ARM11: don't expose WDTR

Don't expose the WDTR register through the register cache any
more.  If anyone wants Tcl scripts to be able to use DCC based
communication with app code in the target, this wouldn't do it.

Bugfix:  don't trust the Tcl-accessible version of DSCR to
flag whether WDTR needs to be restored when resuming.

src/target/arm11.c

@@ -50,7 +50,6 @@ enum arm11_regtype
 {
 	/* debug regs */
 	ARM11_REGISTER_DSCR,
-	ARM11_REGISTER_WDTR,
 };
 
 
@@ -67,13 +66,11 @@ static const struct arm11_reg_defs arm11_reg_defs[] =
 {
 	/* Debug Registers */
 	{"dscr",	0,	-1,	ARM11_REGISTER_DSCR},
-	{"wdtr",	0,	-1,	ARM11_REGISTER_WDTR},
 };
 
 enum arm11_regcache_ids
 {
 	ARM11_RC_DSCR,
-	ARM11_RC_WDTR,
 
 	ARM11_RC_MAX,
 };
@@ -171,8 +168,8 @@ static int arm11_debug_entry(struct arm11_common *arm11, uint32_t dscr)
 	R(DSCR) = dscr;
 
 	/* Save wDTR */
-
-	if (dscr & ARM11_DSCR_WDTR_FULL)
+	arm11->is_wdtr_saved = !!(dscr & ARM11_DSCR_WDTR_FULL);
+	if (arm11->is_wdtr_saved)
 	{
 		arm11_add_debug_SCAN_N(arm11, 0x05, ARM11_TAP_DEFAULT);
 
@@ -180,17 +177,13 @@ static int arm11_debug_entry(struct arm11_common *arm11, uint32_t dscr)
 
 		struct scan_field	chain5_fields[3];
 
-		arm11_setup_field(arm11, 32, NULL, &R(WDTR),	chain5_fields + 0);
+		arm11_setup_field(arm11, 32, NULL,
+				&arm11->saved_wdtr, chain5_fields + 0);
 		arm11_setup_field(arm11,  1, NULL, NULL,		chain5_fields + 1);
 		arm11_setup_field(arm11,  1, NULL, NULL,		chain5_fields + 2);
 
 		arm11_add_dr_scan_vc(ARRAY_SIZE(chain5_fields), chain5_fields, TAP_DRPAUSE);
 	}
-	else
-	{
-		arm11->reg_list[ARM11_RC_WDTR].valid	= 0;
-	}
-
 
 	/* DSCR: set ARM11_DSCR_EXECUTE_ARM_INSTRUCTION_ENABLE
 	 *
@@ -328,14 +321,15 @@ static int arm11_leave_debug_state(struct arm11_common *arm11, bool bpwp)
 	}
 
 	/* maybe restore original wDTR */
-	if ((R(DSCR) & ARM11_DSCR_WDTR_FULL) || arm11->reg_list[ARM11_RC_WDTR].dirty)
+	if (arm11->is_wdtr_saved)
 	{
 		retval = arm11_run_instr_data_prepare(arm11);
 		if (retval != ERROR_OK)
 			return retval;
 
 		/* MCR p14,0,R0,c0,c5,0 */
-		retval = arm11_run_instr_data_to_core_via_r0(arm11, 0xee000e15, R(WDTR));
+		retval = arm11_run_instr_data_to_core_via_r0(arm11,
+				0xee000e15, arm11->saved_wdtr);
 		if (retval != ERROR_OK)
 			return retval;
 

src/target/arm11.h

@@ -26,7 +26,7 @@
 #include "armv4_5.h"
 #include "arm_dpm.h"
 
-#define ARM11_REGCACHE_COUNT		2
+#define ARM11_REGCACHE_COUNT		1
 
 #define ARM11_TAP_DEFAULT			TAP_INVALID
 
@@ -63,8 +63,11 @@ struct arm11_common
 							     Use only for debug message generation		*/
 
 	uint32_t saved_rdtr;
+	uint32_t saved_wdtr;
 
 	bool is_rdtr_saved;
+	bool is_wdtr_saved;
+
 	bool	simulate_reset_on_next_halt;	/**< Perform cleanups of the ARM state on next halt */
 
 	/** \name Shadow registers to save debug state */