Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756023AbaFPUSE (ORCPT ); Mon, 16 Jun 2014 16:18:04 -0400 Received: from mail-pd0-f171.google.com ([209.85.192.171]:49844 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755816AbaFPUSC (ORCPT ); Mon, 16 Jun 2014 16:18:02 -0400 From: Julius Werner To: Olof Johansson Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Stephen Warren , Doug Anderson , Stefan Reinauer , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Julius Werner Subject: [PATCH v2] firmware: Add device tree binding for coreboot Date: Mon, 16 Jun 2014 13:17:34 -0700 Message-Id: <1402949854-30380-1-git-send-email-jwerner@chromium.org> X-Mailer: git-send-email 2.0.0.526.g5318336 In-Reply-To: References: <1402689965-19397-1-git-send-email-jwerner@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds documentation describing a device tree binding for the coreboot firmware. It is meant to be dynamically added during boot and contains address definitions for the coreboot table (a list of variable-sized descriptors providing information about various compile- and run-time generated firmware parameters) and the CBMEM area (the structure containing most run-time resident memory regions set up by coreboot). These definitions allow kernel drivers to easily access data contained in and pointed to by these regions (such as coreboot's in-memory log). (An example implementation can be seen at http://crosreview.com/203371, which will be submitted at a later point.) Change-Id: I97609d461d306f85851e5efc26c675ca1e2d7e9d Signed-off-by: Julius Werner --- .../devicetree/bindings/firmware/coreboot.txt | 32 ++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 Documentation/devicetree/bindings/firmware/coreboot.txt diff --git a/Documentation/devicetree/bindings/firmware/coreboot.txt b/Documentation/devicetree/bindings/firmware/coreboot.txt new file mode 100644 index 0000000..5055f0e --- /dev/null +++ b/Documentation/devicetree/bindings/firmware/coreboot.txt @@ -0,0 +1,32 @@ +COREBOOT firmware information + +The device tree node to communicate the location of coreboot's memory-resident +bookkeeping structures to the kernel. Since coreboot itself cannot boot a +device-tree-based kernel (yet), this node needs to be inserted by a +second-stage bootloader (a coreboot "payload"). + +Required properties: + - compatible: Should be "coreboot" + - reg: Address and length of the following two memory regions, in order: + 1.) The coreboot table. This is a list of variable-sized descriptors + that contain various compile- and run-time generated firmware + parameters. It is identified by the magic string "LBIO" in its first + four bytes. See coreboot's src/include/boot/coreboot_tables.h for + details. + 2.) The CBMEM area. This is a downward-growing memory region used by + coreboot to dynamically allocate data structures that remain resident. + It may or may not include the coreboot table as one of its members. It + is identified by a root node descriptor with the magic number + 0xc0389479 that resides in the topmost 8 bytes of the area. See + coreboot's src/lib/dynamic_cbmem.c for details. + +Example: + firmware { + ranges; + + coreboot { + compatible = "coreboot"; + reg = <0xfdfea000 0x264>, + <0xfdfea000 0x16000>; + } + }; -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/