2184eb2b13
Modify lm4f_ep_read/write_packet() to take advantage of 32-bit and 16-bit accesses to the USB FIFO, as opposed to using only 8-bit accesses. This change increases endpoint performance in a number of configurations. On the host side, we use usb_bulk_bench to test https://github.com/mrnuke/usb_bulk_bench With the following invocations: usb_bulk_bench -d c03e:b007 -a -t 64 -q 32 -e [ep] [-I/-O] On the device side, we use the usb_bulk_dev example: https://github.com/mrnuke/libopencm3-examples/tree/stellaris The example is in: examples/lm4f/stellaris-ek-lm4f120xl/usb_bulk_dev (This example will be available in libopencm3-examples in the near future) The endpoints configuration is the following: * EP1 OUT - interrupt driven RX endpoint * EP2 IN - interrupt driven TX endpoint * EP3 OUT - polled RX endpoint * EP4 IN - polled TX endpoint * EP5 OUT - polled RX endpoint with unaligned buffer * EP6 IN - polled TX endpoint with unaligned buffer We test the speed in each configuration, using different system clock frequencies. We run the tests once without the patch applied, and once with the patch applied. The results are given below: Before patch (numbers in KiB/s): freq: 80 MHz 57 MHz 40 MHz 30 MHz 20 MHz 16 MHz EP1 562 562 562 562 562 550 EP2 936 872 812 812 687 625 EP3 1062 890 700 600 562 562 EP4 900 812 812 750 625 562 EP5 1062 890 700 600 562 562 EP6 930 812 812 750 625 562 With patch (numbers in KiB/s): freq: 80 MHz 57 MHz 40 MHz 30 MHz 20 MHz 16 MHz EP1 1062 1062 1062 690 562 562 EP2 1125 936 936 936 870 812 EP3 1062 960 750 750 562 562 EP4 936 936 870 870 770 700 EP5 1062 900 700 630 562 562 EP6 930 930 870 870 740 650 Percent change in speed (*): freq: 80 MHz 57 MHz 40 MHz 30 MHz 20 MHz 16 MHz EP1 89.0 89.0 89.0 22.8 0.0 2.2 EP2 20.2 7.3 15.3 15.3 26.6 29.9 EP3 0.0 7.9 7.1 25.0 0.0 0.0 EP4 4.0 15.3 7.1 16.0 23.2 24.6 EP5 0.0 1.1 0.0 5.0 0.0 0.0 EP6 0.0 14.5 7.1 16.0 18.4 15.7 (*) Numbers given as percent change relative to speed before applying this patch. We see throughput increases across the board. Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
------------------------------------------------------------------------------
README
------------------------------------------------------------------------------
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!
Prerequisites
-------------
Building requires python, and a python YAML module. (Some code is generated)
For Ubuntu
$ [sudo] apt-get install python-yaml
For Fedora
$ [sudo] yum install PyYAML
For Windows
Download and install:
msys - sourceforge.net/projects/mingw/files/MSYS/Base/msys-core/msys-1.0.11/MSYS-1.0.11.exe
Python - http://www.python.org/ftp/python/2.7/python-2.7.msi (use installer to get the right registry keys for PyYAML)
PyYAML - http://pyyaml.org/download/pyyaml/PyYAML-3.10.win32-py2.7.exe
arm-none-eabi toolchain - for example this one https://launchpad.net/gcc-arm-embedded
Run msys shell and set the path without standard Windows paths, so Windows programs such as 'find' won't interfere:
export PATH="/c//Python27:/c/ARMToolchain/bin:/usr/local/bin:/usr/bin:/bin"
After that you can navigate to the folder where you've extracted libopencm3 and build it.
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 libopencm3 community has written and is maintaining a huge collection of
examples, displaying the capabilities and uses of the library. You can find all
of them in the libopencm3-examples repository:
https://github.com/libopencm3/libopencm3-examples
Installation
------------
$ make install
This will install the library into /usr/local. (permissions permitting)
If you want to install it elsewhere, use the following syntax:
$ make DESTDIR=/opt/libopencm3 install
If you want to attempt to install into your toolchain, use this:
$ make DETECT_TOOLCHAIN=1 install
Note: If you install this into your toolchain, you don't need to pass
any extra -L or -I flags into your projects. However, this also means
you must NOT pass any -L or -I flags that point into the toolchain. This
_will_ confuse the linker. (ie, for summon-arm-toolchain, do NOT pass
-L/home/user/sat/lib) Common symptoms of confusing
the linker are hard faults caused by branches into arm code.
You can use objdump to check for this in your final elf.
Coding style and development guidelines
---------------------------------------
See HACKING.
License
-------
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
-------
http://libopencm3.org
http://sourceforge.net/projects/libopencm3/