ARM920T scanchain 15 comments/cleanup

For folk who don't know the ARM920 JTAG interface very well, the
two modes of scan chain 15 access to CP15 are confusing.

Make those parts of the ARM920 code less opaque, by:

 - Adding comments referencing the relevant parts of the TRM,
   catching up to similar updates in the User's Guide.

 - Replacing magic numbers in physical access clients with
   symbolic equivalents.

No functional change.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

1 files changed, 112 insertions, 51 deletions

diff --git a/src/target/arm920t.c b/src/target/arm920t.c
index e04d9fca..3b75ca97 100644
--- a/src/target/arm920t.c
+++ b/src/target/arm920t.c
@@ -42,7 +42,8 @@
  *   6 ... ETM9
  *   15 ... access coprocessor 15, "physical" or "interpreted" modes
  *	"interpreted" works with a few actual MRC/MCR instructions
- *	"physical" provides register-like behaviors.
+ *	"physical" provides register-like behaviors.  Section 9.6.7
+ *	covers these details.
  *
  * The ARM922T is similar, but with smaller caches (8K each, vs 16K).
  */
@@ -51,8 +52,33 @@
 #define _DEBUG_INSTRUCTION_EXECUTION_
 #endif
 
+/* Table 9-8 shows scan chain 15 format during physical access mode, using a
+ * dedicated 6-bit address space (encoded in bits 33:38).  Writes use one
+ * JTAG scan, while reads use two.
+ *
+ * Table 9-9 lists the thirteen registers which support physical access.
+ * ARM920T_CP15_PHYS_ADDR() constructs the 6-bit reg_addr parameter passed
+ * to arm920t_read_cp15_physical() and arm920t_write_cp15_physical().
+ *
+ *  x == bit[38]
+ *  y == bits[37:34]
+ *  z == bit[33]
+ */
 #define ARM920T_CP15_PHYS_ADDR(x, y, z) ((x << 5) | (y << 1) << (z))
 
+/* Registers supporting physical Read access (from table 9-9) */
+#define CP15PHYS_CACHETYPE	ARM920T_CP15_PHYS_ADDR(0, 0x0, 1)
+#define CP15PHYS_ICACHE_IDX	ARM920T_CP15_PHYS_ADDR(1, 0xd, 1)
+#define CP15PHYS_DCACHE_IDX	ARM920T_CP15_PHYS_ADDR(1, 0xe, 1)
+/* NOTE: several more registers support only physical read access */
+
+/* Registers supporting physical Read/Write access (from table 9-9) */
+#define CP15PHYS_CTRL		ARM920T_CP15_PHYS_ADDR(0, 0x1, 0)
+#define CP15PHYS_PID		ARM920T_CP15_PHYS_ADDR(0, 0xd, 0)
+#define CP15PHYS_TESTSTATE	ARM920T_CP15_PHYS_ADDR(0, 0xf, 0)
+#define CP15PHYS_ICACHE		ARM920T_CP15_PHYS_ADDR(1, 0x1, 1)
+#define CP15PHYS_DCACHE		ARM920T_CP15_PHYS_ADDR(1, 0x2, 1)
+
 static int arm920t_read_cp15_physical(struct target *target,
 		int reg_addr, uint32_t *value)
 {
@@ -153,6 +179,13 @@ static int arm920t_write_cp15_physical(struct target *target,
 	return ERROR_OK;
 }
 
+/* See table 9-10 for scan chain 15 format during interpreted access mode.
+ * If the TESTSTATE register is set for interpreted access, certain CP15
+ * MRC and MCR instructions may be executed through scan chain 15.
+ *
+ * Tables 9-11, 9-12, and 9-13 show which MRC and MCR instructions can be
+ * executed using scan chain 15 interpreted mode.
+ */
 static int arm920t_execute_cp15(struct target *target, uint32_t cp15_opcode,
 		uint32_t arm_opcode)
 {
@@ -225,17 +258,17 @@ static int arm920t_read_cp15_interpreted(struct target *target,
 
