Changeset 1493 for trunk/flashrom.8

Timestamp:

Feb 16, 2012 12:40:23 AM (16 months ago)

Author:

stefanct

Message:

Warn of one-time programmable (OTP) memory

Some flash chips contain OTP memory that we cannot read or write (yet). This
prohibits us from cloning them, hence warn the user if we detect it. Not all
variations of the tagged chips contain OTP memory. They are often only
enabled on request or have there own ordering numbers. There is usually no
way to distinguish them. Because this is a supposedly seldomly used feature
the warning is shown in with dbg verbosity.

The manpage is extended to describe the backgrounds a bit.

This patch is based on the idea and code of Daniel Lenski.
Signed-off-by: Daniel Lenski <dlenski@…>
Signed-off-by: Stefan Tauner <stefan.tauner@…>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@…>

File:

• trunk/flashrom.8 (modified) (1 diff)

trunk/flashrom.8

@@ -671 +671 @@
 .sp
 .B "  http://www.flashrom.org/Laptops"
+.SS
+One-time programmable (OTP) memory and unique IDs
+.sp
+Some flash chips contain OTP memory often denoted as "security registers".
+They usually have a capacity in the range of some bytes to a few hundred
+bytes and can be used to give devices unique IDs etc. flashrom is not able
+to read or write these memories and may therefore not be able to duplicate a
+chip completely. For chip types known to include OTP memories a warning is
+printed when they are detected.
+.sp
+Similar to OTP memories are unique, factory programmed, unforgeable IDs.
+They are not modifiable by the user at all.
+.RE
 .SH LICENSE
 .B flashrom