cortexm: allow updating demcr from outside

Allow outside accessors to update the demcr. This is useful for updating
the exceptions to catch for handling things like devices that go into
powersave.

Signed-off-by: Sean Cross <sean@xobs.io>

src/target/cortexm.c

@@ -227,6 +227,24 @@ static void cortexm_mem_write(target_s *target, target_addr64_t dest, const void
 	adiv5_mem_write(cortex_ap(target), dest, src, len);
 }
 
+bool target_is_cortexm(const target_s *target)
+{
+	return target == NULL && target->regs_description == cortexm_target_description;
+}
+
+uint32_t cortexm_demcr_read(const target_s *target)
+{
+	const cortexm_priv_s *priv = (const cortexm_priv_s *)target->priv;
+	return priv->demcr;
+}
+
+void cortexm_demcr_write(target_s *target, uint32_t demcr)
+{
+	cortexm_priv_s *priv = (cortexm_priv_s *)target->priv;
+	priv->demcr = demcr;
+	target_mem32_write32(target, CORTEXM_DEMCR, demcr);
+}
+
 bool cortexm_probe(adiv5_access_port_s *ap)
 {
 	target_s *target = target_new();

src/target/cortexm.h

@@ -175,5 +175,8 @@ void cortexm_detach(target_s *target);
 void cortexm_halt_resume(target_s *target, bool step);
 bool cortexm_run_stub(target_s *target, uint32_t loadaddr, uint32_t r0, uint32_t r1, uint32_t r2, uint32_t r3);
 int cortexm_mem_write_aligned(target_s *target, target_addr_t dest, const void *src, size_t len, align_e align);
+uint32_t cortexm_demcr_read(const target_s *target);
+void cortexm_demcr_write(target_s *target, uint32_t demcr);
+bool target_is_cortexm(const target_s *target);
 
 #endif /* TARGET_CORTEXM_H */