Revert "target: add target->type->has_mmu fn"

This patch introduced a bug preventing flash writes from working
on Cortex-M3 targets like the STM32.  Moreover, it's the wrong
approach for handling no-MMU targets.

The right way to handle no-MMU targets is to provide accessors
for physical addresses, and use them everywhere; and any code
which tries to work with virtual-to-physical mappings should use
a identity mapping (which can be defaulted).

And ... we can tell if a target has an MMU by seeing if it's
got an mmu() method.  No such methood means no MMU.

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

src/target/cortex_m3.c

@@ -56,12 +56,6 @@ extern uint8_t armv7m_gdb_dummy_cpsr_value[];
 extern reg_t armv7m_gdb_dummy_cpsr_reg;
 #endif
 
-static int cortex_m3_has_mmu(struct target_s *target, bool *has_mmu)
-{
-	*has_mmu = false;
-	return ERROR_OK;
-}
-
 static int cortexm3_dap_read_coreregister_u32(swjdp_common_t *swjdp,
 		uint32_t *value, int regnum)
 {
@@ -1998,6 +1992,5 @@ target_type_t cortexm3_target =
 	.register_commands = cortex_m3_register_commands,
 	.target_create = cortex_m3_target_create,
 	.init_target = cortex_m3_init_target,
-	.has_mmu = cortex_m3_has_mmu,
 	.examine = cortex_m3_examine,
 };

src/target/target.c

@@ -496,13 +496,7 @@ static int default_virt2phys(struct target_s *target, uint32_t virtual, uint32_t
 
 static int default_mmu(struct target_s *target, int *enabled)
 {
-	LOG_ERROR("Not implemented.");
+	*enabled = 0;
-	return ERROR_FAIL;
-}
-
-static int default_has_mmu(struct target_s *target, bool *has_mmu)
-{
-	*has_mmu = true;
 	return ERROR_OK;
 }
 
@@ -772,34 +766,16 @@ int target_mcr(struct target_s *target, int cpnum, uint32_t op1, uint32_t op2, u
 }
 
 static int default_read_phys_memory(struct target_s *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer)
-{
-	int retval;
-	bool mmu;
-	retval = target->type->has_mmu(target, &mmu);
-	if (retval != ERROR_OK)
-		return retval;
-	if (mmu)
 {
 	LOG_ERROR("Not implemented");
 	return ERROR_FAIL;
 }
-	return target_read_memory(target, address, size, count, buffer);
-}
 
 static int default_write_phys_memory(struct target_s *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer)
-{
-	int retval;
-	bool mmu;
-	retval = target->type->has_mmu(target, &mmu);
-	if (retval != ERROR_OK)
-		return retval;
-	if (mmu)
 {
 	LOG_ERROR("Not implemented");
 	return ERROR_FAIL;
 }
-	return target_write_memory(target, address, size, count, buffer);
-}
 
 
 int target_init(struct command_context_s *cmd_ctx)
@@ -875,10 +851,6 @@ int target_init(struct command_context_s *cmd_ctx)
 		{
 			target->type->mmu = default_mmu;
 		}
-		if (target->type->has_mmu == NULL)
-		{
-			target->type->has_mmu = default_has_mmu;
-		}
 		target = target->next;
 	}
 

src/target/target_type.h

@@ -199,16 +199,8 @@ struct target_type_s
 	 */
 	int (*write_phys_memory)(struct target_s *target, uint32_t phys_address, uint32_t size, uint32_t count, uint8_t *buffer);
 
-	/* returns true if the mmu is enabled. Default implementation returns error. */
 	int (*mmu)(struct target_s *target, int *enabled);
 
-	/* returns true if the target has an mmu. This can only be
-	determined after the target has been examined.
-	
-	Default implementation returns success and has_mmu==true.
-	*/
-	int (*has_mmu)(struct target_s *target, bool *has_mmu);
-
 	/* Read coprocessor - arm specific. Default implementation returns error. */
 	int (*mrc)(struct target_s *target, int cpnum, uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm, uint32_t *value);