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Commit 7a4571ae authored by Michael Ellerman's avatar Michael Ellerman Committed by Paul Mackerras
Browse files

[POWERPC] Export flat device tree via debugfs for debugging 



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: default avatarMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 1dce0e30

arch/powerpc/kernel/prom.c

+25 −0
Original line number Diff line number Diff line
@@ -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>
@@ -2148,3 +2149,27 @@ struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) 
	}

	return NULL;

}



#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