A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-29 19:21:31 -04:00
Code Issues Projects Releases Packages Wiki Activity

x86: Add device tree support

Browse source 
This patch adds minimal support for device tree on x86. The device
tree blob is passed to the kernel via setup_data which requires at
least boot protocol 2.09.

Memory size, restricted memory regions, boot arguments are gathered
the traditional way so things like cmd_line are just here to let the
code compile.

The current plan is use the device tree as an extension and to gather
information which can not be enumerated and would have to be hardcoded
otherwise. This includes things like 
   - which devices are on this I2C/SPI bus?
   - how are the interrupts wired to IO APIC?
   - where could my hpet be?

Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Dirk Brandewie <[email protected]>
Acked-by: Grant Likely <[email protected]>
Cc: [email protected]
Cc: [email protected]
LKML-Reference: <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
This commit is contained in:
Sebastian Andrzej Siewior 2011-02-22 21:07:37 +01:00 • committed by Thomas Gleixner
commit da6b737b9a
9 changed files with 126 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

20
Documentation/devicetree/booting-without-of.txt
View file

@ -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
========================