Файл: ARM cross development with Eclipse, version 2 (J.P. Lynch, 2005).pdf

Click on “Next” to accept c:/cygwin/usr/local/bin as the OCDRemote installation directory.

Clicking on “Install” will complete the OCDRemote installation.

The Wizard completion screen lets you restart your computer to put OCDRemote into the Windows registry.

Just like the Philips ISP Flash Utility, we should install the Macraigor OCDremote utility as an “external tool” that can be accessed easily from the Eclipse CDT RUN pull-down menu.

Start up Eclipse and, if necessary, switch to the C/C++ perspective by clicking “Window – Open Perspective – Other – C/C++.”

Switching perspectives brings up the C/C++ window (perspective) and this will be remembered when you re-enter Eclipse.

In a procedure similar to installing the Philips Flash Utility as an “External Tool”, click on “Run – External Tools – External Tools …” This will bring up the External Tools dialog.

Click on “New” and replace the name with OCDremote. Use the “browse file system” to find it. It should be in the directory c:/cygwin/usr/local/bin.

The arguments needed to properly start the OCDremote are as follows:

It’s a good idea to not tamper with these values. Click on “Apply” to finish the setup.

Just like the Philips LPC2000 Flash Utility, we’d like to include the OCDremote application in our list of “favorite” External Tools. This allows us to quickly start the OCDremote JTAG server from within Eclipse.

Click on “Run – External Tools – Organize Favorites”

Now click on “Add…” in the Organize External Tools … window and follow that by checking “OCDremote” in the Add External Tools Configurations: window. Click on “OK” to add the OCDremote to the list of favorites.

Now verify that the OCDremote is in the list of External Tools favorites. Click on “Run – External Tools” and see that it’s now included in the list of favorites.

Now is a good time to point out that there’s a handy shortcut button in Eclipse to run the External Tools. Click on the External Tools button’s down arrow to expand the list of available tools.

Click on either of the external tools to start them running.

10 Verifying the PATH Settings

There is one final and very crucial step to make before we complete our tool building. We have to ensure that the Windows PATH environment variable has entries for the Cygwin toolset, the GNUARM toolset and the OCDremote JTAG server.

These are the three paths that must be present in the Windows environment:

c:\cygwin\bin

c:\program files\gnuarm\bin c:\cygwin\usr\local\bin

To verify that these paths are present in Windows and to make changes if required, start the Windows Control Panel by clicking “Start – Control Panel”.

Now click on the “Advanced” tab below.

Now click on the “Environment Variables” button.

In the Environment Variables window, find the line for “Path” in the System Variables box on the bottom, click to select and highlight it and then click on “Edit”.

Take a very careful look at the “Edit System Variable” window (the Path Edit, in this case).

You should see the following paths specified, all separated by semicolons. The path is usually long and complex; you may find the bits and pieces for GNUARM interspersed throughout the path specification. I used cut and paste to place all my path specifications at the beginning of the specification (line); this is not really necessary.

You should see the following paths specified.

c:\cygwin\bin;c:\program files\gnuarm\bin;c:\cygwin\usr\local\bin

If any of the three is not present, now is the time to type them into the path specification.

I’ve found that not properly setting up the Path specification is the most common mistake made in configuring Eclipse to do cross-development.

This completes the setup of Eclipse and all the ancillary tools required to cross develop embedded software for the ARM microcomputer family (Philips LPC2000 family in specific).

If you stayed with me this far, your patience will soon be rewarded!

Or as Yoda would say, “Rewarded soon, your patience will be!”

11 Creating a Simple Eclipse Project

At this point, we have a fully-functioning Eclipse IDE capable of building C/C++ programs for the ARM microprocessor (specifically for the Olimex LPC-P2106 prototype board).

We will now create an Eclipse C project called “demo2106_blink_flash” that will blink the board’s red LED_J which is I/O port P0.7. This demo uses no interrupts and runs totally out of onboard flash memory. It has been intentionally designed to be as simple and as straightforward as possible.

