91 lines
2.8 KiB
Plaintext
91 lines
2.8 KiB
Plaintext
|
C2 port support
|
||
|
|
---------------
|
||
|
|
|
||
|
|
(C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.com>
|
||
|
|
|
||
|
|
This program is free software; you can redistribute it and/or modify
|
||
|
|
it under the terms of the GNU General Public License as published by
|
||
|
|
the Free Software Foundation; either version 2 of the License, or
|
||
|
|
(at your option) any later version.
|
||
|
|
|
||
|
|
This program is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
GNU General Public License for more details.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Overview
|
||
|
|
--------
|
||
|
|
|
||
|
|
This driver implements the support for Linux of Silicon Labs (Silabs)
|
||
|
|
C2 Interface used for in-system programming of micro controllers.
|
||
|
|
|
||
|
|
By using this driver you can reprogram the in-system flash without EC2
|
||
|
|
or EC3 debug adapter. This solution is also useful in those systems
|
||
|
|
where the micro controller is connected via special GPIOs pins.
|
||
|
|
|
||
|
|
References
|
||
|
|
----------
|
||
|
|
|
||
|
|
The C2 Interface main references are at (http://www.silabs.com)
|
||
|
|
Silicon Laboratories site], see:
|
||
|
|
|
||
|
|
- AN127: FLASH Programming via the C2 Interface at
|
||
|
|
http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/Small_Form_Factor/en/an127.pdf, and
|
||
|
|
|
||
|
|
- C2 Specification at
|
||
|
|
http://www.silabs.com/public/documents/tpub_doc/spec/Microcontrollers/en/C2spec.pdf,
|
||
|
|
|
||
|
|
however it implements a two wire serial communication protocol (bit
|
||
|
|
banging) designed to enable in-system programming, debugging, and
|
||
|
|
boundary-scan testing on low pin-count Silicon Labs devices. Currently
|
||
|
|
this code supports only flash programming but extensions are easy to
|
||
|
|
add.
|
||
|
|
|
||
|
|
Using the driver
|
||
|
|
----------------
|
||
|
|
|
||
|
|
Once the driver is loaded you can use sysfs support to get C2port's
|
||
|
|
info or read/write in-system flash.
|
||
|
|
|
||
|
|
# ls /sys/class/c2port/c2port0/
|
||
|
|
access flash_block_size flash_erase rev_id
|
||
|
|
dev_id flash_blocks_num flash_size subsystem/
|
||
|
|
flash_access flash_data reset uevent
|
||
|
|
|
||
|
|
Initially the C2port access is disabled since you hardware may have
|
||
|
|
such lines multiplexed with other devices so, to get access to the
|
||
|
|
C2port, you need the command:
|
||
|
|
|
||
|
|
# echo 1 > /sys/class/c2port/c2port0/access
|
||
|
|
|
||
|
|
after that you should read the device ID and revision ID of the
|
||
|
|
connected micro controller:
|
||
|
|
|
||
|
|
# cat /sys/class/c2port/c2port0/dev_id
|
||
|
|
8
|
||
|
|
# cat /sys/class/c2port/c2port0/rev_id
|
||
|
|
1
|
||
|
|
|
||
|
|
However, for security reasons, the in-system flash access in not
|
||
|
|
enabled yet, to do so you need the command:
|
||
|
|
|
||
|
|
# echo 1 > /sys/class/c2port/c2port0/flash_access
|
||
|
|
|
||
|
|
After that you can read the whole flash:
|
||
|
|
|
||
|
|
# cat /sys/class/c2port/c2port0/flash_data > image
|
||
|
|
|
||
|
|
erase it:
|
||
|
|
|
||
|
|
# echo 1 > /sys/class/c2port/c2port0/flash_erase
|
||
|
|
|
||
|
|
and write it:
|
||
|
|
|
||
|
|
# cat image > /sys/class/c2port/c2port0/flash_data
|
||
|
|
|
||
|
|
after writing you have to reset the device to execute the new code:
|
||
|
|
|
||
|
|
# echo 1 > /sys/class/c2port/c2port0/reset
|