target/cortex_m: do not use VECTRESET on Cortex-M0, M0+ and M1

[openocd.git] / src / target / cortex_m.c

diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c
index 07fea51374c1b2475b7810b904c4aee728bc1bd1..bb8c06d0f6dcdbb9c6e8e979d4bc8ebcc2a48159 100644 (file)
--- a/src/target/cortex_m.c
+++ b/src/target/cortex_m.c
@@ -1041,10 +1041,18 @@ static int cortex_m_assert_reset(struct target *target)
                retval = ERROR_OK;
        } else {
                /* Use a standard Cortex-M3 software reset mechanism.
-                * We default to using VECRESET as it is supported on all current cores.
+                * We default to using VECRESET as it is supported on all current cores
+                * (except Cortex-M0, M0+ and M1 which support SYSRESETREQ only!)
                 * This has the disadvantage of not resetting the peripherals, so a
                 * reset-init event handler is needed to perform any peripheral resets.
                 */
+               if (!cortex_m->vectreset_supported
+                               && reset_config == CORTEX_M_RESET_VECTRESET) {
+                       reset_config = CORTEX_M_RESET_SYSRESETREQ;
+                       LOG_WARNING("VECTRESET is not supported on this Cortex-M core, using SYSRESETREQ instead.");
+                       LOG_WARNING("Set 'cortex_m reset_config sysresetreq'.");
+               }
+
                LOG_DEBUG("Using Cortex-M %s", (reset_config == CORTEX_M_RESET_SYSRESETREQ)
                        ? "SYSRESETREQ" : "VECTRESET");
 
@@ -2027,6 +2035,9 @@ int cortex_m_examine(struct target *target)
                }
                LOG_DEBUG("cpuid: 0x%8.8" PRIx32 "", cpuid);
 
+               /* VECTRESET is not supported on Cortex-M0, M0+ and M1 */
+               cortex_m->vectreset_supported = i > 1;
+
                if (i == 4) {
                        target_read_u32(target, MVFR0, &mvfr0);
                        target_read_u32(target, MVFR1, &mvfr1);
@@ -2418,8 +2429,14 @@ COMMAND_HANDLER(handle_cortex_m_reset_config_command)
        if (CMD_ARGC > 0) {
                if (strcmp(*CMD_ARGV, "sysresetreq") == 0)
                        cortex_m->soft_reset_config = CORTEX_M_RESET_SYSRESETREQ;
-               else if (strcmp(*CMD_ARGV, "vectreset") == 0)
-                       cortex_m->soft_reset_config = CORTEX_M_RESET_VECTRESET;
+
+               else if (strcmp(*CMD_ARGV, "vectreset") == 0) {
+                       if (target_was_examined(target)
+                                       && !cortex_m->vectreset_supported)
+                               LOG_WARNING("VECTRESET is not supported on your Cortex-M core!");
+                       else
+                               cortex_m->soft_reset_config = CORTEX_M_RESET_VECTRESET;
+               }
        }
 
        switch (cortex_m->soft_reset_config) {