diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index e97c32c..d5ea36c 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -763,6 +763,34 @@ static loff_t memory_lseek(struct file *
 	return ret;
 }
 
+static loff_t seek_pi(struct file * file, loff_t offset, int orig)
+{
+	return -EINVAL;
+}
+
+static ssize_t write_pi(struct file * file, const char __user * buf,
+			  size_t count, loff_t *ppos)
+{
+	return -EPERM;
+}
+
+static ssize_t read_pi(struct file * file, char __user * buf, 
+			 size_t count, loff_t *ppos)
+{
+	int ok = 0;
+	
+	if (!count)
+		return 0;
+
+	if (!access_ok(VERIFY_WRITE, buf, count))
+		return -EFAULT;
+
+	if (*ppos == 0) { buf[0] = '3'; ok = 1; }
+	*ppos = 1;
+
+	return ok;
+}
+
 static int open_port(struct inode * inode, struct file * filp)
 {
 	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
@@ -825,6 +853,12 @@ static const struct file_operations full
 	.write		= write_full,
 };
 
+static const struct file_operations pi_fops = {
+	.llseek		= /*memory_lseek*/ seek_pi,
+	.read		= read_pi,
+	.write		= /*write_full*/ write_pi,
+};
+
 #ifdef CONFIG_CRASH_DUMP
 static const struct file_operations oldmem_fops = {
 	.read	= read_oldmem,
@@ -895,6 +929,9 @@ #ifdef CONFIG_CRASH_DUMP
 			filp->f_op = &oldmem_fops;
 			break;
 #endif
+		case 255:
+			filp->f_op = &pi_fops;
+			break;
 		default:
 			return -ENXIO;
 	}
@@ -927,6 +964,7 @@ #endif
 #ifdef CONFIG_CRASH_DUMP
 	{12,"oldmem",    S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
 #endif
+	{255,"pi",    S_IRUGO, &pi_fops},
 };
 
 static struct class *mem_class;