Segger J-Link User Manual page 79

79
Example
jlinkgdbserver -if SWD
Add. information
Currently, the following values are accepted for <Interface> :
• JTAG
• SWD
• FINE
• 2-wire-JTAG-PIC32
3.3.5.5 -ir
Initializes the CPU register with default values on startup.
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via -noir or the GUI.
Example
jlinkgdbserver -ir
3.3.5.6 -excdbg
Enables exception debugging. Exceptions on ARM CPUs are handled by exception handlers.
Exception debugging makes the debugging of exceptions more user-friendly by passing a
signal to the GDB client and returning to the causative instruction. In order to do this, a
special exception handler is required as follows:
__attribute((naked))
__asm volatile (
" bkpt 10 \\n"
" bx lr \\n"
);
}
The signal passed to the GDB client is the immediate value (10 in the example) of the
software breakpoint instruction. <nSteps> specifies, how many instructions need to be
executed until the exception return occurs. In most cases this will be 2 (which is the default
value), if the handler function is set as the exception handler. If it is called indirectly as a
subroutine from the exception handler, there may be more steps required. It is mandatory
to have the function declared with the "naked" attribute and to have the bx lr instruction
immediately after the software breakpoint instruction. Otherwise the software breakpoint
will be treated as a usual breakpoint.
Syntax
-excdbg <nSteps>
Example
jlinkgdbserver -excdbg 4
3.3.5.7 -jtagconf
Configures a JTAG scan chain with multiple devices on it. <IRPre> is the sum of IRLens of all
devices closer to TDI, where IRLen is the number of bits in the IR (Instruction Register) of
one device. <DRPre> is the number of devices closer to TDI. For more detailed information
J-Link / J-Trace (UM08001)
CHAPTER 3
void OnHardFault(void){
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