ARM: add is_arm_mode()

Add a new is_arm_mode() predicate, and use it to replace almost
all calls to current armv4_5_mode_to_number().

Eventually those internal mode numbers should vanish... along
with their siblings in the armv7a.c file.

Remove a handful of superfluous checks ... e.g. the mode number
was just initialized, or (debug entry methods) already validated.

Move one of the macros using internal mode numbers into the only
file which uses that macro.  Make the tables manipulated with
those numbers be read-only and, where possible, static so they're
not confused with part of the generic ARM interface.

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

6 files changed, 39 insertions, 40 deletions

diff --git a/src/target/arm11.c b/src/target/arm11.c
index 5e732758..3a235852 100644
--- a/src/target/arm11.c
+++ b/src/target/arm11.c
@@ -1603,7 +1603,7 @@ static int arm11_run_algorithm(struct target *target,
 	}
 
 	// FIXME
-//	if (armv4_5_mode_to_number(arm11->core_mode)==-1)
+//	if (!is_arm_mode(arm11->core_mode))
 //		return ERROR_FAIL;
 
 	// Save regs
diff --git a/src/target/arm7_9_common.c b/src/target/arm7_9_common.c
index ff95a0cd..37aa0660 100644
--- a/src/target/arm7_9_common.c
+++ b/src/target/arm7_9_common.c
@@ -1242,9 +1242,6 @@ int arm7_9_soft_reset_halt(struct target *target)
 	armv4_5->core_mode = ARMV4_5_MODE_SVC;
 	armv4_5->core_state = ARMV4_5_STATE_ARM;
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
-		return ERROR_FAIL;
-
 	/* reset registers */
 	for (i = 0; i <= 14; i++)
 	{
@@ -1413,7 +1410,7 @@ static int arm7_9_debug_entry(struct target *target)
 
 	armv4_5->core_mode = cpsr & 0x1f;
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode) == -1)
+	if (!is_arm_mode(armv4_5->core_mode))
 	{
 		target->state = TARGET_UNKNOWN;
 		LOG_ERROR("cpsr contains invalid mode value - communication failure");
@@ -1439,9 +1436,6 @@ static int arm7_9_debug_entry(struct target *target)
 	else
 		context[15] -= arm7_9->dbgreq_adjust_pc * ((armv4_5->core_state == ARMV4_5_STATE_ARM) ? 4 : 2);
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
-		return ERROR_FAIL;
-
 	for (i = 0; i <= 15; i++)
 	{
 		LOG_DEBUG("r%i: 0x%8.8" PRIx32 "", i, context[i]);
@@ -1452,9 +1446,6 @@ static int arm7_9_debug_entry(struct target *target)
 
 	LOG_DEBUG("entered debug state at PC 0x%" PRIx32 "", context[15]);
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
-		return ERROR_FAIL;
-
 	/* exceptions other than USR & SYS have a saved program status register */
 	if ((armv4_5->core_mode != ARMV4_5_MODE_USR) && (armv4_5->core_mode != ARMV4_5_MODE_SYS))
 	{
@@ -1506,7 +1497,7 @@ int arm7_9_full_context(struct target *target)
 		return ERROR_TARGET_NOT_HALTED;
 	}
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	/* iterate through processor modes (User, FIQ, IRQ, SVC, ABT, UND)
@@ -1606,7 +1597,7 @@ int arm7_9_restore_context(struct target *target)
 	if (arm7_9->pre_restore_context)
 		arm7_9->pre_restore_context(target);
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	/* iterate through processor modes (User, FIQ, IRQ, SVC, ABT, UND)
@@ -2104,7 +2095,7 @@ int arm7_9_read_core_reg(struct target *target, int num, enum armv4_5_mode mode)
 	struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
 	struct armv4_5_common_s *armv4_5 = &arm7_9->armv4_5_common;
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	enum armv4_5_mode reg_mode = ((struct armv4_5_core_reg*)ARMV4_5_CORE_REG_MODE(armv4_5->core_cache, mode, num).arch_info)->mode;
@@ -2168,7 +2159,7 @@ int arm7_9_write_core_reg(struct target *target, int num, enum armv4_5_mode mode
 	struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
 	struct armv4_5_common_s *armv4_5 = &arm7_9->armv4_5_common;
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	enum armv4_5_mode reg_mode = ((struct armv4_5_core_reg*)ARMV4_5_CORE_REG_MODE(armv4_5->core_cache, mode, num).arch_info)->mode;
@@ -2373,7 +2364,7 @@ int arm7_9_read_memory(struct target *target, uint32_t address, uint32_t size, u
 			break;
 	}
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	for (i = 0; i <= last_reg; i++)
@@ -2556,7 +2547,7 @@ int arm7_9_write_memory(struct target *target, uint32_t address, uint32_t size,
 	buf_set_u32(dbg_ctrl->value, EICE_DBG_CONTROL_DBGACK, 1, 1);
 	embeddedice_store_reg(dbg_ctrl);
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	for (i = 0; i <= last_reg; i++)
diff --git a/src/target/arm920t.c b/src/target/arm920t.c
index e1dcea7a..29f7917d 100644
--- a/src/target/arm920t.c
+++ b/src/target/arm920t.c
@@ -244,7 +244,7 @@ static int arm920t_read_cp15_interpreted(struct target *target,
 	LOG_DEBUG("cp15_opcode: %8.8x, address: %8.8x, value: %8.8x", cp15_opcode, address, *value);
 #endif
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	ARMV4_5_CORE_REG_MODE(armv4_5->core_cache, armv4_5->core_mode, 0).dirty = 1;
@@ -284,7 +284,7 @@ int arm920t_write_cp15_interpreted(struct target *target,
 	LOG_DEBUG("cp15_opcode: %8.8x, value: %8.8x, address: %8.8x", cp15_opcode, value, address);
 #endif
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	ARMV4_5_CORE_REG_MODE(armv4_5->core_cache, armv4_5->core_mode, 0).dirty = 1;
@@ -889,7 +889,7 @@ COMMAND_HANDLER(arm920t_handle_read_cache_command)
 
