[PATCH] of/fdt: add kernel command line option for dtb_compat string

[PATCH] of/fdt: add kernel command line option for dtb_compat string

[dirk.brandewie]

From: Dirk Brandewie <dirk.brandewie@gmail.com>

Adds a kernel command line option "dtb_compat=<string>".  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 <dirk.brandewie@gmail.com>
---
 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 <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;
+
+	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

RE: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Stephen Neuendorffer]

> -----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 <dirk.brandewie@gmail.com>
> 
> Adds a kernel command line option "dtb_compat=<string>".  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 <dirk.brandewie@gmail.com>
> ---
>  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 <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?
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


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Re: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Dirk Brandewie]

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.

> 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.
>
>

Re: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Dirk Brandewie]

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.
>>
>>
>

RE: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Stephen Neuendorffer]

> -----Original Message-----
> From: Dirk Brandewie [mailto:dirk.brandewie@gmail.com]
> Sent: Monday, December 06, 2010 11:03 AM
> To: Stephen Neuendorffer
> Cc: linux-kernel@vger.kernel.org; Randy Dunlap;
devicetree-discuss@lists.ozlabs.org; linux-
> doc@vger.kernel.org; grant.likely@secretlab.ca
> Subject: Re: [PATCH] of/fdt: add kernel command line option for
dtb_compat string
> 
> 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 :-)

I'd like it too, but that's up to Grant.  I imagine some of the
bottleneck is that I don't have
an easy way to test on powerpc or microblaze at the moment, so it's not
clear that the code doesn't
break anything.

> >> 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.

Yeah, right.  Is the format just the binary concatenation of the device
trees?  part of why I ask
is the PTR_ALIGN code: It seems like different blob functions make
different assumptions about the 
location of the blob. In some cases, it is assumed to be the passed
pointer, in others, 
the pointer is scanned for OF_DT_BEGIN_NODE (using of_get_flat_dt_root).
Is the concern about
STRUCT_ALIGNMENT necessary if you call of_get_flat_dt_root() afterwards?
Would it make sense to
always call of_get_flat_dt_root in the 'generic' functions I added or
not?

BTW, PTR_ALIGN should probably be ALIGN.

Steve

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Re: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Dirk Brandewie]

On 12/06/2010 01:50 PM, Stephen Neuendorffer wrote:
>
>
>> -----Original Message-----
>> From: Dirk Brandewie [mailto:dirk.brandewie@gmail.com]
>> Sent: Monday, December 06, 2010 11:03 AM
>> To: Stephen Neuendorffer
>> Cc: linux-kernel@vger.kernel.org; Randy Dunlap;
> devicetree-discuss@lists.ozlabs.org; linux-
>> doc@vger.kernel.org; grant.likely@secretlab.ca
>> Subject: Re: [PATCH] of/fdt: add kernel command line option for
> dtb_compat string
>>
>> 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 :-)
>
> I'd like it too, but that's up to Grant.  I imagine some of the
> bottleneck is that I don't have
> an easy way to test on powerpc or microblaze at the moment, so it's not
> clear that the code doesn't
> break anything.
>
>>>> 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.
>
> Yeah, right.  Is the format just the binary concatenation of the device
> trees?

No each blob starts on a STRUCT_ALIGNMENT boundary.  If the blob does not have 
the correct alignment the code that GCC generates to reference into the 
structure breaks.

part of why I ask
> is the PTR_ALIGN code: It seems like different blob functions make
> different assumptions about the
> location of the blob. In some cases, it is assumed to be the passed
> pointer, in others,
> the pointer is scanned for OF_DT_BEGIN_NODE (using of_get_flat_dt_root).
> Is the concern about
> STRUCT_ALIGNMENT necessary if you call of_get_flat_dt_root() afterwards?
> Would it make sense to
> always call of_get_flat_dt_root in the 'generic' functions I added or
> not?
The padding between blobs is added in the assembly wrapper (zero fill) 
of_get_flat_dt_root() assumes the blob pointer (initial_boot_params) is the head 
of the blob and only skips OF_DT_NOP (0x4).  If we always hand in the pointer to 
the head of the blob the rest of fdt.c should be happy with it.

