cc2640r2_blinky

Baremetal blinky example for the TI CC2640R2 Launchpad. Makes uses of GCC, Make, and OpenOCD.

Summary

This is an example project for the TI CC2640R2 Launchpad, designed to be built using standard tools. Code Composer Studio (aka CCS) is not required to build, flash, or debug this project, i.e. it can all be done via the command line.

Dependencies

• arm-none-eabi-gcc with Cortex-M3 support. Any recent build, either from ARM or from your distro's official package repositories should work.
• openocd from a recent version. The changes to support the CC2640 are very new (as of 2018), so it is highly recommended to build from Git.
• The TI CC2640R2 SDK must be installed. Currently this is available only as a Windows installer, but the files can be installed via WINE and then copied elsewhere.

Building

1. Ensure the CC2640_SDK env var points to your installation of the SDK, for example:

• export CC2640_SDK="/opt/ti/simplelink_cc2640r2_sdk_1_50_00_58"

2. If using a GCC installation that is not in your $PATH, modify $CC2640_SDK/imports.mak to point to the correct GCC_ARMCOMPILER location.
3. Run make in the project root.

Debugging

1. After building, connect the Launchpad and run make flash. This will use OpenOCD to program the board.
2. After a successful flash, the board should be running. To connect GDB:

• Run openocd. This should create a GDB server running on port :3333.
• In another terminal, launch arm-none-eabi-gdb blinky.elf. If the .gdbinit file is sourced, it will connect to OpenOCD automatically. Otherwise, within GDB, issue target remote :3333

3. Reset the board by issuing monitor reset init followed by set $pc=$pc (this is a workaround to resync GDB's program counter).
4. You may now set breakpoints and otherwise control the CPU via GDB.

Known Issues

• The XDS110 debug adapter chip that comes on the Launchpad will need updated firmware for OpenOCD support. Otherwise, OpenOCD will refuse to connect to the adapter. Note that the easiest way to update the firmware is via Code Composer Studio's update tools.
• In order to connect to the XDS110 as a normal user, it is required to install udev rules to give the appropriate permissions. The CCS install comes with a file that can be used to give permissions for TI devices, however its permissions are broader than needed for this project.
• The CC2640 support in OpenOCD is still in beta. A regular monitor reset command will cause the JTAG to lose connection, as will low-power modes on the CC2640. The openocd.cfg file remaps reset so that it does not issue a regular chip reset (see Debugging).
• The XDS110 USB support in Linux is not stable under VirtualBox. Often times the connection will be made, but die within ten seconds. The board must be power-cycled after this occurs.
• For additional caveats, please check TI's official OpenOCD download page.
• These scripts do not currently check if OpenOCD is running. If it is, you will have to kill it before running make flash to update the image. ​