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Implement the meat of FLIP version 1 protocol, and document it.

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git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@1269 81a1dc3b-b13d-400b-aceb-764788c761c2
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joerg_wunsch
2014-01-17 16:54:33 +00:00
parent 774c46b860
commit b6fd404109
5 changed files with 436 additions and 287 deletions
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35
doc/avrdude.texi
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@@ -244,7 +244,9 @@ has been compiled with libusb support.
They both feature simple firmware-only USB implementations, running on
an ATmega8 (or ATmega88), or ATtiny2313, respectively.
The Atmel DFU bootloader is supported in version 2 (Xmega devices).
The Atmel DFU bootloader is supported in both, FLIP protocol version 1
(AT90USB* and ATmega*U* devices), as well as version 2 (Xmega devices).
See below for some hints about FLIP version 1 protocol behaviour.
@menu
@@ -1658,12 +1660,13 @@ functionality does not make sense for these boot loaders.
@menu
* Atmel STK600::
* Atmel DFU bootloader using FLIP version 1::
@end menu
@c
@c Node
@c
@node Atmel STK600, , Programmer Specific Information, Programmer Specific Information
@node Atmel STK600, Atmel DFU bootloader using FLIP version 1, Programmer Specific Information, Programmer Specific Information
@section Atmel STK600
@c
@@ -1756,6 +1759,34 @@ High-voltage programming requires the target voltage to be set to at
least 4.5 V in order to work. This can be done using
@emph{Terminal Mode}, see @ref{Terminal Mode Operation}.
@c
@c Node
@c
@node Atmel DFU bootloader using FLIP version 1, , Atmel STK600, Programmer Specific Information
@section Atmel DFU bootloader using FLIP version 1
Bootloaders using the FLIP protocol version 1 experience some very
specific behaviour.
These bootloaders have no option to access memory areas other than
Flash and EEPROM.
When the bootloader is started, it enters a @emph{security mode} where
the only acceptable access is to query the device configuration
parameters (which are used for the signature on AVR devices). The
only way to leave this mode is a @emph{chip erase}. As a chip erase
is normally implied by the @option{-U} option when reprogramming the
flash, this peculiarity might not be very obvious immediately.
Sometimes, a bootloader with security mode already disabled seems to
no longer respond with sensible configuration data, but only 0xFF for
all queries. As these queries are used to obtain the equivalent of a
signature, AVRDUDE can only continue in that situation by forcing the
signature check to be overridden with the @option{-F} option.
A @emph{chip erase} might leave the EEPROM unerased, at least on some
versions of the bootloader.
@c
@c Node
@c