kgdb: core changes to support kdb
These are the minimum changes to the kgdb core in order to enable an
API to connect a new front end (kdb) to the debug core.
This patch introduces the dbg_kdb_mode variable controls where the
user level I/O is routed. It will be routed to the gdbstub (kgdb) or
to the kdb front end which is a simple shell available over the kgdboc
connection.
You can switch back and forth between kdb or the gdb stub mode of
operation dynamically. From gdb stub mode you can blindly type
"$3#33", or from the kdb mode you can enter "kgdb" to switch to the
gdb stub.
The logic in the debug core depends on kdb to look for the typical gdb
connection sequences and return immediately with KGDB_PASS_EVENT if a
gdb serial command sequence is detected. That should allow a
reasonably seamless transition between kdb -> gdb without leaving the
kernel exception state. The two gdb serial queries that kdb is
responsible for detecting are the "?" and "qSupported" packets.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb
index 9b5d1d7..78de43a 100644
--- a/lib/Kconfig.kgdb
+++ b/lib/Kconfig.kgdb
@@ -3,7 +3,7 @@
bool
menuconfig KGDB
- bool "KGDB: kernel debugging with remote gdb"
+ bool "KGDB: kernel debugger"
depends on HAVE_ARCH_KGDB
depends on DEBUG_KERNEL && EXPERIMENTAL
help
@@ -57,4 +57,10 @@
information about other strings you could use beyond the
default of V1F100.
+config KGDB_KDB
+ bool "KGDB_KDB: include kdb frontend for kgdb"
+ default n
+ help
+ KDB frontend for kernel
+
endif # KGDB
