From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Mon, 27 Oct 2014 10:24:11 -0400 Subject: [U-Boot] [PATCH v2 04/11] fdt: Add device tree memory bindings In-Reply-To: References: <1414112337-22735-1-git-send-email-sjg@chromium.org> <1414112337-22735-4-git-send-email-sjg@chromium.org> <20141024184901.GE25506@bill-the-cat> Message-ID: <20141027142411.GV25506@bill-the-cat> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Fri, Oct 24, 2014 at 02:04:00PM -0600, Simon Glass wrote: > Hi Tom, > > On 24 October 2014 12:49, Tom Rini wrote: > > On Thu, Oct 23, 2014 at 06:58:50PM -0600, Simon Glass wrote: > > > >> From: Michael Pratt > >> > >> Support a default memory bank, specified in reg, as well as > >> board-specific memory banks in subtree board-id nodes. > >> > >> This allows memory information to be provided in the device tree, > >> rather than hard-coded in, which will make it simpler to handle > >> similar devices with different memory banks, as the board-id values > >> or masks can be used to match devices. > > [snip] > >> +++ b/doc/device-tree-bindings/memory/memory.txt > >> @@ -0,0 +1,67 @@ > >> +* Memory binding > >> + > >> +The memory binding for U-Boot is as in the ePAPR with the following additions: > > > > I am wary of being different from ePAPR / Linux Kernel. What do we need > > this for / when do we use it? > > This extends the existing binding. It allows the location and size of > memory to be set by a board ID. Unfortunately on sopme hardware you > get a hang if you try to access memory that doesn't exist, so this > allows the range of available memory to be defined - or at least the > maximum bound since we still probe the memory size within that range. > > This feature is used on several Exynos Chromebooks. So that you can use the same DT on several disjoint boards? How does this work with the kernel, does U-Boot then pass along only the correct map? Patches to the kernel to also deal with this? -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: