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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-18 11:10:49 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-18 11:10:49 -0400
commitd6a24d0640d609138a4e40a4ce9fd9fe7859e24c (patch)
treeaa40fb7f5d03dc605634fb4030afd8798bd6bc0b /Documentation/arm
parent1f5014d6a77513fa7cefe30eb7791d5856c04384 (diff)
parent197175427a221fe3200f7727ea35e261727e7228 (diff)
downloadlinux-d6a24d0640d609138a4e40a4ce9fd9fe7859e24c.tar.gz
linux-d6a24d0640d609138a4e40a4ce9fd9fe7859e24c.tar.xz
Merge tag 'docs-for-linus' of git://git.lwn.net/linux-2.6
Pull documentation updates from Jonathan Corbet: "Numerous fixes, the overdue removal of the i2o docs, some new Chinese translations, and, hopefully, the README fix that will end the flow of identical patches to that file" * tag 'docs-for-linus' of git://git.lwn.net/linux-2.6: (34 commits) Documentation/memcg: update memcg/kmem status Documentation: blackfin: Makefile: Typo building issue Documentation/vm/pagemap.txt: correct location of page-types tool Documentation/memory-barriers.txt: typo fix doc: Add guest_nice column to example output of `cat /proc/stat' Documentation/kernel-parameters: Move "eagerfpu" to its right place Documentation: gpio: Update ACPI part of the document to mention _DSD docs/completion.txt: Various tweaks and corrections doc: completion: context, scope and language fixes Documentation:Update Documentation/zh_CN/arm64/memory.txt Documentation:Update Documentation/zh_CN/arm64/booting.txt Documentation: Chinese translation of arm64/legacy_instructions.txt DocBook media: fix broken EIA hyperlink Documentation: tweak the maintainers entry README: Change gzip/bzip2 to xz compression format README: Update version number reference doc:pci: Fix typo in Documentation/PCI Documentation: drm: Use '->' when describing access through pointers. Documentation: Remove mentioning of block barriers Documentation/email-clients.txt: Fix one grammar mistake, add extra info about TB ...
Diffstat (limited to 'Documentation/arm')
-rw-r--r--Documentation/arm/Booting9
-rw-r--r--Documentation/arm/README15
2 files changed, 18 insertions, 6 deletions
diff --git a/Documentation/arm/Booting b/Documentation/arm/Booting
index 371814a36719..83c1df2fc758 100644
--- a/Documentation/arm/Booting
+++ b/Documentation/arm/Booting
@@ -58,13 +58,18 @@ serial format options as described in
--------------------------
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
------------------
diff --git a/Documentation/arm/README b/Documentation/arm/README
index aea34095cdcf..9d1e5b2c92e6 100644
--- a/Documentation/arm/README
+++ b/Documentation/arm/README
@@ -185,13 +185,20 @@ Kernel entry (head.S)
board devices are used, or the device is setup, and provides that
machine specific "personality."
- This fine-grained machine specific selection is controlled by the machine
- type ID, which acts both as a run-time and a compile-time code selection
- method.
+ For platforms that support device tree (DT), the machine selection is
+ controlled at runtime by passing the device tree blob to the kernel. At
+ compile-time, support for the machine type must be selected. This allows for
+ a single multiplatform kernel build to be used for several machine types.
- You can register a new machine via the web site at:
+ For platforms that do not use device tree, this machine selection is
+ controlled by the machine type ID, which acts both as a run-time and a
+ compile-time code selection method. You can register a new machine via the
+ web site at:
<http://www.arm.linux.org.uk/developer/machines/>
+ Note: Please do not register a machine type for DT-only platforms. If your
+ platform is DT-only, you do not need a registered machine type.
+
---
Russell King (15/03/2004)