This is a C project for ARM Cortex M0+, M0, M3 and M4 LPC microcontrollers. The GNU Toolchain is used for compilation, but the LPCXpresso IDE is still required for downloading and debugging via NXP's LPC-Link.

The master branch is not intended to be built - Rather it is just a base that implementations for particular chips can be derived from.

To switch to a branch that will do something useful:

• On GitHub: Select a branch from the drop-down menu above.
• On the command line: git branch to see a list of branches and switch to one with git checkout <branch>.

Prerequisites

GNU Make and the following standard utilities are required: cat, echo, find, grep, mkdir, rm, sed and shuf. If you're running any sensible desktop linux then these will already be installed.

You will need to aquire GNU Tools for ARM Embedded Processors.

On Ubuntu

sudo add-apt-repository ppa:terry.guo/gcc-arm-embedded
sudo apt-get update && sudo apt-get install gcc-arm-none-eabi

Note about gcc-arm-embedded on Ubuntu 14.04 and later

If you are using Ubuntu 14.04 and later, please be careful because there are packages with same name but produced by Debian and inherited by Ubuntu. Simply follow the above 3 steps, you may end up with gcc-arm-none-eabi from Ubuntu. So to install gcc-arm-none-eabi from ARM, steps are:

1). sudo apt-get remove binutils-arm-none-eabi gcc-arm-none-eabi
2). sudo add-apt-repository ppa:terry.guo/gcc-arm-embedded
3). sudo apt-get update
4). sudo apt-get install gcc-arm-none-eabi=4-8-2014q2-0trusty10

Meanwhile we are working with Debian to consolidate and unify this toolchain.

Otherwise

Download and add the bin/ directory to your path. If you use [Bash](https://en.wikipedia.org/wiki/Bash_(Unix_shell\)), you might be able to do this by adding export PATH=$PATH:/path/to/gnu/tools/for/arm/bin/ to your ~/.bashrc.

Not Recommended

You could build your own tools from source. Have a look at summon-arm-toolchain.

Configuration

Most of the configuration options related to the chip are located in makefile.conf. Please read the file itself for full details on each of the options. You should probably run make clean after editing makefile.conf.

The sizes and locations of your chip's memory locations should be defined in mem.ld. Any other changes to the layout of the final binary (such as using external/AHB RAM or placing functions in RAM) should be made to the linker script sections.ld

If you wish to download / debug using NXP's LPC-Link, you will need to edit the LPCINSTALL variable in Makefile to point to the bin/ directory of your LPCXpresso IDE install.

Usage

After making sure sources.mk is up-to-date, simply run make to compile.

If you wish to download / debug using NXP's LPC-Link, run make lpc-link to flash the LPC-Link's own firmware and start a server which can be connected to by GDB. This will not return - you will need to open a new terminal to continue. You can only do this once before you will need to unplug and reconnect (or do some USB trickery to) the LPC-Link.

The makefile picks a random 5-digit port to start the debug server, and modifies the connect command defined in .gdbscript to point to it. Therefore you should run GDB (or more precisely arm-none-eabi-gdb) with the --connect=.gdbscript flag.

sources

make sources is responsible for building sources.mk, which is a list of all the source files in the project (except those listed in the OTHER_SOURCES section of makefile.conf). When run make sources will add every .c and .S file in the sources directory (currently defined as src/) to sources.mk. However this list should be checked by hand to be certain that only the files you intended are being linked into the build.

Emacs

A Directory Local Variables File .dir-locals.el exists in the root of the project, and this has the following effects on emacs:

Fixed default-directory

The default directory is fixed as the root of the project wherever you are within the project. As the makefile needs to be run from the root of the project, this means that M+x compile will always start a compile whichever file you are editing.

Custom GDB

M+x gdb is set to use arm-none-eabi-gdb rather than the default GDB for your machine. GDB is also instructed to read in .gdbscript as a command file.

Other notes

Wherever possible use Function Attributes and Variable Attrubutes rather than editing sections.ld.

Sources & Licensing

See LICENSE.md