[POWERPC] Export flat device tree via debugfs for debugging
authorMichael Ellerman <michael@ellerman.id.au>
Fri, 23 Jun 2006 08:16:03 +0000 (18:16 +1000)
committerPaul Mackerras <paulus@samba.org>
Wed, 28 Jun 2006 01:59:46 +0000 (11:59 +1000)
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>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/kernel/prom.c

index 483455c5bb02e5ab00ae04ce6a138168e7f8075b..efed4bc2b454573977e53c03d3a91e7e347c1619 100644 (file)
@@ -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