 	/* read-modify-write CP15 test state register
 	* to enable interpreted access mode */
-	arm920t_read_cp15_physical(target, 0x1e, &cp15c15);
+	arm920t_read_cp15_physical(target, CP15PHYS_TESTSTATE, &cp15c15);
 	jtag_execute_queue();
 	cp15c15 |= 1;	/* set interpret mode */
-	arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+	arm920t_write_cp15_physical(target, CP15PHYS_TESTSTATE, cp15c15);
 
 	/* execute CP15 instruction and ARM load (reading from coprocessor) */
 	arm920t_execute_cp15(target, cp15_opcode, ARMV4_5_LDR(0, 1));
 
 	/* disable interpreted access mode */
 	cp15c15 &= ~1U;	/* clear interpret mode */
-	arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+	arm920t_write_cp15_physical(target, CP15PHYS_TESTSTATE, cp15c15);
 
 	/* retrieve value from R0 */
 	regs_p[0] = value;
@@ -271,17 +304,17 @@ int arm920t_write_cp15_interpreted(struct target *target,
 
 	/* read-modify-write CP15 test state register
 	* to enable interpreted access mode */
-	arm920t_read_cp15_physical(target, 0x1e, &cp15c15);
+	arm920t_read_cp15_physical(target, CP15PHYS_TESTSTATE, &cp15c15);
 	jtag_execute_queue();
 	cp15c15 |= 1;	/* set interpret mode */
-	arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+	arm920t_write_cp15_physical(target, CP15PHYS_TESTSTATE, cp15c15);
 
 	/* execute CP15 instruction and ARM store (writing to coprocessor) */
 	arm920t_execute_cp15(target, cp15_opcode, ARMV4_5_STR(0, 1));
 
 	/* disable interpreted access mode */
 	cp15c15 &= ~1U;	/* set interpret mode */
-	arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+	arm920t_write_cp15_physical(target, CP15PHYS_TESTSTATE, cp15c15);
 
 #ifdef _DEBUG_INSTRUCTION_EXECUTION_
 	LOG_DEBUG("cp15_opcode: %8.8x, value: %8.8x, address: %8.8x", cp15_opcode, value, address);
@@ -314,7 +347,7 @@ void arm920t_disable_mmu_caches(struct target *target, int mmu, int d_u_cache, i
 	uint32_t cp15_control;
 
 	/* read cp15 control register */
-	arm920t_read_cp15_physical(target, 0x2, &cp15_control);
+	arm920t_read_cp15_physical(target, CP15PHYS_CTRL, &cp15_control);
 	jtag_execute_queue();
 
 	if (mmu)
@@ -326,7 +359,7 @@ void arm920t_disable_mmu_caches(struct target *target, int mmu, int d_u_cache, i
 	if (i_cache)
 		cp15_control &= ~0x1000U;
 
-	arm920t_write_cp15_physical(target, 0x2, cp15_control);
+	arm920t_write_cp15_physical(target, CP15PHYS_CTRL, cp15_control);
 }
 
 // EXPORTED to FA256
@@ -335,7 +368,7 @@ void arm920t_enable_mmu_caches(struct target *target, int mmu, int d_u_cache, in
 	uint32_t cp15_control;
 
 	/* read cp15 control register */
-	arm920t_read_cp15_physical(target, 0x2, &cp15_control);
+	arm920t_read_cp15_physical(target, CP15PHYS_CTRL, &cp15_control);
 	jtag_execute_queue();
 
 	if (mmu)
@@ -347,7 +380,7 @@ void arm920t_enable_mmu_caches(struct target *target, int mmu, int d_u_cache, in
 	if (i_cache)
 		cp15_control |= 0x1000U;
 
-	arm920t_write_cp15_physical(target, 0x2, cp15_control);
+	arm920t_write_cp15_physical(target, CP15PHYS_CTRL, cp15_control);
 }
 
 // EXPORTED to FA256
@@ -357,7 +390,8 @@ void arm920t_post_debug_entry(struct target *target)
 	struct arm920t_common *arm920t = target_to_arm920(target);
 
