Sets a software instruction breakpoint at the specified memory location. Software breakpoints are implemented by writing a special instruction at the break address, and so cannot be set in ROM.
BREAKINSTRUCTIONqualifier...] expression [=threads,...] [;macro-call]
where:
qualifierIs an ordered list of zero or more qualifiers. The possible qualifiers are described in List of qualifiers for the BREAKINSTRUCTION command.
expressionSpecifies the address at which the breakpoint is placed. By default, this is the address where program execution stops.
threadsThe list of threads that make up the break trigger group.
Only available for OS-aware RSD connections.
macro-callSpecifies a macro and any parameters it requires. The macro runs when the breakpoint activates and before the instruction at the breakpoint is executed. The macro is treated as being specified last in the qualifier list.
If the macro returns a nonzero value, or you specified
continuein the qualifiers, execution continues. If the macro returns zero, or if you do not specify a macro, target execution stops and the debugger waits in command mode.The macro argument symbols are interpreted when the breakpoint is specified and so they must be in scope at that point, or you must explicitly qualify them.
BREAKINSTRUCTION is used to set or modify software address breakpoints. Software address breakpoints include breakpoints set by patching special instructions into the program and hardware that tests the address and data values. If the command has no arguments, it behaves like DTBREAK on DTBREAK, listing the current breakpoints.
If you try to set a software breakpoint at a location in ROM
or Flash, the attempt fails by default. However, if you use the failover qualifier,
RealView Debugger attempts to set a hardware breakpoint instead.
The attempt fails if insufficient hardware facilities are available.
You can use qualifiers evaluated in the debugger, such as expressions, macros, C++ object tests, and software pass counters. You can also define actions to occur when the breakpoint is triggered (hit), including updating counters or windows, and the enabling or disabling of other breakpoints (see List of qualifiers for the BREAKINSTRUCTION command).
When a software breakpoint instruction is hit on the target, the following sequence of events occurs:
The debugger associates the address with a specific breakpoint ID. A memory address can only be associated with one user breakpoint at a time.
If the breakpoint has a pass count associated with it, the count is updated.
The conditions for this breakpoint, if any, are tested in the order specified on the command line (see Qualifiers that define conditional breakpoints). If any condition is False, target execution resumes with the instruction at the breakpointed location. Macros specified with the
macro:qualifier or the;argument are run in this phase.macro-callIf the breakpoint has actions associated with it (for example, using
timedto note the time the breakpoint occurred) these actions are run, in the order specified on the command line (see Qualifiers that define breakpoint actions).If the qualifiers include
continue, target execution resumes with the instruction at the breakpointed location. If not, the debugger updates the state of the GUI and waits for a command, leaving the application halted.
If you are debugging multiprocessor applications, and you have set up synchronization and cross-triggering, then you can specify how each processor is affected when a breakpoint activates.
RealView Debugger assigns a breakpoint list index number to each breakpoint. This number is assigned consecutively. However, if you delete a breakpoint, then the numbering might no longer be consecutive.
To determine the breakpoint list index of an existing breakpoint:
Start RealView Debugger in GUI mode.
Select View → Break/Tracepoints from the Code window main menu to open the Break/Tracepoint view.
Select the checkbox for the chosen breakpoint to disable it.
Click the Cmd tab in the Output view.
The breakpoint list index (
numberdisable,hnumberSelect the checkbox for the chosen breakpoint to enable it.
To set up a conditional breakpoint, use one or more of the following condition qualifiers:
macro(or;)macro-callobjpasscountwhenwhen_not.
The list of qualifiers is dependent on the processor and Debug Interface, and so the GUI does not present things that do not make sense. The command handler generates an error if a specific combination is invalid for a specific processor or Debug Interface, but this is determined when you issue the command.
The possible qualifiers are:
append:(n)Instead of creating a new breakpoint, append the qualifiers specified with this command to an existing breakpoint with breakpoint list index number
ncontinueExecution continues when the breakpoint activates and no breakpoint details are displayed. Any specified action qualifiers are still performed, depending on the results of any condition qualifiers.
failoverWhen you attempt to set a software breakpoint in read-only memory, the default behavior causes the operation to fail. The error message displayed depends on whether or not memory mapping is enabled:
Memory mapping enabled:
Error V004E (Vehicle): Memory map forbids software breakpoint at this address
Memory mapping disabled:
Error V2801C (Vehicle): 0x050b0001: Unable to write sw breakpoint to memory.
