[PATCH] powerpc: Export flat device tree via debugfs for debugging

[PATCH] powerpc: Export flat device tree via debugfs for debugging

[Michael Ellerman]

If DEBUG is turned on in prom.c, export the flat device tree via debugfs.
This has been handy on several occasions.

To look at it:
 # mount -t debugfs none /sys/kernel/debug
 # od -a /sys/kernel/debug/powerpc/flat-device-tree
 and/or
 # dtc -fI dtb /sys/kernel/debug/powerpc/flat-device-tree -O dts

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---

 arch/powerpc/kernel/prom.c |   25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

Index: to-merge/arch/powerpc/kernel/prom.c
===================================================================
--- to-merge.orig/arch/powerpc/kernel/prom.c
+++ to-merge/arch/powerpc/kernel/prom.c
@@ -30,6 +30,7 @@
 #include <linux/bitops.h>
 #include <linux/module.h>
 #include <linux/kexec.h>
+#include <linux/debugfs.h>
 
 #include <asm/prom.h>
 #include <asm/rtas.h>
@@ -2009,3 +2010,27 @@ void kdump_move_device_tree(void)
 	/* XXX should we unreserve the old DT? */
 }
 #endif /* CONFIG_KEXEC */
+
+#ifdef DEBUG
+static struct debugfs_blob_wrapper flat_dt_blob;
+
+static int __init export_flat_device_tree(void)
+{
+	struct dentry *d;
+
+	d = debugfs_create_dir("powerpc", NULL);
+	if (!d)
+		return 1;
+
+	flat_dt_blob.data = initial_boot_params;
+	flat_dt_blob.size = initial_boot_params->totalsize;
+
+	d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
+				d, &flat_dt_blob);
+	if (!d)
+		return 1;
+
+	return 0;
+}
+__initcall(export_flat_device_tree);
+#endif

Re: [PATCH] powerpc: Export flat device tree via debugfs for debugging

[Kumar Gala]

On May 1, 2006, at 2:40 AM, Michael Ellerman wrote:

> If DEBUG is turned on in prom.c, export the flat device tree via  
> debugfs.
> This has been handy on several occasions.
>
> To look at it:
>  # mount -t debugfs none /sys/kernel/debug
>  # od -a /sys/kernel/debug/powerpc/flat-device-tree
>  and/or
>  # dtc -fI dtb /sys/kernel/debug/powerpc/flat-device-tree -O dts
>
> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
> ---
>
>  arch/powerpc/kernel/prom.c |   25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> Index: to-merge/arch/powerpc/kernel/prom.c
> ===================================================================
> --- to-merge.orig/arch/powerpc/kernel/prom.c
> +++ to-merge/arch/powerpc/kernel/prom.c
> @@ -30,6 +30,7 @@
>  #include <linux/bitops.h>
>  #include <linux/module.h>
>  #include <linux/kexec.h>
> +#include <linux/debugfs.h>
>
>  #include <asm/prom.h>
>  #include <asm/rtas.h>
> @@ -2009,3 +2010,27 @@ void kdump_move_device_tree(void)
>  	/* XXX should we unreserve the old DT? */
>  }
>  #endif /* CONFIG_KEXEC */
> +
> +#ifdef DEBUG

Shouldn't this also depend on DEBUGFS being built in.

> +static struct debugfs_blob_wrapper flat_dt_blob;
> +
> +static int __init export_flat_device_tree(void)
> +{
> +	struct dentry *d;
> +
> +	d = debugfs_create_dir("powerpc", NULL);
> +	if (!d)
> +		return 1;
> +
> +	flat_dt_blob.data = initial_boot_params;
> +	flat_dt_blob.size = initial_boot_params->totalsize;
> +
> +	d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
> +				d, &flat_dt_blob);
> +	if (!d)
> +		return 1;
> +
> +	return 0;
> +}
> +__initcall(export_flat_device_tree);
> +#endif
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev

