ARMv7-A: use standard ARM core states

We don't want an ARMv7-specific core state enumeration just to
add ThumbEE state.  Update the generic stuff to handle that,
and replace the V7-specific bits with it.

For Cortex-A8:  on debug entry, check both the T and J bits
instead of just the T bit.  When the J bit is set, set the
right state and warn appropriately.

(And while we're at it, move the generic arm struct to the front
of the v7a structure, for somewhat better code generation.)

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

5 files changed, 43 insertions, 31 deletions

diff --git a/src/target/armv4_5.c b/src/target/armv4_5.c
index 6c6f2bf..5e882e6 100644
--- a/src/target/armv4_5.c
+++ b/src/target/armv4_5.c
@@ -227,7 +227,7 @@ enum armv4_5_mode armv4_5_number_to_mode(int number)
 
 char* armv4_5_state_strings[] =
 {
-	"ARM", "Thumb", "Jazelle"
+	"ARM", "Thumb", "Jazelle", "ThumbEE",
 };
 
 static const struct armv4_5_core_reg armv4_5_core_reg_list_arch_info[] =
diff --git a/src/target/armv4_5.h b/src/target/armv4_5.h
index e3d053c..6b1dd76 100644
--- a/src/target/armv4_5.h
+++ b/src/target/armv4_5.h
@@ -52,6 +52,7 @@ typedef enum armv4_5_state
 	ARMV4_5_STATE_ARM,
 	ARMV4_5_STATE_THUMB,
 	ARMV4_5_STATE_JAZELLE,
+	ARM_STATE_THUMB_EE,
 } armv4_5_state_t;
 
 extern char* armv4_5_state_strings[];
diff --git a/src/target/armv7a.c b/src/target/armv7a.c
index 98e3fa3..ea883c1 100644
--- a/src/target/armv7a.c
+++ b/src/target/armv7a.c
@@ -34,11 +34,6 @@
 #include <unistd.h>
 
 
-static const char *armv7a_state_strings[] =
-{
-	"ARM", "Thumb", "Jazelle", "ThumbEE"
-};
-
 static void armv7a_show_fault_registers(struct target *target)
 {
 	uint32_t dfsr, ifsr, dfar, ifar;
@@ -75,7 +70,7 @@ int armv7a_arch_state(struct target *target)
 	LOG_USER("target halted in %s state due to %s, current mode: %s\n"
 			 "cpsr: 0x%8.8" PRIx32 " pc: 0x%8.8" PRIx32 "\n"
 			 "MMU: %s, D-Cache: %s, I-Cache: %s",
-		 armv7a_state_strings[armv7a->core_state],
+		 armv4_5_state_strings[armv4_5->core_state],
 		 Jim_Nvp_value2name_simple(nvp_target_debug_reason,
 				target->debug_reason)->name,
 		 arm_mode_name(armv4_5->core_mode),
diff --git a/src/target/armv7a.h b/src/target/armv7a.h
index f31a7af..635cd40 100644
--- a/src/target/armv7a.h
+++ b/src/target/armv7a.h
@@ -24,15 +24,6 @@
 #include "armv4_5_mmu.h"
 #include "armv4_5_cache.h"
 
-
-typedef enum armv7a_state
-{
-	ARMV7A_STATE_ARM,
-	ARMV7A_STATE_THUMB,
-	ARMV7A_STATE_JAZELLE,
-	ARMV7A_STATE_THUMBEE,
-} armv7a_state_t;
-
 enum
 {
 	ARM_PC  = 15,
@@ -64,9 +55,9 @@ enum
 
 struct armv7a_common
 {
+	struct arm armv4_5_common;
 	int common_magic;
 	struct reg_cache *core_cache;
-	enum armv7a_state core_state;
 
 	/* arm adp debug port */
 	struct swjdp_common swjdp_info;
@@ -78,7 +69,6 @@ struct armv7a_common
 