 	/* examine cp15 control reg */
-	arm920t_read_cp15_physical(target, 0x2, &arm920t->cp15_control_reg);
+	arm920t_read_cp15_physical(target,
+			CP15PHYS_CTRL, &arm920t->cp15_control_reg);
 	jtag_execute_queue();
 	LOG_DEBUG("cp15_control_reg: %8.8" PRIx32 "", arm920t->cp15_control_reg);
 
@@ -365,7 +399,8 @@ void arm920t_post_debug_entry(struct target *target)
 	{
 		uint32_t cache_type_reg;
 		/* identify caches */
-		arm920t_read_cp15_physical(target, 0x1, &cache_type_reg);
+		arm920t_read_cp15_physical(target,
+				CP15PHYS_CACHETYPE, &cache_type_reg);
 		jtag_execute_queue();
 		armv4_5_identify_cache(cache_type_reg, &arm920t->armv4_5_mmu.armv4_5_cache);
 	}
@@ -387,10 +422,12 @@ void arm920t_post_debug_entry(struct target *target)
 	{
 		/* read-modify-write CP15 test state register
 		 * to disable I/D-cache linefills */
-		arm920t_read_cp15_physical(target, 0x1e, &cp15c15);
+		arm920t_read_cp15_physical(target,
+				CP15PHYS_TESTSTATE, &cp15c15);
 		jtag_execute_queue();
 		cp15c15 |= 0x600;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 	}
 }
 
@@ -410,10 +447,12 @@ void arm920t_pre_restore_context(struct target *target)
 	* to reenable I/D-cache linefills */
 	if (arm920t->preserve_cache)
 	{
-		arm920t_read_cp15_physical(target, 0x1e, &cp15c15);
+		arm920t_read_cp15_physical(target,
+				CP15PHYS_TESTSTATE, &cp15c15);
 		jtag_execute_queue();
 		cp15c15 &= ~0x600U;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 	}
 }
 
@@ -720,17 +759,17 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 		regs_p[i] = &regs[i];
 
 	/* disable MMU and Caches */
-	arm920t_read_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0x1, 0), &cp15_ctrl);
+	arm920t_read_cp15_physical(target, CP15PHYS_CTRL, &cp15_ctrl);
 	if ((retval = jtag_execute_queue()) != ERROR_OK)
 	{
 		return retval;
 	}
 	cp15_ctrl_saved = cp15_ctrl;
 	cp15_ctrl &= ~(ARMV4_5_MMU_ENABLED | ARMV4_5_D_U_CACHE_ENABLED | ARMV4_5_I_CACHE_ENABLED);
-	arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0x1, 0), cp15_ctrl);
+	arm920t_write_cp15_physical(target, CP15PHYS_CTRL, cp15_ctrl);
 
 	/* read CP15 test state register */
-	arm920t_read_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), &cp15c15);
+	arm920t_read_cp15_physical(target, CP15PHYS_TESTSTATE, &cp15c15);
 	jtag_execute_queue();
 
 	/* read DCache content */
@@ -747,17 +786,20 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 		/* set interpret mode */
 		cp15c15 |= 0x1;
-		arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* D CAM Read, loads current victim into C15.C.D.Ind */
 		arm920t_execute_cp15(target, ARMV4_5_MCR(15,2,0,15,6,2), ARMV4_5_LDR(1, 0));
 
 		/* read current victim */
-		arm920t_read_cp15_physical(target, 0x3d, &C15_C_D_Ind);
+		arm920t_read_cp15_physical(target,
+				CP15PHYS_DCACHE_IDX, &C15_C_D_Ind);
 
 		/* clear interpret mode */
 		cp15c15 &= ~0x1;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		for (index = 0; index < 64; index++)
 		{
@@ -767,7 +809,8 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 			/* set interpret mode */
 			cp15c15 |= 0x1;
-			arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+			arm920t_write_cp15_physical(target,
+					CP15PHYS_TESTSTATE, cp15c15);
 
