summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--src/target/arm11.c56
1 files changed, 50 insertions, 6 deletions
diff --git a/src/target/arm11.c b/src/target/arm11.c
index f46e424b..94d5fb1b 100644
--- a/src/target/arm11.c
+++ b/src/target/arm11.c
@@ -1200,18 +1200,62 @@ int arm11_step(struct target_s *target, int current, uint32_t address, int handl
int arm11_assert_reset(target_t *target)
{
FNC_INFO;
+ int retval;
- /* FIX! we really should assert srst here, but
- * how do we reset the target into the halted state?
- *
- * Also arm11 behaves "funny" when srst is asserted
- * (as of writing the rules are not understood).
- */
+ arm11_common_t * arm11 = target->arch_info;
+ retval = arm11_check_init(arm11, NULL);
+ if (retval != ERROR_OK)
+ return retval;
+
+ target->state = TARGET_UNKNOWN;
+
+ /* we would very much like to reset into the halted, state,
+ * but resetting and halting is second best... */
if (target->reset_halt)
{
CHECK_RETVAL(target_halt(target));
}
+
+ /* srst is funny. We can not do *anything* else while it's asserted
+ * and it has unkonwn side effects. Make sure no other code runs
+ * meanwhile.
+ *
+ * Code below assumes srst:
+ *
+ * - Causes power-on-reset (but of what parts of the system?). Bug
+ * in arm11?
+ *
+ * - Messes us TAP state without asserting trst.
+ *
+ * - There is another bug in the arm11 core. When you generate an access to
+ * external logic (for example ddr controller via AHB bus) and that block
+ * is not configured (perhaps it is still held in reset), that transaction
+ * will never complete. This will hang arm11 core but it will also hang
+ * JTAG controller. Nothing, short of srst assertion will bring it out of
+ * this.
+ *
+ * Mysteries:
+ *
+ * - What should the PC be after an srst reset when starting in the halted
+ * state?
+ */
+
+ jtag_add_reset(0, 1);
+ jtag_add_reset(0, 0);
+
+ /* How long do we have to wait? */
+ jtag_add_sleep(5000);
+
+ /* un-mess up TAP state */
+ jtag_add_tlr();
+
+ retval = jtag_execute_queue();
+ if (retval != ERROR_OK)
+ {
+ return retval;
+ }
+
return ERROR_OK;
}