[PATCH]: 8f20c8a4c target/cortex_m: make reset robust again [WIP]

[gerrit]

This is an automated email from Gerrit.

"Tomas Vanek <van...@fbl.cz>" just uploaded a new patch set to Gerrit, which 
you can find at https://review.openocd.org/c/openocd/+/6745

-- gerrit

commit 8f20c8a4c04d0539adf3290463237dd8ec788346
Author: Tomas Vanek <van...@fbl.cz>
Date:   Tue Nov 23 10:06:51 2021 +0100

    target/cortex_m: make reset robust again [WIP]
    
    After merging [1] 'reset halt' does not work on not responding Cortex-M.
    
    Relax the examined tests and try to set vector catch VC_CORERESET
    if debug_ap is available.
    
    Try to re-examine after reset deassert.
    
    [1] 98d9f1168cbd (target: reset target examined flag if target::examine() 
fails)
    
    Change-Id: Ie2e018610026180af5997d70231061a275f05c76
    Signed-off-by: Tomas Vanek <van...@fbl.cz>

diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c
index 721cf0a24..ca4110e95 100644
--- a/src/target/cortex_m.c
+++ b/src/target/cortex_m.c
@@ -1401,8 +1401,9 @@ static int cortex_m_assert_reset(struct target *target)
        struct armv7m_common *armv7m = &cortex_m->armv7m;
        enum cortex_m_soft_reset_config reset_config = 
cortex_m->soft_reset_config;
 
-       LOG_DEBUG("target->state: %s",
-               target_state_name(target));
+       LOG_DEBUG("target->state: %s,%s examined",
+               target_state_name(target),
+               target_was_examined(target) ? "" : " not");
 
        enum reset_types jtag_reset_config = jtag_get_reset_config();
 
@@ -1421,14 +1422,14 @@ static int cortex_m_assert_reset(struct target *target)
 
        bool srst_asserted = false;
 
-       if (!target_was_examined(target)) {
+       if (!armv7m->debug_ap) {
                if (jtag_reset_config & RESET_HAS_SRST) {
                        adapter_assert_reset();
                        if (target->reset_halt)
-                               LOG_ERROR("Target not examined, will not halt 
after reset!");
+                               LOG_ERROR("Debug AP not available, will not 
halt after reset!");
                        return ERROR_OK;
                } else {
-                       LOG_ERROR("Target not examined, reset NOT asserted!");
+                       LOG_ERROR("Debug AP not available, reset NOT 
asserted!");
                        return ERROR_FAIL;
                }
        }
@@ -1539,7 +1540,7 @@ static int cortex_m_assert_reset(struct target *target)
        if (retval != ERROR_OK)
                return retval;
 
-       if (target->reset_halt) {
+       if (target->reset_halt && target_was_examined(target)) {
                retval = target_halt(target);
                if (retval != ERROR_OK)
                        return retval;
@@ -1552,8 +1553,9 @@ static int cortex_m_deassert_reset(struct target *target)
 {
        struct armv7m_common *armv7m = &target_to_cm(target)->armv7m;
 
-       LOG_DEBUG("target->state: %s",
-               target_state_name(target));
+       LOG_DEBUG("target->state: %s,%s examined",
+               target_state_name(target),
+               target_was_examined(target) ? "" : " not");
 
        /* deassert reset lines */
        adapter_deassert_reset();
@@ -1562,7 +1564,7 @@ static int cortex_m_deassert_reset(struct target *target)
 
        if ((jtag_reset_config & RESET_HAS_SRST) &&
            !(jtag_reset_config & RESET_SRST_NO_GATING) &&
-               target_was_examined(target)) {
+               armv7m->debug_ap) {
 
                int retval = dap_dp_init_or_reconnect(armv7m->debug_ap->dap);
                if (retval != ERROR_OK) {
@@ -1571,6 +1573,9 @@ static int cortex_m_deassert_reset(struct target *target)
                }
        }
 
+       if (!target_was_examined(target) && !target->defer_examine))
+               target_examine_one(target);
+
        return ERROR_OK;
 }
 

--