Added general info about the disk lock feature.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@3212 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 15 insertions, 0 deletions

diff --git a/www/lock.t b/www/lock.t
index e1dea45b8f..2b90082a56 100644
--- a/www/lock.t
+++ b/www/lock.t
@@ -47,4 +47,19 @@ that creates a linux boot disk with the below mentioned patched isd200 driver.
 <a href="mail/archive/rockbox-archive-2002-03/att-0010/01-isd200.diff">an isd200 driver patch for unlocking the disk</a>.
 This modified driver will automatically unlock the disk when you connect your Archos via USB, so you don't have to do anything special. Apply the patch to a 2.4.18 linux kernel tree.
 
+<h2>Still locked?</h2>
+
+<p>If the above suggestions don't work, here's some background info about the disk lock feature:
+
+<p>The disk lock is a built-in security feature in the disk. It is part of the ATA specification, and thus not specific to any brand or device.
+
+<p>A disk always has two passwords: A User password and a Master password. Most disks support a Master Password Revision Code, which can tell you if the Master password has been changed, or it it still the factory default. The revision code is word 92 in the IDENTIFY response. A value of 0xFFFE means the Master password is unchanged.
+
+<p>A disk can be locked in two modes: High security mode or Maximum security mode. Bit 8 in word 128 of the IDENTIFY response tell you which mode your disk is in: 0 = High, 1 = Maximum.
+
+<p>In High security mode, you can unlock the disk with either the user or master password, using the "SECURITY UNLOCK DEVICE" ATA command. There is an attempt limit, normally set to 5, after which you must power cycle or hard-reset the disk before you can attempt again.
+
+<p>In Maximum security mode, you <b>cannot</b> unlock the disk! The only way to get the disk back to a usable state is to issue the SECURITY ERASE PREPARE command, immediately followed by SECURITY ERASE UNIT. The SECURITY ERASE UNIT command requires the Master password and will completely erase all data on the disk. The operation is rather slow, expect half an hour or more for big disks. (Word 89 in the IDENTIFY response indicates how long the operation will take.)
+
+
 #include "foot.t"