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>

1 files changed, 38 insertions, 12 deletions

diff --git a/src/target/cortex_a8.c b/src/target/cortex_a8.c
index fc788446..d62740c2 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;