[Openocd-svn] r2222 - trunk/src/jtag

[<zw...@ma...>]

Author: zwelch
Date: 2009-06-12 23:43:53 +0200 (Fri, 12 Jun 2009)
New Revision: 2222

Modified:
   trunk/src/jtag/core.c
   trunk/src/jtag/tcl.c
Log:
David Brownell <da...@pa...>:

Partial fix to the "long IR length" problems.

 - Current code could handle up to 32 bit IR lengths with
   full functionality, if it didn't just reject may of them
   out of hand.  So only reject clear errors, where the IR
   mask (or capture instruction) needs more than IrLen bits.

 - Longer IR lengths can only be handled in BYPASS mode
   for now.  Example:  TI's DSPs use 38-bit IR lengths.
   So we can't issue their IDCODE instructions...

A more complete fix would be able to issue longer instructions;
or minimally, would fail cleanly for the non-BYPASS case.

Note that this *could* make some currently broken scripts fail,
since the previous code accepted garbage values so long as
they didn't use more than 16 bits.


Modified: trunk/src/jtag/core.c
===================================================================
--- trunk/src/jtag/core.c	2009-06-12 21:31:11 UTC (rev 2221)
+++ trunk/src/jtag/core.c	2009-06-12 21:43:53 UTC (rev 2222)
@@ -1073,6 +1073,7 @@
 	tap->expected_mask = malloc(tap->ir_length);
 	tap->cur_instr = malloc(tap->ir_length);
 
+	/// @todo cope sanely with ir_length bigger than 32 bits
 	buf_set_u32(tap->expected, 0, tap->ir_length, tap->ir_capture_value);
 	buf_set_u32(tap->expected_mask, 0, tap->ir_length, tap->ir_capture_mask);
 	buf_set_ones(tap->cur_instr, tap->ir_length);

Modified: trunk/src/jtag/tcl.c
===================================================================
--- trunk/src/jtag/tcl.c	2009-06-12 21:31:11 UTC (rev 2221)
+++ trunk/src/jtag/tcl.c	2009-06-12 21:43:53 UTC (rev 2222)
@@ -296,7 +296,16 @@
 	return JIM_OK;
 }
 
+static int is_bad_irval(int ir_length, jim_wide w)
+{
+	jim_wide v = 1;
 
+	v <<= ir_length;
+	v -= 1;
+	v = ~v;
+	return (w & v) != 0;
+}
+
 extern void jtag_tap_init(jtag_tap_t *tap);
 extern void jtag_tap_free(jtag_tap_t *tap);
 
@@ -411,22 +420,28 @@
 				Jim_SetResult_sprintf( goi->interp, "option: %s bad parameter", n->name );
 				return e;
 			}
-			if( (w < 0) || (w > 0xffff) ){
-				/* wacky value */
-				Jim_SetResult_sprintf( goi->interp, "option: %s - wacky value: %d (0x%x)",
-									   n->name, (int)(w), (int)(w));
-				return JIM_ERR;
-			}
 			switch(n->value){
 			case NTAP_OPT_IRLEN:
+				if (w < (jim_wide) sizeof(pTap->ir_capture_value))
+					LOG_WARNING("huge IR length %d", (int) w);
 				pTap->ir_length = w;
 				reqbits &= (~(NTREQ_IRLEN));
 				break;
 			case NTAP_OPT_IRMASK:
+				if (is_bad_irval(pTap->ir_length, w)) {
+					LOG_ERROR("IR mask %x too big",
+							(int) w);
+					return ERROR_FAIL;
+				}
 				pTap->ir_capture_mask = w;
 				reqbits &= (~(NTREQ_IRMASK));
 				break;
 			case NTAP_OPT_IRCAPTURE:
+				if (is_bad_irval(pTap->ir_length, w)) {
+					LOG_ERROR("IR capture %x too big",
+							(int) w);
+					return ERROR_FAIL;
+				}
 				pTap->ir_capture_value = w;
 				reqbits &= (~(NTREQ_IRCAPTURE));
 				break;