However, in some circumstances it might be useful to convert the software breakpoint to a hardware breakpoint. To do this, use the
failoverqualifier.macro:{MacroCall(arg1,arg2)}When the breakpoint is hit, the specified macro is executed. Any program variables or functions must be in scope at the time the breakpoint request is entered, or the names must be fully qualified. A macro call specified here is treated in the same way as a macro specified after a
;. You must include the braces{and}.message:{"$windowid|fileid$message"}Activation of the breakpoint results in
messagemessage$enables you to write the message text to a user-defined window or file. For example:windowid|fileid$BREAKINSTRUCTION,message:{"$100$this is a message"}modify:(n)Instead of creating a new breakpoint, modify the breakpoint with breakpoint list index number
nobj:(n)This condition is True if the argument
nthis.passcount:(n)Specifies the number of times that the break condition is ignored before the breakpoint activates. The default value is 0. If you specify this in the middle of a sequence of break conditions, those specified before the passcount are processed whether or not the count reaches zero. The conditions specified afterwards are run only when the count reaches zero.
rtos:typeSets a breakpoint for OS-aware connections, where
typehsdSets a Halted System Debug (HSD) breakpoint for debugging your OS-aware image.
processNot supported in this release.
systemSets a system breakpoint for debugging images running in Running System Debug (RSD) mode.
threadSets a thread breakpoint for debugging images running in RSD mode.
size:nSet the size of the breakpoint to either 16 or 32 bits. For example:
BREAKINSTRUCTION,size:32 0x10040
Use this qualifier if no debug information is available for your image. By default, RealView Debugger sets a 32-bit breakpoint.
update:{"name"}Update the named windows, or all windows, by reading the memory and processor state when the breakpoint activates. You can use the name
allto refresh all windows, or a name specified in the title bar of the window.This qualifier enables you to get an overview of the process state at a particular point, without having to manually restart the process at each break. The update still takes a significant period of time, and so this method is unsuitable as a non-intrusive debugging tool.
when:{condition}The breakpoint activatesactivates whenever
conditionNote
Using a macro as an argument to
when, reverses the sense of the return value from the macro.when_not:{condition}The breakpoint activates whenever
condition
The following rules apply to the use of the BREAKINSTRUCTION command:
Breakpoints are specific to the board, process, or task active in the window at the time they are set.
If synchronous breakpoints are set on two or more threads on the same board, the debugger stops the threads as close to the same time as the architecture of the board permits.
The following examples show how to use BREAKINSTRUCTION:
BREAKINSTRUCTION 0x8000Set a breakpoint at address
0x8000.BREAKINSTRUCTION \MATH_1\MATH_C\#449:22Set a breakpoint at line 449, column 22 in the file
math.c.BREAKINSTRUCTION,append:(1),continue,update:{all}Given an already set breakpoint at position 1 in the breakpoint list, add a request to update all windows in the code window for this connection and continue execution each time the breakpoint activates.
BREAKINSTRUCTION,pass:(5) \MAIN_1\MAIN_C\#49Set a breakpoint using a hardware counter to stop at the fifth time that execution reaches line 49 of
main.c.BREAKINSTRUCTION \MAIN_1\MAIN_C\#33 ;CheckStruct()Set a breakpoint that calls a debugger macro
CheckStructeach time it reaches line 33 ofmain.c. IfCheckStructreturns a nonzero value, the debugger continues application execution.BREAKINSTRUCTION,when:{count<4 || err==5} \MAIN_1\SUBFN_C\#33Set a breakpoint that activates when the expression
count<4 || err==5is True when execution reaches line 33 ofsubfn.c.BREAKINSTRUCTION,when:{check_struct()} \MAIN_1\MAIN_C\#33Set a breakpoint that calls a target program function
check_struct()each time it reaches line 33 ofmain.c. If this function returns zero, the debugger continues application execution.BREAKINSTRUCTION, rtos:hsd \DEMO\#201Set a HSD breakpoint at line
201indemo.c.BREAKINSTRUCTION,rtos:system \DEMO\#154Set a system breakpoint at line
154indemo.c.BREAKINSTRUCTION,rtos:thread \DEMO\#154 = 0x39d8, 0x3a68Set a thread breakpoint using a break trigger group consisting of two threads, defined by the addresses of the thread control blocks.
BREAKINSTRUCTION,rtos:thread \DEMO\#180 = thread_2, thread_6, thread_8Set a thread breakpoint using a break trigger group consisting of three threads, defined by the thread names.
BREAKINSTRUCTION,modify:2,rtos:systemModify breakpoint number 2, a thread breakpoint, to be a system breakpoint.
BREAKINSTRUCTION,modify:3,rtos:thread = 0x1395c, 0x13bacModify breakpoint number 3, a thread breakpoint, to specify a different break trigger group, shown in Figure 2.1.
the following in the RealView Debugger User Guide:
the following in the RealView Debugger RTOS Guide:
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