Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753243Ab0LFShW (ORCPT ); Mon, 6 Dec 2010 13:37:22 -0500 Received: from va3ehsobe010.messaging.microsoft.com ([216.32.180.30]:52765 "EHLO VA3EHSOBE010.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750837Ab0LFShU convert rfc822-to-8bit (ORCPT ); Mon, 6 Dec 2010 13:37:20 -0500 X-SpamScore: -20 X-BigFish: VPS-20(zz542N1432N9371Pzz1202hzz8275bh8275dhz2dh95h668h61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: KIP:(null);UIP:(null);IPVD:NLI;H:xsj-gw1;RD:unknown-60-83.xilinx.com;EFVD:NLI X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-Class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: [PATCH] of/fdt: add kernel command line option for dtb_compat string Date: Mon, 6 Dec 2010 10:37:14 -0800 In-Reply-To: <1291658059-383-1-git-send-email-dirk.brandewie@gmail.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [PATCH] of/fdt: add kernel command line option for dtb_compat string Thread-Index: AcuVbqzSh7jpLRWkQiCZurn6lEdwmAABdlRQ References: <1291658059-383-1-git-send-email-dirk.brandewie@gmail.com> From: Stephen Neuendorffer To: , CC: Randy Dunlap , , X-OriginalArrivalTime: 06 Dec 2010 18:37:12.0417 (UTC) FILETIME=[98E65D10:01CB9574] Message-ID: <4bb36a12-8d95-4d4e-936c-c1c74a9372cc@VA3EHSMHS025.ehs.local> X-OriginatorOrg: xilinx.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4488 Lines: 142 > -----Original Message----- > From: devicetree-discuss-bounces+stephen.neuendorffer=xilinx.com@lists.ozlabs. org [mailto:devicetree- > discuss-bounces+stephen.neuendorffer=xilinx.com@lists.ozlabs.org] On Behalf Of > dirk.brandewie@gmail.com > Sent: Monday, December 06, 2010 9:54 AM > To: linux-kernel@vger.kernel.org > Cc: Randy Dunlap; devicetree-discuss@lists.ozlabs.org; linux-doc@vger.kernel.org > Subject: [PATCH] of/fdt: add kernel command line option for dtb_compat string > > From: Dirk Brandewie > > Adds a kernel command line option "dtb_compat=". This string > will be used to select the first compatible device tree blob linked > into the kernel if a device tree blob is was *not* passed in by the > bootloader. > > Signed-off-by: Dirk Brandewie > --- > Documentation/kernel-parameters.txt | 8 ++++++ > drivers/of/fdt.c | 48 +++++++++++++++++++++++++++++++++++ > 2 files changed, 56 insertions(+), 0 deletions(-) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 92e83e5..64093e5 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -655,6 +655,14 @@ and is between 256 and 4096 characters. It is defined in the file > > dscc4.setup= [NET] > > + dtb_compat= [KNL] > + Specify the "compatible" string for the device > + tree blob present in the vmlinux image. This > + string will be used to select the first device > + tree blob whose compatible property matches > + the string if a dtb was NOT passed in by the > + bootloader. > + > dynamic_printk Enables pr_debug()/dev_dbg() calls if > CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. > These can also be switched on/off via > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index c1360e0..ca1318c 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -15,6 +15,8 @@ > #include > #include > #include > +#include > + > > #ifdef CONFIG_PPC > #include > @@ -604,3 +606,49 @@ void __init unflatten_device_tree(void) > > pr_debug(" <- unflatten_device_tree()\n"); > } > + > +extern uint8_t __dtb_start[]; > +extern uint8_t __dtb_end[]; > +static void __init *of_flat_dt_find_compatible_dtb(char *name) > +{ > + void *rc = NULL; > + unsigned long root, size; > + struct boot_param_header *orig_initial_boot_params; > + uint8_t *blob; > + > + orig_initial_boot_params = initial_boot_params; > + blob = __dtb_start; > + initial_boot_params = (struct boot_param_header *)blob; Oy... can you avoid the pointer dance by using of_fdt_is_compatible() from my recent set of patches? It takes a blob argument. Then the loop below goes away. Steve > + > + > + while (blob < __dtb_end) { > + if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) { > + WARN(1, "Invalid device tree blob in vmlinux\n"); > + break; > + } > + > + root = of_get_flat_dt_root(); > + if (of_flat_dt_is_compatible(root, name) > 0) { > + rc = blob; > + break; > + } > + > + size = be32_to_cpu(initial_boot_params->totalsize); > + blob = PTR_ALIGN(blob + size, STRUCT_ALIGNMENT); > + initial_boot_params = (struct boot_param_header *)blob; > + } > + > + if (rc == NULL) > + initial_boot_params = orig_initial_boot_params; > + return rc; > +} > + > + > +static int __init of_flat_dtb_compat_setup(char *line) > +{ > + if (!initial_boot_params) > + initial_boot_params = of_flat_dt_find_compatible_dtb(line); > + return 1; > +} > + > +early_param("dtb_compat", of_flat_dtb_compat_setup); > + > -- > 1.7.2.3 > > _______________________________________________ > devicetree-discuss mailing list > devicetree-discuss@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/devicetree-discuss 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. 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