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authorMichel Jaouen <michel.jaouen@stericsson.com>2011-05-09 17:30:55 +0200
committerØyvind Harboe <oyvind.harboe@zylin.com>2011-05-09 21:50:44 +0200
commit53c0fb6ef5edd2292c29d048c93f73e2be5fa4ba (patch)
treee70882caba15fab1e7d337ae8d5c67f5dbeed0af /doc
parent289cecebf068e7f988dcbbc8786f6acc96803963 (diff)
cortex a : smp doc update
Diffstat (limited to 'doc')
-rw-r--r--doc/openocd.texi107
1 files changed, 107 insertions, 0 deletions
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