234 conventions. A summary of the interface is described here. A full
235 description of the boot requirements is documented in
236 Documentation/arm/Booting
237
238 a) ATAGS interface. Minimal information is passed from firmware
239 to the kernel with a tagged list of predefined parameters.
240
241 r0 : 0
242
243 r1 : Machine type number
244
245 r2 : Physical address of tagged list in system RAM
246
247 b) Entry with a flattened device-tree block. Firmware loads the
248 physical address of the flattened device tree block (dtb) into r2,
249 r1 is not used, but it is considered good practise to use a valid
250 machine number as described in Documentation/arm/Booting.
251
252 r0 : 0
253
254 r1 : Valid machine type number. When using a device tree,
255 a single machine type number will often be assigned to
256 represent a class or family of SoCs.
257
258 r2 : physical pointer to the device-tree block
259 (defined in chapter II) in RAM. Device tree can be located
260 anywhere in system RAM, but it should be aligned on a 32 bit
261 boundary.
262
263 The kernel will differentiate between ATAGS and device tree booting by
264 reading the memory pointed to by r1 and looking for either the flattened
265 device tree block magic value (0xd00dfeed) or the ATAG_CORE value at
266 offset 0x4 from r2 (0x54410001).
267
268 228
269II - The DT block format 229II - The DT block format
270======================== 230========================