 	/* Cache and Memory Management Unit */
 	struct armv4_5_mmu_common armv4_5_mmu;
-	struct arm armv4_5_common;
 
 	int (*read_cp15)(struct target *target,
 			uint32_t op1, uint32_t op2,
@@ -107,7 +97,7 @@ struct armv7a_algorithm
 	int common_magic;
 
 	enum armv4_5_mode core_mode;
-	enum armv7a_state core_state;
+	enum armv4_5_state core_state;
 };
 
 struct armv7a_core_reg
diff --git a/src/target/cortex_a8.c b/src/target/cortex_a8.c
index fc78844..d62740c 100644
--- a/src/target/cortex_a8.c
+++ b/src/target/cortex_a8.c
@@ -491,16 +491,21 @@ static int cortex_a8_resume(struct target *target, int current,
 	/* Make sure that the Armv7 gdb thumb fixups does not
 	 * kill the return address
 	 */
-	if (armv7a->core_state == ARMV7A_STATE_ARM)
+	switch (armv4_5->core_state)
 	{
+	case ARMV4_5_STATE_ARM:
 		resume_pc &= 0xFFFFFFFC;
-	}
-	/* When the return address is loaded into PC
-	 * bit 0 must be 1 to stay in Thumb state
-	 */
-	if (armv7a->core_state == ARMV7A_STATE_THUMB)
-	{
+		break;
+	case ARMV4_5_STATE_THUMB:
+	case ARM_STATE_THUMB_EE:
+		/* When the return address is loaded into PC
+		 * bit 0 must be 1 to stay in Thumb state
+		 */
 		resume_pc |= 0x1;
+		break;
+	case ARMV4_5_STATE_JAZELLE:
+		LOG_ERROR("How do I resume into Jazelle state??");
+		return ERROR_FAIL;
 	}
 	LOG_DEBUG("resume pc = 0x%08" PRIx32, resume_pc);
 	buf_set_u32(ARMV4_5_CORE_REG_MODE(armv4_5->core_cache,
@@ -630,9 +635,29 @@ static int cortex_a8_debug_entry(struct target *target)
 	LOG_DEBUG("cpsr: %8.8" PRIx32, cpsr);
 
 	armv4_5->core_mode = cpsr & 0x1F;
-	armv7a->core_state = (cpsr & 0x20)
-			? ARMV7A_STATE_THUMB
-			: ARMV7A_STATE_ARM;
+
+	i = (cpsr >> 5) & 1;	/* T */
+	i |= (cpsr >> 23) & 1;	/* J << 1 */
+	switch (i) {
+	case 0:	/* J = 0, T = 0 */
+		armv4_5->core_state = ARMV4_5_STATE_ARM;
+		break;
+	case 1:	/* J = 0, T = 1 */
+		armv4_5->core_state = ARMV4_5_STATE_THUMB;
+		break;
+	case 2:	/* J = 1, T = 0 */
+		LOG_WARNING("Jazelle state -- not handled");
+		armv4_5->core_state = ARMV4_5_STATE_JAZELLE;
+		break;
+	case 3:	/* J = 1, T = 1 */
+		/* ThumbEE is very much like Thumb, but some of the
+		 * instructions are different.  Single stepping and
+		 * breakpoints need updating...
+		 */
+		LOG_WARNING("ThumbEE -- incomplete support");
+		armv4_5->core_state = ARM_STATE_THUMB_EE;
+		break;
+	}
 
 	/* update cache */
 	reg = armv4_5->core_cache->reg_list + ARMV4_5_CPSR;
@@ -651,7 +676,7 @@ static int cortex_a8_debug_entry(struct target *target)
 	}
 
 	/* Fixup PC Resume Address */
-	if (armv7a->core_state == ARMV7A_STATE_THUMB)
+	if (cpsr & (1 << 5))
 	{
 		// T bit set for Thumb or ThumbEE state
 		regfile[ARM_PC] -= 4;
@@ -775,7 +800,8 @@ static int cortex_a8_step(struct target *target, int current, uint32_t address,
 
 	/* Setup single step breakpoint */
 	stepbreakpoint.address = address;
-	stepbreakpoint.length = (armv7a->core_state == ARMV7A_STATE_THUMB) ? 2 : 4;
+	stepbreakpoint.length = (armv4_5->core_state == ARMV4_5_STATE_THUMB)
+			? 2 : 4;
 	stepbreakpoint.type = BKPT_HARD;
 	stepbreakpoint.set = 0;