Книга: Microsoft Windows Embedded CE 6.0 Exam Preparation Kit

Debugging Techniques for Boot Loaders

Debugging Techniques for Boot Loaders

The boot loader design typically consists of at least two distinctive parts. The first part is written in assembly language and initializes the system before jumping to a second part written in C. If you are using a BLCOMMON-based architecture as illustrated in Figure 4-14, you might not have to debug assembly code. If your device is equipped with a UART, you can use the RETAILMSG macro in C code to send data over a serial output interface to the user for display.

Depending on whether you must debug assembly or C code, the following different debugging techniques are available:

? Assembly code Common debugging techniques for the initial startup code rely on LEDs, such as a debugging board with seven-segment LEDs and UARTs for a serial communication interface, because it is relatively straightforward to access General Purpose Input/Output (GPIO) registers and modify the state of an input/output line.

? C Code Debugging is much easier at the C-code level because you can access advanced communication interfaces and debugging macros.

? Assembly and C code If a hardware debugger (JTAG probe) is available, you can use Platform Builder in conjunction with an eXDI driver to debug the boot loader.

Оглавление книги