 			/* Write DCache victim */
 			arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,9,1,0), ARMV4_5_LDR(1, 0));
@@ -780,7 +823,8 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 			/* clear interpret mode */
 			cp15c15 &= ~0x1;
-			arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+			arm920t_write_cp15_physical(target,
+					CP15PHYS_TESTSTATE, cp15c15);
 
 			/* read D RAM and CAM content */
 			arm9tdmi_read_core_regs(target, 0x3fe, regs_p);
@@ -809,14 +853,16 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 		/* set interpret mode */
 		cp15c15 |= 0x1;
-		arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* Write DCache victim */
 		arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,9,1,0), ARMV4_5_LDR(1, 0));
 
 		/* clear interpret mode */
 		cp15c15 &= ~0x1;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 	}
 
 	/* read ICache content */
@@ -833,17 +879,20 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 		/* set interpret mode */
 		cp15c15 |= 0x1;
-		arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* I CAM Read, loads current victim into C15.C.I.Ind */
 		arm920t_execute_cp15(target, ARMV4_5_MCR(15,2,0,15,5,2), ARMV4_5_LDR(1, 0));
 
 		/* read current victim */
-		arm920t_read_cp15_physical(target, 0x3b, &C15_C_I_Ind);
+		arm920t_read_cp15_physical(target, CP15PHYS_ICACHE_IDX,
+				&C15_C_I_Ind);
 
 		/* clear interpret mode */
 		cp15c15 &= ~0x1;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		for (index = 0; index < 64; index++)
 		{
@@ -853,7 +902,8 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 			/* set interpret mode */
 			cp15c15 |= 0x1;
-			arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+			arm920t_write_cp15_physical(target,
+					CP15PHYS_TESTSTATE, cp15c15);
 
 			/* Write ICache victim */
 			arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,9,1,1), ARMV4_5_LDR(1, 0));
@@ -866,7 +916,8 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 			/* clear interpret mode */
 			cp15c15 &= ~0x1;
-			arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+			arm920t_write_cp15_physical(target,
+					CP15PHYS_TESTSTATE, cp15c15);
 
 			/* read I RAM and CAM content */
 			arm9tdmi_read_core_regs(target, 0x3fe, regs_p);
@@ -894,18 +945,20 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 		/* set interpret mode */
 		cp15c15 |= 0x1;
-		arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* Write ICache victim */
 		arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,9,1,1), ARMV4_5_LDR(1, 0));
 
 		/* clear interpret mode */
 		cp15c15 &= ~0x1;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 	}
 
 	/* restore CP15 MMU and Cache settings */
-	arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0x1, 0), cp15_ctrl_saved);
+	arm920t_write_cp15_physical(target, CP15PHYS_CTRL, cp15_ctrl_saved);
 
 	command_print(CMD_CTX, "cache content successfully output to %s", CMD_ARGV[0]);
 
@@ -972,17 +1025,17 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 		regs_p[i] = &regs[i];
 
 	/* disable MMU and Caches */
-	arm920t_read_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0x1, 0), &cp15_ctrl);
+	arm920t_read_cp15_physical(target, CP15PHYS_CTRL, &cp15_ctrl);
 	if ((retval = jtag_execute_queue()) != ERROR_OK)
 	{
 		return retval;
 	}
 	cp15_ctrl_saved = cp15_ctrl;
 	cp15_ctrl &= ~(ARMV4_5_MMU_ENABLED | ARMV4_5_D_U_CACHE_ENABLED | ARMV4_5_I_CACHE_ENABLED);
-	arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0x1, 0), cp15_ctrl);
+	arm920t_write_cp15_physical(target, CP15PHYS_CTRL, cp15_ctrl);
 
 	/* read CP15 test state register */
-	arm920t_read_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), &cp15c15);
+	arm920t_read_cp15_physical(target, CP15PHYS_TESTSTATE, &cp15c15);
 	if ((retval = jtag_execute_queue()) != ERROR_OK)
 	{
 		return retval;
@@ -993,14 +1046,14 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 	/* set interpret mode */
 	cp15c15 |= 0x1;
-	arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+	arm920t_write_cp15_physical(target, CP15PHYS_TESTSTATE, cp15c15);
 
