Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757374Ab0KPWmV (ORCPT ); Tue, 16 Nov 2010 17:42:21 -0500 Received: from mail-iw0-f174.google.com ([209.85.214.174]:38110 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757009Ab0KPWmS (ORCPT ); Tue, 16 Nov 2010 17:42:18 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=ZSHwhCJcJ56IVPcSI+30X/wEIc4KkAPeR7L50WILAeyYdymrHGs31zAE4X9MUWlYYU gC8hjarJLduhqg5W6fASAfxZl1XgkWYVkjrIVh//BDWXmkVPMmhwxqp71DEB9McvFgQi XPqOXsFHBFriYhbwVB3vLOHJdHYpTL2dzFByE= From: dirk.brandewie@gmail.com To: devicetree-discuss@lists.ozlabs.org Cc: sodaville@linutronix.de, arjan@linux.intel.com, dirk.brandewie@gmail.com, linuxppc-dev@lists.ozlabs.org, microblaze-uclinux@itee.uq.edu.au, linux-arch@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/5] of/fdt: add kernel command line option for dtb_compat string Date: Tue, 16 Nov 2010 14:41:37 -0800 Message-Id: <348d48851a244bbd60bbfc4d60bee330e5c91eae.1289943240.git.dirk.brandewie@gmail.com> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4300 Lines: 135 From: Dirk Brandewie Adds a kernel command line option "dtb_compat=" and functions for architecture/platform specific code to retrieve the command line string and locate the compatible DTB linked into the kernel of_flat_dt_get_dtb_compatible_string() returns a pointer string passed from the command line or a pointer to an empty string. of_flat_dt_find_compatible_dtb() returns a pointer to a DTB that is compatible with the "compatible" string or a NULL pointer if no matching DTB is present. Signed-off-by: Dirk Brandewie --- Documentation/kernel-parameters.txt | 7 +++++ drivers/of/fdt.c | 52 +++++++++++++++++++++++++++++++++++ include/linux/of_fdt.h | 4 +++ 3 files changed, 63 insertions(+), 0 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ed45e98..f9b77fa 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -655,6 +655,13 @@ 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 kernel image. This + string will be used to select the first device + tree blob whose compatible property matches + the string passed on the kernel commandline. + 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..c0858ce 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 +606,53 @@ void __init unflatten_device_tree(void) pr_debug(" <- unflatten_device_tree()\n"); } + +#define MAX_DTB_COMPAT_STR 64 +char dtb_compat_name[MAX_DTB_COMPAT_STR] = ""; + +char __init *of_flat_dt_get_dtb_compatible_string(void) +{ + return dtb_compat_name; +} + + +extern uint8_t __dtb_start[]; +extern uint8_t __dtb_end[]; +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; + + while (blob < __dtb_end && + (be32_to_cpu(initial_boot_params->magic) == OF_DT_HEADER)) { + 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, DTB_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) +{ + strncpy(dtb_compat_name, line, MAX_DTB_COMPAT_STR); + return 1; +} + +early_param("dtb_compat", of_flat_dtb_compat_setup); + diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 7bbf5b3..29561f4 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -58,6 +58,7 @@ struct boot_param_header { }; #if defined(CONFIG_OF_FLATTREE) + /* TBD: Temporary export of fdt globals - remove when code fully merged */ extern int __initdata dt_root_addr_cells; extern int __initdata dt_root_size_cells; @@ -82,6 +83,9 @@ extern void early_init_dt_add_memory_arch(u64 base, u64 size); extern u64 early_init_dt_alloc_memory_arch(u64 size, u64 align); extern u64 dt_mem_next_cell(int s, __be32 **cellp); +extern char *of_flat_dt_get_dtb_compatible_string(void); +extern void *of_flat_dt_find_compatible_dtb(char *name); + /* * If BLK_DEV_INITRD, the fdt early init code will call this function, * to be provided by the arch code. start and end are specified as -- 1.7.2.3 -- 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/