diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/jtag/jtag.c | 47 |
1 files changed, 39 insertions, 8 deletions
diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c index fb7429f2..ec233086 100644 --- a/src/jtag/jtag.c +++ b/src/jtag/jtag.c @@ -2955,6 +2955,26 @@ static int handle_runtest_command(struct command_context_s *cmd_ctx, char *cmd, } +/* + * For "irscan" or "drscan" commands, the "end" (really, "next") state + * should be stable ... and *NOT* a shift state, otherwise free-running + * jtag clocks could change the values latched by the update state. + */ +static bool scan_is_safe(tap_state_t state) +{ + switch (state) + { + case TAP_RESET: + case TAP_IDLE: + case TAP_DRPAUSE: + case TAP_IRPAUSE: + return true; + default: + return false; + } +} + + static int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc) { int i; @@ -2967,11 +2987,12 @@ static int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, c return ERROR_COMMAND_SYNTAX_ERROR; } - /* optional "-endstate" */ - /* "statename" */ - /* at the end of the arguments. */ - /* assume none. */ - endstate = cmd_queue_end_state; + /* optional "-endstate" "statename" at the end of the arguments, + * so that e.g. IRPAUSE can let us load the data register before + * entering RUN/IDLE to execute the instruction we load here. + */ + endstate = TAP_IDLE; + if( argc >= 4 ){ /* have at least one pair of numbers. */ /* is last pair the magic text? */ @@ -2988,6 +3009,9 @@ static int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, c if( endstate >= TAP_NUM_STATES ){ return ERROR_COMMAND_SYNTAX_ERROR; } else { + if (!scan_is_safe(endstate)) + LOG_WARNING("irscan with unsafe " + "endstate \"%s\"", cpA); /* found - remove the last 2 args */ argc -= 2; } @@ -3052,8 +3076,8 @@ static int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args return JIM_ERR; } - /* assume no endstate */ - endstate = cmd_queue_end_state; + endstate = TAP_IDLE; + /* validate arguments as numbers */ e = JIM_OK; for (i = 2; i < argc; i+=2) @@ -3073,7 +3097,10 @@ static int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args return e; } - /* it could be: "-endstate FOO" */ + /* it could be: "-endstate FOO" + * e.g. DRPAUSE so we can issue more instructions + * before entering RUN/IDLE and executing them. + */ /* get arg as a string. */ cp = Jim_GetString( args[i], NULL ); @@ -3088,6 +3115,10 @@ static int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args /* update the error message */ Jim_SetResult_sprintf(interp,"endstate: %s invalid", cp ); } else { + if (!scan_is_safe(endstate)) + LOG_WARNING("drscan with unsafe " + "endstate \"%s\"", cp); + /* valid - so clear the error */ e = JIM_OK; /* and remove the last 2 args */ |