 	/* Read D TLB lockdown */
 	arm920t_execute_cp15(target, ARMV4_5_MRC(15,0,0,10,0,0), ARMV4_5_LDR(1, 0));
 
 	/* clear interpret mode */
 	cp15c15 &= ~0x1;
-	arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+	arm920t_write_cp15_physical(target, CP15PHYS_TESTSTATE, cp15c15);
 
 	/* read D TLB lockdown stored to r1 */
 	arm9tdmi_read_core_regs(target, 0x2, regs_p);
@@ -1019,7 +1072,8 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 		/* set interpret mode */
 		cp15c15 |= 0x1;
-		arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* Write D TLB lockdown */
 		arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,10,0,0), ARMV4_5_STR(1, 0));
@@ -1029,7 +1083,8 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 		/* clear interpret mode */
 		cp15c15 &= ~0x1;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* read D TLB CAM content stored to r2-r9 */
 		arm9tdmi_read_core_regs(target, 0x3fc, regs_p);
@@ -1051,7 +1106,8 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 		/* set interpret mode */
 		cp15c15 |= 0x1;
-		arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* Write D TLB lockdown */
 		arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,10,0,0), ARMV4_5_STR(1, 0));
@@ -1064,7 +1120,8 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 		/* clear interpret mode */
 		cp15c15 &= ~0x1;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* read D TLB RAM content stored to r2 and r3 */
 		arm9tdmi_read_core_regs(target, 0xc, regs_p);
@@ -1089,14 +1146,14 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 	/* set interpret mode */
 	cp15c15 |= 0x1;
-	arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+	arm920t_write_cp15_physical(target, CP15PHYS_TESTSTATE, cp15c15);
 
 	/* Read I TLB lockdown */
 	arm920t_execute_cp15(target, ARMV4_5_MRC(15,0,0,10,0,1), ARMV4_5_LDR(1, 0));
 
 	/* clear interpret mode */
 	cp15c15 &= ~0x1;
-	arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+	arm920t_write_cp15_physical(target, CP15PHYS_TESTSTATE, cp15c15);
 
 	/* read I TLB lockdown stored to r1 */
 	arm9tdmi_read_core_regs(target, 0x2, regs_p);
@@ -1115,7 +1172,8 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 		/* set interpret mode */
 		cp15c15 |= 0x1;
-		arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* Write I TLB lockdown */
 		arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,10,0,1), ARMV4_5_STR(1, 0));
@@ -1125,7 +1183,8 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 		/* clear interpret mode */
 		cp15c15 &= ~0x1;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* read I TLB CAM content stored to r2-r9 */
 		arm9tdmi_read_core_regs(target, 0x3fc, regs_p);
@@ -1147,7 +1206,8 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 		/* set interpret mode */
 		cp15c15 |= 0x1;
-		arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0xf, 0), cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* Write I TLB lockdown */
 		arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,10,0,1), ARMV4_5_STR(1, 0));
@@ -1160,7 +1220,8 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 		/* clear interpret mode */
 		cp15c15 &= ~0x1;
-		arm920t_write_cp15_physical(target, 0x1e, cp15c15);
+		arm920t_write_cp15_physical(target,
+				CP15PHYS_TESTSTATE, cp15c15);
 
 		/* read I TLB RAM content stored to r2 and r3 */
 		arm9tdmi_read_core_regs(target, 0xc, regs_p);
@@ -1181,7 +1242,7 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 	arm920t_execute_cp15(target, ARMV4_5_MCR(15,0,0,10,0,1), ARMV4_5_STR(1, 0));
 
 	/* restore CP15 MMU and Cache settings */
-	arm920t_write_cp15_physical(target, ARM920T_CP15_PHYS_ADDR(0, 0x1, 0), cp15_ctrl_saved);
+	arm920t_write_cp15_physical(target, CP15PHYS_CTRL, cp15_ctrl_saved);
 
 	/* output data to file */
 	fprintf(output, "D TLB content:\n");