 	fclose(output);
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	/* mark registers dirty. */
@@ -1172,7 +1172,7 @@ COMMAND_HANDLER(arm920t_handle_read_mmu_command)
 
 	fclose(output);
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	/* mark registers dirty */
diff --git a/src/target/armv4_5.c b/src/target/armv4_5.c
index 6864efbb..d22e0f3a 100644
--- a/src/target/armv4_5.c
+++ b/src/target/armv4_5.c
@@ -36,7 +36,7 @@
 #include "register.h"
 
 
-char* armv4_5_core_reg_list[] =
+static const char *armv4_5_core_reg_list[] =
 {
 	"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r13_usr", "lr_usr", "pc",
 
@@ -101,9 +101,7 @@ static const struct {
 /** Map PSR mode bits to the name of an ARM processor operating mode. */
 const char *arm_mode_name(unsigned psr_mode)
 {
-	unsigned i;
-
-	for (i = 0; i < ARRAY_SIZE(arm_mode_data); i++) {
+	for (unsigned i = 0; i < ARRAY_SIZE(arm_mode_data); i++) {
 		if (arm_mode_data[i].psr == psr_mode)
 			return arm_mode_data[i].name;
 	}
@@ -111,7 +109,17 @@ const char *arm_mode_name(unsigned psr_mode)
 	return "UNRECOGNIZED";
 }
 
-/** Map PSR mode bits to linear number */
+/** Return true iff the parameter denotes a valid ARM processor mode. */
+bool is_arm_mode(unsigned psr_mode)
+{
+	for (unsigned i = 0; i < ARRAY_SIZE(arm_mode_data); i++) {
+		if (arm_mode_data[i].psr == psr_mode)
+			return true;
+	}
+	return false;
+}
+
+/** Map PSR mode bits to linear number indexing armv4_5_core_reg_map */
 int armv4_5_mode_to_number(enum armv4_5_mode mode)
 {
 	switch (mode) {
@@ -137,7 +145,7 @@ int armv4_5_mode_to_number(enum armv4_5_mode mode)
 	}
 }
 
-/** Map linear number to PSR mode bits. */
+/** Map linear number indexing armv4_5_core_reg_map to PSR mode bits. */
 enum armv4_5_mode armv4_5_number_to_mode(int number)
 {
 	switch (number) {
@@ -166,7 +174,7 @@ char* armv4_5_state_strings[] =
 	"ARM", "Thumb", "Jazelle"
 };
 
-struct armv4_5_core_reg armv4_5_core_reg_list_arch_info[] =
+static const struct armv4_5_core_reg armv4_5_core_reg_list_arch_info[] =
 {
 	{0, ARMV4_5_MODE_ANY, NULL, NULL},
 	{1, ARMV4_5_MODE_ANY, NULL, NULL},
@@ -214,7 +222,7 @@ struct armv4_5_core_reg armv4_5_core_reg_list_arch_info[] =
 };
 
