Now that the project has no errors and builds correctly, we can turn our attention to uncovering exactly how our application fits in memory and how to navigate around it.
The Project Explorer is the central focus for arranging your source code into projects, and it's a good place to show ancillary information gathered when CrossStudio builds your applications. This section will cover the features that the Project Explorer offers to give you an overview of your project.
Developers are always interested in how much memory their applications take up, and with small embedded microcontrollers this is especially true. The Project Explorer can display the code and data sizes for each project and individual source file that is successfully compiled. To do this, click the Options dropdown on the Project Explorer tool bar and make sure that Show Code/Data Size is checked. Once checked, the Project Explorer displays two additional columns, Code and Data.
The Code column displays the total code space required for the project (program code and read-only constants) and the Data column displays the total data space required (that is, writable data) excluding that required for the stack. The code and data sizes for each C and assembly source file are estimates, but good estimates nontheless. Because the linker removes any unreferenced code and data and performs a number of optimizations, the sizes for the linked project may not be the sum of the sizes of each individual file. The code and data sizes for the project, however, are accurate. As before, your numbers may not match these exactly.
The Project Explorer is very versatile: not only can you display the code and data sizes for each element of a project and the project as a whole, you can also configure the Project Explorer to show the dependencies for a file. As part of the compilation process, CrossStudio finds and records the relationships between files—that is, it finds which files are dependent upon other files. CrossStudio uses these relationships when it comes ro build the project again so that it does the minimum amount of work to bring the project up to date.
To show the dependencies for a project, click the Options button on the Project Explorer tool bar and ensure that Show Dependencies is checked in the menu. Once checked, dependent files are shown as sub-nodes of the file which depends upon them.
In this case, main.c is dependent upon cross_studio_io.h because it it includes it with a #include directive. You can open cross_studio_io.h in an editor by double clicking it, so having dependencies turned on is an effective way of navigating to and summarising the files that a source file includes.
Another useful piece of information is knowing the files output files when compiling and linking the application. Needless to say, CrossStudio can display this information too. To turn on output file display, click the Options button on the Project Explorer tool bar and ensure that Show Output Files is checked in the menu. Once checled, output files are shown in an Output Files folder underneath the node that generates them.
In the above figure, we can see that the object files fact.hzo, main.hzo, and crt0.hzo are object files produced by compiling their corresponding source files; the map file Tutorial.map and the linked executable Tutorial.hzx are produced by the linker. As a convenience, double clicking an object file or a linked executable file in the Project Explorer will open an editor showing the disassembled contents of the file.
You can disassemble a project either by double clicking the corresponding file as described above, or you can use the Disassemble tool to do it.
To disassemble a project or file, do one of the following:
—or—
CrossStudio opens a new read-only editor and places a disassembled listing into it. If you change your project and rebuild it, causing a change in the object or executable file, the disassembly updates to keep the display up-to-date with the file on disk.
Whilst a map file produced by the linker is traditionally the best way (and in some cases, the only way) to see how your application is laid out im memory, CrossStudio provides a much better way to examine and navigate your application: the Symbol Browser. You can use the Symbol Browser to navigate your application, see which data objects and functions have been linked into your application, what their sizes are, which section they are in, and where they are placed in memory.
To display the Symbol Browser window if it is hidden, do one of the following:
—or—
—or—
The Tutorial project shows this in the Symbol Browser:
From this you can see that the CODE section is 157 bytes in size and is placed in memory between address 0049and 00E5 inclusive. Similarly, the zeroed data section UDATA0 is three bytes in size and is placed between 0017 and 0019, the CONST section that holds string constants and read-only data is 23 bytes in size between 0032 and 0048. You can click the header to order sections by their address by clicking on Range and by their size by clicking Size.
To drill down, open the CODE node by double clicking it: CrossStudio displays the individual functions that have been placed in memory and their sizes:
Here, we can see that main is 46 bytes in size and is placed in memory between addresses 004a and 0077 inclusive and that factorial is 46bytes and occupies addresses 0078 through 00a5. Just as in the Project Explorer, you can double click a function and CrossStudio moves the cursor to the line containing the definition of that function, so you can easily navigate around your application using the Symbol Browser.
You can print the contents of the Symbol Browser by focusing the Symbol Browser window and selecting Print from the File menu, or Print Preview if you want to see what it will look like before printing. CrossStudio prints only the columns that you have selected for display, and prints items in the same order they are displayed in the Symbol Browser, so you can choose which columns to print and how to print symbols by configuring the Symbol Browser display before you print.
We have touched on only some of the features that the Symbol Browser offers; to find out more, refer to Symbol browser where it is described in detail.