Re: [PATCH] powerpc: Export flat device tree via debugfs for debugging

[Michael Ellerman]

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On Mon, 2006-05-01 at 12:54 -0500, Kumar Gala wrote:
> On May 1, 2006, at 2:40 AM, Michael Ellerman wrote:
> 
> > If DEBUG is turned on in prom.c, export the flat device tree via  
> > debugfs.
> > This has been handy on several occasions.
> >
> > To look at it:
> >  # mount -t debugfs none /sys/kernel/debug
> >  # od -a /sys/kernel/debug/powerpc/flat-device-tree
> >  and/or
> >  # dtc -fI dtb /sys/kernel/debug/powerpc/flat-device-tree -O dts
> >
> > Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
> > ---
> >
> >  arch/powerpc/kernel/prom.c |   25 +++++++++++++++++++++++++
> >  1 file changed, 25 insertions(+)
> >
> > Index: to-merge/arch/powerpc/kernel/prom.c
> > ===================================================================
> > --- to-merge.orig/arch/powerpc/kernel/prom.c
> > +++ to-merge/arch/powerpc/kernel/prom.c
> > @@ -30,6 +30,7 @@
> >  #include <linux/bitops.h>
> >  #include <linux/module.h>
> >  #include <linux/kexec.h>
> > +#include <linux/debugfs.h>
> >
> >  #include <asm/prom.h>
> >  #include <asm/rtas.h>
> > @@ -2009,3 +2010,27 @@ void kdump_move_device_tree(void)
> >  	/* XXX should we unreserve the old DT? */
> >  }
> >  #endif /* CONFIG_KEXEC */
> > +
> > +#ifdef DEBUG
> 
> Shouldn't this also depend on DEBUGFS being built in.

It could, but DEBUG_FS is written so that you don't have to care, so I
didn't :)

cheers

-- 
Michael Ellerman
IBM OzLabs

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person

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Re: [PATCH] powerpc: Export flat device tree via debugfs for debugging

[Kumar Gala]

On May 1, 2006, at 7:20 PM, Michael Ellerman wrote:

> On Mon, 2006-05-01 at 12:54 -0500, Kumar Gala wrote:
>> On May 1, 2006, at 2:40 AM, Michael Ellerman wrote:
>>
>>> If DEBUG is turned on in prom.c, export the flat device tree via
>>> debugfs.
>>> This has been handy on several occasions.
>>>
>>> To look at it:
>>>  # mount -t debugfs none /sys/kernel/debug
>>>  # od -a /sys/kernel/debug/powerpc/flat-device-tree
>>>  and/or
>>>  # dtc -fI dtb /sys/kernel/debug/powerpc/flat-device-tree -O dts
>>>
>>> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
>>> ---
>>>
>>>  arch/powerpc/kernel/prom.c |   25 +++++++++++++++++++++++++
>>>  1 file changed, 25 insertions(+)
>>>
>>> Index: to-merge/arch/powerpc/kernel/prom.c
>>> ===================================================================
>>> --- to-merge.orig/arch/powerpc/kernel/prom.c
>>> +++ to-merge/arch/powerpc/kernel/prom.c
>>> @@ -30,6 +30,7 @@
>>>  #include <linux/bitops.h>
>>>  #include <linux/module.h>
>>>  #include <linux/kexec.h>
>>> +#include <linux/debugfs.h>
>>>
>>>  #include <asm/prom.h>
>>>  #include <asm/rtas.h>
>>> @@ -2009,3 +2010,27 @@ void kdump_move_device_tree(void)
>>>  	/* XXX should we unreserve the old DT? */
>>>  }
>>>  #endif /* CONFIG_KEXEC */
>>> +
>>> +#ifdef DEBUG
>>
>> Shouldn't this also depend on DEBUGFS being built in.
>
> It could, but DEBUG_FS is written so that you don't have to care, so I
> didn't :)

Cool.  Haven't messed with DEBUG_FS.

- k