>
> BTW, PTR_ALIGN should probably be ALIGN.
Originally I used ALIGN but needed to cast the result of ALIGN blob to get rid 
of a compiler warning Grant suggested PTR_ALIGN which does the cast for you.

>
> Steve
>
> 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.
>
>

Re: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Dirk Brandewie]

On 12/06/2010 01:50 PM, Stephen Neuendorffer wrote:
>
>
>> -----Original Message-----
>> From: Dirk Brandewie [mailto:dirk.brandewie@gmail.com]
>> Sent: Monday, December 06, 2010 11:03 AM
>> To: Stephen Neuendorffer
>> Cc: linux-kernel@vger.kernel.org; Randy Dunlap;
> devicetree-discuss@lists.ozlabs.org; linux-
>> doc@vger.kernel.org; grant.likely@secretlab.ca
>> Subject: Re: [PATCH] of/fdt: add kernel command line option for
> dtb_compat string
>>
>> 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 :-)
>
> I'd like it too, but that's up to Grant.

Grant any guidance here?

I imagine some of the
> bottleneck is that I don't have
> an easy way to test on powerpc or microblaze at the moment, so it's not
> clear that the code doesn't
> break anything.
>

Re: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Dirk Brandewie]

On 12/06/2010 09:54 AM, dirk.brandewie@gmail.com wrote:
> From: Dirk Brandewie<dirk.brandewie@gmail.com>
>
> Adds a kernel command line option "dtb_compat=<string>".  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<dirk.brandewie@gmail.com>
> ---
>   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<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;
> +
> +	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);
> +

Any other comments on this patch?  Do I need to port it to use Stephens patch 
set to allow passing in blobs to fdt.c?

--Dirk

Re: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Dirk Brandewie]

On 12/06/2010 09:54 AM, dirk.brandewie@gmail.com wrote:
> From: Dirk Brandewie<dirk.brandewie@gmail.com>
>
> Adds a kernel command line option "dtb_compat=<string>".  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<dirk.brandewie@gmail.com>
> ---
>   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<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;
> +
> +	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);
> +
Any more comments on this patch? Is it good to go or DOA?

Thanks
--Dirk

Re: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Grant Likely]

On Mon, Dec 06, 2010 at 01:50:47PM -0800, Stephen Neuendorffer wrote:
> 
> 
> > -----Original Message-----
> > From: Dirk Brandewie [mailto:dirk.brandewie@gmail.com]
> > Sent: Monday, December 06, 2010 11:03 AM
> > To: Stephen Neuendorffer
> > Cc: linux-kernel@vger.kernel.org; Randy Dunlap;
> devicetree-discuss@lists.ozlabs.org; linux-
> > doc@vger.kernel.org; grant.likely@secretlab.ca
> > Subject: Re: [PATCH] of/fdt: add kernel command line option for
> dtb_compat string
> > 
> > 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 :-)
> 
> I'd like it too, but that's up to Grant.  I imagine some of the
> bottleneck is that I don't have
> an easy way to test on powerpc or microblaze at the moment, so it's not
> clear that the code doesn't
> break anything.

It's in my -next branch now.

g.

Re: [PATCH] of/fdt: add kernel command line option for dtb_compat string

[Grant Likely]

On Wed, Dec 22, 2010 at 12:04:56PM -0800, Dirk Brandewie wrote:
> On 12/06/2010 09:54 AM, dirk.brandewie@gmail.com wrote:
> >From: Dirk Brandewie<dirk.brandewie@gmail.com>
> >
> >Adds a kernel command line option "dtb_compat=<string>".  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<dirk.brandewie@gmail.com>
> >---
> >  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<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;
> >+
> >+	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);
> >+
> Any more comments on this patch? Is it good to go or DOA?

Not DOA, but I want to discuss the linking vs. wrapper issue again
before I commit to merging it.  BTW, sorry for being MIA on this stuff
for pretty much all December.  I got over committed, but things should
be better now.

g.