DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=message-id:date:from:user-agent:mime-version:to:cc:subject
         :references:in-reply-to:content-type:content-transfer-encoding;
        b=Zx9RRbSDs8HfQuZ17MbQXECj6HpQKLImyL+9xIrheSZZRJFzmSObyRAHvThGPtdN2y
         LZmMKDecUbscySMYU+9qUYypNIbhomTKhmk2WBmZCGyoPty7ooixSYaHMf9+Qy38Uorw
         jj3m+Fovd/70viJhYPt83s4NOyPQbfCsemWdA=
Message-ID: <4CFD3371.3080807@gmail.com>
Date: Mon, 06 Dec 2010 11:03:13 -0800
From: Dirk Brandewie <dirk.brandewie@gmail.com>
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.12) Gecko/20101027 Fedora/3.1.6-1.fc13 Thunderbird/3.1.6
MIME-Version: 1.0
To: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
CC: linux-kernel@vger.kernel.org, Randy Dunlap <rdunlap@xenotime.net>,
        devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org,
        Grant Likely <grant.likely@secretlab.ca>
Subject: Re: [PATCH] of/fdt: add kernel command line option for dtb_compat
 string
References: <1291658059-383-1-git-send-email-dirk.brandewie@gmail.com> <4bb36a12-8d95-4d4e-936c-c1c74a9372cc@VA3EHSMHS025.ehs.local> <4CFD3322.1000503@gmail.com>
In-Reply-To: <4CFD3322.1000503@gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 3269
Lines: 113

On 12/06/2010 11:01 AM, Dirk Brandewie wrote:
> On 12/06/2010 10:37 AM, Stephen Neuendorffer wrote:
>>
>>
>>> 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<linux/of_fdt.h>
>>> #include<linux/string.h>
>>> #include<linux/errno.h>
>>> +#include<asm-generic/vmlinux.lds.h>
>>> +
>>>
>>> #ifdef CONFIG_PPC
>>> #include<asm/machdep.h>
>>> @@ -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?
>
> I would like to get rid of the pointer dance. Is your patch set going to make it
> into .37? I didn't see any acks.
>
Obviously I meant .38 :-)

>> It takes a blob argument. Then the loop below goes away.
>>
>
> The loop will still be needed since multiple DTBs may be linked into the image.
> using your of_fdt_is_compatible() will make the loop a lot more readable though.
>
> --Dirk
>
>> 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. 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.
>>
>>
>

--
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/