| Message ID | 20110131074510.9058.59071.stgit@localhost6.localdomain6 (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Mon, Jan 31, 2011 at 12:45:41AM -0700, Grant Likely wrote: >Signed-off-by: Grant Likely <grant.likely@secretlab.ca> >--- > >For RFC only. I do not plan to merge this change yet. > >g. > > Documentation/devicetree/booting-without-of.txt | 40 +++++++++++++++++++++++ > 1 files changed, 40 insertions(+), 0 deletions(-) > >diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt >index 6bca668..3950aea 100644 >--- a/Documentation/devicetree/booting-without-of.txt >+++ b/Documentation/devicetree/booting-without-of.txt >@@ -232,6 +233,45 @@ it with special cases. > cannot support both configurations with Book E and configurations > with classic Powerpc architectures. > >+2) Entry point for arch/arm >+--------------------------- >+ >+ There is one and one single entry point to the kernel, at the start "one and one" ? josh
> -----Original Message----- > From: linuxppc-dev-bounces+stephen=neuendorffer.name@lists.ozlabs.org [mailto:linuxppc-dev- > bounces+stephen=neuendorffer.name@lists.ozlabs.org] On Behalf Of Grant Likely > Sent: Sunday, January 30, 2011 11:46 PM > To: devicetree-discuss@lists.ozlabs.org; linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org > Cc: sam@ravnborg.org > Subject: [PATCH 3/3 RFC] dt: add documentation of ARM dt boot interface > > Signed-off-by: Grant Likely <grant.likely@secretlab.ca> > --- > > For RFC only. I do not plan to merge this change yet. > > g. > > Documentation/devicetree/booting-without-of.txt | 40 +++++++++++++++++++++++ > 1 files changed, 40 insertions(+), 0 deletions(-) > > diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting- > without-of.txt > index 6bca668..3950aea 100644 > --- a/Documentation/devicetree/booting-without-of.txt > +++ b/Documentation/devicetree/booting-without-of.txt In order to make this more generic, perhaps it should change names, so that it is actually a description of what the file describes, as opposed to what it doesn't describe. "booting.txt"? > @@ -13,6 +13,7 @@ Table of Contents > > I - Introduction > 1) Entry point for arch/powerpc > + 2) Entry point for arch/arm We should probably include microblaze here too... Steve This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.
On Mon, Jan 31, 2011 at 11:00 AM, Stephen Neuendorffer <stephen.neuendorffer@xilinx.com> wrote: > > >> -----Original Message----- >> From: linuxppc-dev-bounces+stephen=neuendorffer.name@lists.ozlabs.org > [mailto:linuxppc-dev- >> bounces+stephen=neuendorffer.name@lists.ozlabs.org] On Behalf Of Grant > Likely >> Sent: Sunday, January 30, 2011 11:46 PM >> To: devicetree-discuss@lists.ozlabs.org; > linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org >> Cc: sam@ravnborg.org >> Subject: [PATCH 3/3 RFC] dt: add documentation of ARM dt boot > interface >> >> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> >> --- >> >> For RFC only. I do not plan to merge this change yet. >> >> g. >> >> Documentation/devicetree/booting-without-of.txt | 40 > +++++++++++++++++++++++ >> 1 files changed, 40 insertions(+), 0 deletions(-) >> >> diff --git a/Documentation/devicetree/booting-without-of.txt > b/Documentation/devicetree/booting- >> without-of.txt >> index 6bca668..3950aea 100644 >> --- a/Documentation/devicetree/booting-without-of.txt >> +++ b/Documentation/devicetree/booting-without-of.txt > > In order to make this more generic, perhaps it should change names, so > that it is actually a description of what the file > describes, as opposed to what it doesn't describe. "booting.txt"? I though about that, but I think I'd like to leave it as-is for the time being so that it is easier for people to find where it has moved to. > >> @@ -13,6 +13,7 @@ Table of Contents >> >> I - Introduction >> 1) Entry point for arch/powerpc >> + 2) Entry point for arch/arm > > We should probably include microblaze here too... Awesome, thanks for volunteering to write the patch! :-) g.
diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt index 6bca668..3950aea 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/arm II - The DT block format 1) Header @@ -232,6 +233,45 @@ it with special cases. cannot support both configurations with Book E and configurations with classic Powerpc architectures. +2) Entry point for arch/arm +--------------------------- + + There is one and one single entry point to the kernel, at the start + of the kernel image. That entry point supports two calling + conventions. A summary of the interface is described here. A full + description of the boot requirements is documented in + Documentation/arm/Booting + + a) ATAGS interface. Minimal information is passed from firmware + to the kernel with a tagged list of predefined parameters. + + r0 : 0 + + r1 : Machine type number + + r2 : Physical address of tagged list in system RAM + + b) Entry with a flattened device-tree block. Firmware loads the + physical address of the flattened device tree block (dtb) into r2, + r1 is not used, but it is considered good practise to use a valid + machine number as described in Documentation/arm/Booting. + + r0 : 0 + + r1 : Valid machine type number. When using a device tree, + a single machine type number will often be assigned to + represent a class or family of SoCs. + + r2 : physical pointer to the device-tree block + (defined in chapter II) in RAM. Device tree can be located + anywhere in system RAM, but it should be aligned on a 32 bit + boundary. + + The kernel will differentiate between ATAGS and device tree booting by + reading the memory pointed to by r1 and looking for either the flattened + device tree block magic value (0xd00dfeed) or the ATAG_CORE value at + offset 0x4 from r2 (0x54410001). + II - The DT block format ========================
Signed-off-by: Grant Likely <grant.likely@secretlab.ca> --- For RFC only. I do not plan to merge this change yet. g. Documentation/devicetree/booting-without-of.txt | 40 +++++++++++++++++++++++ 1 files changed, 40 insertions(+), 0 deletions(-)