target/cortex_m: fix cortex_m reset_config help and check for syntax error

Remove option 'srst' which is not recognized from on-line help and texi.
Check parameter and return syntax error if wrong option is entered.

Change-Id: I87daa423a9f53193a0b015080594820b933628f5
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/4795
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

1 files changed, 7 insertions, 6 deletions

diff --git a/doc/openocd.texi b/doc/openocd.texi
index bc24aedb..aa901e6e 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -3458,6 +3458,7 @@ How long (in milliseconds) OpenOCD should wait after deasserting
 nTRST (active-low JTAG TAP reset) before starting new JTAG operations.
 @end deffn
 
+@anchor {reset_config}
 @deffn {Command} reset_config mode_flag ...
 This command displays or modifies the reset configuration
 of your combination of JTAG board and target in target
@@ -8994,13 +8995,13 @@ must also be explicitly enabled.
 This finishes by listing the current vector catch configuration.
 @end deffn
 
-@deffn Command {cortex_m reset_config} (@option{srst}|@option{sysresetreq}|@option{vectreset})
-Control reset handling. The default @option{srst} is to use srst if fitted,
-otherwise fallback to @option{vectreset}.
+@deffn Command {cortex_m reset_config} (@option{sysresetreq}|@option{vectreset})
+Control reset handling if hardware srst is not fitted
+@xref{reset_config,,reset_config}.
+
 @itemize @minus
-@item @option{srst} use hardware srst if fitted otherwise fallback to @option{vectreset}.
-@item @option{sysresetreq} use NVIC SYSRESETREQ to reset system.
-@item @option{vectreset} use NVIC VECTRESET to reset system.
+@item @option{sysresetreq} use AIRCR SYSRESETREQ to reset system.
+@item @option{vectreset} use AIRCR VECTRESET to reset system (default).
 @end itemize
 
 Using @option{vectreset} is a safe option for Cortex-M3, M4 and M7 cores.