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diff --git a/doc/openocd.texi b/doc/openocd.texi index 2c09febd..892661fd 100644 --- a/doc/openocd.texi +++ b/doc/openocd.texi @@ -1679,6 +1679,64 @@ Again using the at91sam7 as an example, this can look like: $_TARGETNAME configure -work-area-phys 0x00200000 \ -work-area-size 0x4000 -work-area-backup 0 @end example +@pxref{Define CPU targets working in SMP} +@anchor{Define CPU targets working in SMP} +@subsection Define CPU targets working in SMP +@cindex SMP +After setting targets, you can define a list of targets working in SMP. + +@example +set _TARGETNAME_1 $_CHIPNAME.cpu1 +set _TARGETNAME_2 $_CHIPNAME.cpu2 +target create $_TARGETNAME_1 cortex_a8 -chain-position $_CHIPNAME.dap \ +-coreid 0 -dbgbase $_DAP_DBG1 +target create $_TARGETNAME_2 cortex_a8 -chain-position $_CHIPNAME.dap \ +-coreid 1 -dbgbase $_DAP_DBG2 +#define 2 targets working in smp. +target smp $_CHIPNAME.cpu2 $_CHIPNAME.cpu1 +@end example +In the above example on cortex_a8, 2 cpus are working in SMP. +In SMP only one GDB instance is created and : +@itemize @bullet +@item a set of hardware breakpoint sets the same breakpoint on all targets in the list. +@item halt command triggers the halt of all targets in the list. +@item resume command triggers the write context and the restart of all targets in the list. +@item following a breakpoint: the target stopped by the breakpoint is displayed to the GDB session. +@item dedicated GDB serial protocol packets are implemented for switching/retrieving the target +displayed by the GDB session @pxref{Using openocd SMP with GDB}. +@end itemize + +The SMP behaviour can be disabled/enabled dynamically. On cortex_a8 following +command have been implemented. +@itemize @bullet +@item cortex_a8 smp_on : enable SMP mode, behaviour is as described above. +@item cortex_a8 smp_off : disable SMP mode, the current target is the one +displayed in the GDB session, only this target is now controlled by GDB +session. This behaviour is useful during system boot up. +@item cortex_a8 smp_gdb : display/fix the core id displayed in GDB session see +following example. +@end itemize + +@example +>cortex_a8 smp_gdb +gdb coreid 0 -> -1 +#0 : coreid 0 is displayed to GDB , +#-> -1 : next resume triggers a real resume +> cortex_a8 smp_gdb 1 +gdb coreid 0 -> 1 +#0 :coreid 0 is displayed to GDB , +#->1 : next resume displays coreid 1 to GDB +> resume +> cortex_a8 smp_gdb +gdb coreid 1 -> 1 +#1 :coreid 1 is displayed to GDB , +#->1 : next resume displays coreid 1 to GDB +> cortex_a8 smp_gdb -1 +gdb coreid 1 -> -1 +#1 :coreid 1 is displayed to GDB, +#->-1 : next resume triggers a real resume +@end example + @subsection Chip Reset Setup @@ -7275,6 +7333,55 @@ $_TARGETNAME configure -event EVENTNAME BODY To verify any flash programming the GDB command @option{compare-sections} can be used. +@anchor{Using openocd SMP with GDB} +@section Using openocd SMP with GDB +@cindex SMP +For SMP support following GDB serial protocol packet have been defined : +@itemize @bullet +@item j - smp status request +@item J - smp set request +@end itemize + +OpenOCD implements : +@itemize @bullet +@item @option{jc} packet for reading core id displayed by +GDB connection. Reply is @option{XXXXXXXX} (8 hex digits giving core id) or + @option{E01} for target not smp. +@item @option{JcXXXXXXXX} (8 hex digits) packet for setting core id displayed at next GDB continue +(core id -1 is reserved for returning to normal resume mode). Reply @option{E01} +for target not smp or @option{OK} on success. +@end itemize + +Handling of this packet within GDB can be done : +@itemize @bullet +@item by the creation of an internal variable (i.e @option{_core}) by mean +of function allocate_computed_value allowing following GDB command. +@example +set $_core 1 +#Jc01 packet is sent +print $_core +#jc packet is sent and result is affected in $ +@end example + +@item by the usage of GDB maintenance command as described in following example (2 +cpus in SMP with core id 0 and 1 @pxref{Define CPU targets working in SMP}). + +@example +# toggle0 : force display of coreid 0 +define toggle0 +maint packet Jc0 +continue +main packet Jc-1 +end +# toggle1 : force display of coreid 1 +define toggle1 +maint packet Jc1 +continue +main packet Jc-1 +end +@end example +@end itemize + @node Tcl Scripting API @chapter Tcl Scripting API |