 /* map core mode (USR, FIQ, ...) and register number to indizes into the register cache */
-int armv4_5_core_reg_map[7][17] =
+const int armv4_5_core_reg_map[7][17] =
 {
 	{	/* USR */
 		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 31
@@ -383,7 +391,7 @@ struct reg_cache* armv4_5_build_reg_cache(struct target *target, struct arm *arm
 		arch_info[i] = armv4_5_core_reg_list_arch_info[i];
 		arch_info[i].target = target;
 		arch_info[i].armv4_5_common = armv4_5_common;
-		reg_list[i].name = armv4_5_core_reg_list[i];
+		reg_list[i].name = (char *) armv4_5_core_reg_list[i];
 		reg_list[i].size = 32;
 		reg_list[i].value = calloc(1, 4);
 		reg_list[i].dirty = 0;
@@ -415,6 +423,9 @@ int armv4_5_arch_state(struct target *target)
 	return ERROR_OK;
 }
 
+#define ARMV4_5_CORE_REG_MODENUM(cache, mode, num) \
+		cache->reg_list[armv4_5_core_reg_map[mode][num]]
+
 COMMAND_HANDLER(handle_armv4_5_reg_command)
 {
 	char output[128];
@@ -435,7 +446,7 @@ COMMAND_HANDLER(handle_armv4_5_reg_command)
 		return ERROR_OK;
 	}
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	if (!armv4_5->full_context) {
@@ -599,7 +610,7 @@ int armv4_5_get_gdb_reg_list(struct target *target, struct reg **reg_list[], int
 	struct armv4_5_common_s *armv4_5 = target_to_armv4_5(target);
 	int i;
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	*reg_list_size = 26;
@@ -679,7 +690,7 @@ int armv4_5_run_algorithm_inner(struct target *target, int num_mem_params, struc
 		return ERROR_TARGET_NOT_HALTED;
 	}
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
+	if (!is_arm_mode(armv4_5->core_mode))
 		return ERROR_FAIL;
 
 	/* armv5 and later can terminate with BKPT instruction; less overhead */
diff --git a/src/target/armv4_5.h b/src/target/armv4_5.h
index 5b7a5220..81eac476 100644
--- a/src/target/armv4_5.h
+++ b/src/target/armv4_5.h
@@ -42,6 +42,8 @@ typedef enum armv4_5_mode
 } armv4_5_mode_t;
 
 const char *arm_mode_name(unsigned psr_mode);
+bool is_arm_mode(unsigned psr_mode);
+
 int armv4_5_mode_to_number(enum armv4_5_mode mode);
 enum armv4_5_mode armv4_5_number_to_mode(int number);
 
@@ -54,12 +56,10 @@ typedef enum armv4_5_state
 
 extern char* armv4_5_state_strings[];
 
-extern int armv4_5_core_reg_map[7][17];
+extern const int armv4_5_core_reg_map[7][17];
 
 #define ARMV4_5_CORE_REG_MODE(cache, mode, num) \
 		cache->reg_list[armv4_5_core_reg_map[armv4_5_mode_to_number(mode)][num]]
-#define ARMV4_5_CORE_REG_MODENUM(cache, mode, num) \
-		cache->reg_list[armv4_5_core_reg_map[mode][num]]
 
 /* offsets into armv4_5 core register cache */
 enum
diff --git a/src/target/xscale.c b/src/target/xscale.c
index 38928f41..09e68254 100644
--- a/src/target/xscale.c
+++ b/src/target/xscale.c
@@ -954,7 +954,7 @@ static int xscale_debug_entry(struct target *target)
 	LOG_DEBUG("cpsr: 0x%8.8" PRIx32 "", buffer[9]);
 
 	armv4_5->core_mode = buffer[9] & 0x1f;
-	if (armv4_5_mode_to_number(armv4_5->core_mode) == -1)
+	if (!is_arm_mode(armv4_5->core_mode))
 	{
 		target->state = TARGET_UNKNOWN;
 		LOG_ERROR("cpsr contains invalid mode value - communication failure");
@@ -969,9 +969,6 @@ static int xscale_debug_entry(struct target *target)
 		armv4_5->core_state = ARMV4_5_STATE_ARM;
 
 
-	if (armv4_5_mode_to_number(armv4_5->core_mode)==-1)
-		return ERROR_FAIL;
-
 	/* get banked registers, r8 to r14, and spsr if not in USR/SYS mode */
 	if ((armv4_5->core_mode != ARMV4_5_MODE_USR) && (armv4_5->core_mode != ARMV4_5_MODE_SYS))
 	{