c5c4db0196
This commits adds a new error code that can be return from a registered control callback: USBD_REQ_NEXT_CALLBACK. This return code signifies that the callback is done processing the data successfully, but user would like to have all matching callbacks down the callback chain to be executed too. This change allows for example to intercept standard requests like GET_DESCRIPTOR, do some small action upon receiving of one, but still have the standard callback executed and do it's job. This way user doesn't have to re-implement standard GET_DESCRIPTOR functionality if they want to intercept that request to do some small thing.
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README
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The libopencm3 project aims to create an open-source firmware library for
various ARM Cortex-M3 microcontrollers.
Currently (at least partly) supported microcontrollers:
- ST STM32F1 series
- ST STM32F2 series
- ST STM32F4 series
- NXP LPC1311/13/42/43
The library is written completely from scratch based on the vendor datasheets,
programming manuals, and application notes. The code is meant to be used
with a GCC toolchain for ARM (arm-elf or arm-none-eabi), flashing of the
code to a microcontroller can be done using the OpenOCD ARM JTAG software.
Status and API
--------------
The libopencm3 project is currently work in progress. Not all subsystems
of the microcontrollers are supported, yet.
IMPORTANT: The API of the library is NOT yet considered stable! Please do
not rely on it, yet! Changes to function names, macro names etc.
can happen at any time without prior notice!
Building
--------
$ make
You may want to override the toolchain (e.g., arm-elf or arm-none-eabi):
$ PREFIX=arm-none-eabi make
For a more verbose build you can use
$ make V=1
Example projects
----------------
The library ships with a few small example projects which illustrate how
individual subsystems of the microcontrollers can be configured and used with
libopencm3.
For flashing the 'miniblink' example (after you built libopencm3 and the
examples by typing 'make' at the top-level directory) onto the Olimex
STM32-H103 eval board (ST STM32F1 series microcontroller), you can execute:
$ cd examples/stm32/f1/stm32-h103/miniblink
$ make flash
The Makefiles of the examples are configured to use a certain OpenOCD
flash programmer, you might need to change some of the variables in the
Makefile if you use a different one.
You can also flash manually like this:
$ openocd -f interface/jtagkey-tiny.cfg -f target/stm32f1x.cfg
$ telnet localhost 4444
> reset halt
> flash write_image erase foobar.hex
> reset
Replace the "jtagkey-tiny.cfg" with whatever JTAG device you are using, and/or
replace "stm32f1x.cfg" with your respective config file. Replace "foobar.hex"
with the file name of the image you want to flash.
Installation
------------
$ make install
This will install the library in /usr/local. If you want to install it
elsewhere, use the following syntax:
$ DESTDIR=/opt make install
The recommended location is to install into your toolchain directory, e.g.
/home/someuser/sat for a toolchain built using the summon-arm-toolchain
script from https://github.com/esden/summon-arm-toolchain.
$ DESTDIR=~/sat make install
Coding style and development guidelines
---------------------------------------
See HACKING.
License
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The libopencm3 code is released under the terms of the GNU Lesser General
Public License (LGPL), version 3 or later.
See COPYING.GPL3 and COPYING.LGPL3 for details.
Mailing lists
-------------
* Developer mailing list (for patches and discussions):
https://lists.sourceforge.net/lists/listinfo/libopencm3-devel
* Commits mailing list (receives one mail per 'git push'):
https://lists.sourceforge.net/lists/listinfo/libopencm3-commits
Website
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http://libopencm3.org
http://sourceforge.net/projects/libopencm3/