ARM

Prerequisites

• Email syscom@csclub.uwaterloo.ca asking to be added to the board group.
• An ARM compiler and build environment. If you do your development on corn-syrup this is already set up for you.
• Basic working knowledge of GNU screen.

Hardware

The TS-7800 is connected by serial port to strombola, one of the office machines. We have ported U-Boot to the board and installed it to the onboard flash memory. U-Boot is used to load a compiled program from our TFTP server over the network. We have also wired the board so that it resets when COM3 is opened; this is used to reset the board when a user program crashes it.

Development Environment

Every CSC machine has a utility called "become_board" installed that is used to connect to the board's console. You must use this program to interact with the board.

The board also sometimes runs a linux environment (goto80.csclub.uwaterloo.ca). It is okay to reset the board while linux is running; don't worry about shutting it down safely.

Rules & Regulations

• Only the systems committee touches the board. You can power cycle the board without touching it. If there is a problem, email syscom@csclub.uwaterloo.ca.
• Try not to reset the board while another user is running their program.

Compiling and Running Your First Program

We have modified the busy-wait I/O library used by CS 452 to work with the TS-7800. The following steps explain how to compile and run the test application on the TS-7800. These steps should be completed on corn-syrup.

• Clone the test git repository from csclub.uwaterloo.ca:/srv/git/arm/ts7800-bwio.git:

git clone csclub.uwaterloo.ca:/srv/git/arm/ts7800-bwio.git
cd ts7800-bwio

• Build the test application:

make CC=arm-linux-gnueabi-gcc

• Create yourself a directory on our TFTP server (caffeine):

ssh caffeine mkdir -p /srv/tftp/ARM/$USER

• Copy the test application (bin/iotest) to your directory on the TFTP server.

scp bin/iotest caffeine:/srv/tftp/ARM/$USER/

• Run become_board to attach to the TS-7800 screen session.

become_board

• Reboot the board from the radreboot window. Press C-a 1 (control-A, then 1) to switch windows, then press enter to reboot.

• Execute your test program on the board. Press C-a 0 (control-A, then 0) to switch windows. Replace $USER by your user name.

tftp ARM/$USER/iotest
bootelf

If all goes well, you should see the following output:

Hello
***Hello
Hello world.
Well, hello world23.
-23 worlds for 1 person.
ffffffe9 worlds for 723 people.

If you press any key the board will reboot.

Further Steps

• Write some ARM assembly. You can start by modifying ts7800.S.
• Work through the CS 452 kernel assignments (skip the train parts). These are available on Bill Cowan's web site.

Troubleshooting

• If the shared screen session is not working properly, such as when an important window is closed, the easiest way to recover is to terminate the screen session entirely and rerun become_board. Press C-a \ (control-A, then backslash) to terminate the screen session. Note that this disconnects everyone and should be used sparingly.

Documentation

• The hardware documentation is available at embeddedarm.com and locally at csclub.uwaterloo.ca/~board/ts7800.