Click on our Eclipse desktop icon to start Eclipse.

Eclipse should start and present the C/C++ perspective as shown below. If not, select “Window - Open Perspective – Other - C/C++” to change to the C++ perspective.

To create a project, select File – New – New Project - Standard Make C Project from the File pull-down menu and click “Next” to continue.

You should see the “New Project” dialog box and enter the project name (demo2106_blink_flash) in the box as shown below. Click on Next to continue.

The New Project dialog box appears next. If you click on the “Make Builder” tab, you’ll notice that Eclipse build command is “make.” Make is provided by the Cygwin GNU tools.

Take the default on the “Build Command”, Eclipse will always issue a “make” command to build your project.

These are the targets that “make” will run when you hit the Build All, Build Project or Clean toolbar buttons.

Let’s remind ourselves that we installed the Cygwin GNU tools earlier in the tutorial and the Windows Explorer will show that the make.exe file is indeed in the directory c:/cygwin/bin, as shown below.

This is a good time to point out the differences between “Build All”, “Build Project” and “Clean.”

This is no different from opening up a DOS command window and typing the command in directly, such as.

> make clean all

If you click “Finish” on the “New Project” dialog, Eclipse will return to the C/C++ Perspective.

Now the C/C++ perspective shows a bona fide project in the “C/C++ projects” box on the left. As of now, there are no source files created.

We can now use Eclipse/CDT’s import feature to copy the source files into the project.

Assuming that you successfully unzipped the “demo2106_blink_flash.zip” project files associated with this tutorial to an empty directory such as c:/scratch, you should have the following source and make files in that directory.

Click on the “File” pull-down menu and then click on “Import.” Then in the “Import” window, click on “File System.”

When the “Import – File System” window appears, click on the “Browse” button. Hunt for the sample project which is stored in the c:/scratch/ directory.

Click on the directory “scratch” and hit the “OK” button in the “Import from directory” window on the left below.

Click on “Select All” in the Import window below right to get the source files selected for import into our project.

Now we have to indicate the destination for our source files. Click on “Browse” on the line to the right that says “Into Folder:”

The proper destination folder appears in the Import Into Folder window below.

Click on the folder name “demo2106_blink_flash” and click “OK.” The directory name “demo2106_blink_flash” should appear in the text box.

Now the Import dialog is completely filled out; we can click on “finish” to actually import the source files into our project.

Now the C/C++ perspective main screen will reappear. Click on the “+” expand symbol in the navigator pane to see if our files have been transferred.

Success is at hand, the expanded Projects view in the Navigator pane on the left shows our imported files.

This is a good place to identify the imported source files.

Description of Project Files

12 Description of the LPC210X.H Include File

Let’s look at the lpc210x.h header file. Double-click on it in the Project pane on the left’

ARM peripherals are memory-mapped, so all I/O registers are defined in this file so you don’t have to type in the absolute memory addresses.

13 Description of the Startup File CRT.S

Now let’s look on the startup assembler file, crt.s. Double-click on it.

This part of the crt.s file has some symbols set to the various stack sizes and mode bits.

This part of the crt.s file sets up the various interrupt modes and stacks.

The label Reset_Handler is the beginning of the code. Recall that the first interrupt vector at address 0x000000 loads the PC with the contents of the address Reset_Addr, which contains the address of the startup code at the label Reset_Handler. This trick, used in the entire vector table, loads a 32-bit constant into the PC and thus can jump to any address in memory space.

Whenever the LPC2106 is reset, the instruction at 0x000000 is executed first; it jumps to Reset_Handler. From that point, we are off and running!

The first part of the startup code above sets up the stacks and the mode bits.

The symbol _stack_end will be defined in the linker command script file demo2106.cmd. Here is how it will be defined. Knowing that the Philips ISP Flash

Loader will use the very top 288 bytes of RAM for its internal stack and variables, we’ll start our application stacks at 0x4000FEE0.

(Note: 0x40010000 – 0x120 = 0x4000FEE0)