aarch64: add 'maskisr' command

Allow to configure ISR masking during single-step and add
handling for stepping over WFI with ISR masked.

Change-Id: I7918be7bcda6a1d9badac44fc36c59b52f662fef
Signed-off-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
Reviewed-on: http://openocd.zylin.com/4023
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

diff --git a/doc/openocd.texi b/doc/openocd.texi
index 431f11cb2be4a00f07c7d78f45d1a172a23abcd6..483b27b7f1c2145e1c3ef28aae5310724565dfc4 100644 (file)
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -8418,6 +8418,11 @@ halting or resuming of all cores in the group. The command @code{target smp} def
 group. With SMP handling disabled, all targets need to be treated individually.
 @end deffn
 
+@deffn Command {aarch64 maskisr} [@option{on}|@option{off}]
+Selects whether interrupts will be processed when single stepping. The default configuration is
+@option{on}.
+@end deffn
+
 @section Intel Architecture
 
 Intel Quark X10xx is the first product in the Quark family of SoCs. It is an IA-32

diff --git a/src/target/aarch64.c b/src/target/aarch64.c
index b18a12a4c6156329c664dd20f09cf89a8f328120..f1ce91459dd69665a78cc2d1f1c468a0d069c984 100644 (file)
--- a/src/target/aarch64.c
+++ b/src/target/aarch64.c
@@ -1049,6 +1049,7 @@ static int aarch64_step(struct target *target, int current, target_addr_t addres
        int handle_breakpoints)
 {
        struct armv8_common *armv8 = target_to_armv8(target);
+       struct aarch64_common *aarch64 = target_to_aarch64(target);
        int saved_retval = ERROR_OK;
        int retval;
        uint32_t edecr;
@@ -1069,7 +1070,7 @@ static int aarch64_step(struct target *target, int current, target_addr_t addres
                                armv8->debug_base + CPUV8_DBG_EDECR, (edecr|0x4));
        }
        /* disable interrupts while stepping */
-       if (retval == ERROR_OK)
+       if (retval == ERROR_OK && aarch64->isrmasking_mode == AARCH64_ISRMASK_ON)
                retval = aarch64_set_dscr_bits(target, 0x3 << 22, 0x3 << 22);
        /* bail out if stepping setup has failed */
        if (retval != ERROR_OK)
@@ -1113,7 +1114,7 @@ static int aarch64_step(struct target *target, int current, target_addr_t addres
                if (retval != ERROR_OK || stepped)
                        break;
 
-               if (timeval_ms() > then + 1000) {
+               if (timeval_ms() > then + 100) {
                        LOG_ERROR("timeout waiting for target %s halt after step",
                                        target_name(target));
                        retval = ERROR_TARGET_TIMEOUT;
@@ -1121,8 +1122,14 @@ static int aarch64_step(struct target *target, int current, target_addr_t addres
                }
        }
 
+       /*
+        * At least on one SoC (Renesas R8A7795) stepping over a WFI instruction
+        * causes a timeout. The core takes the step but doesn't complete it and so
+        * debug state is never entered. However, you can manually halt the core
+        * as an external debug even is also a WFI wakeup event.
+        */
        if (retval == ERROR_TARGET_TIMEOUT)
-               saved_retval = retval;
+               saved_retval = aarch64_halt_one(target, HALT_SYNC);
 
        /* restore EDECR */
        retval = mem_ap_write_atomic_u32(armv8->debug_ap,
@@ -1131,9 +1138,11 @@ static int aarch64_step(struct target *target, int current, target_addr_t addres
                return retval;
 
        /* restore interrupts */
-       retval = aarch64_set_dscr_bits(target, 0x3 << 22, 0);
-       if (retval != ERROR_OK)
-               return ERROR_OK;
+       if (aarch64->isrmasking_mode == AARCH64_ISRMASK_ON) {
+               retval = aarch64_set_dscr_bits(target, 0x3 << 22, 0);
+               if (retval != ERROR_OK)
+                       return ERROR_OK;
+       }
 
        if (saved_retval != ERROR_OK)
                return saved_retval;
@@ -2303,9 +2312,9 @@ static int aarch64_examine_first(struct target *target)
 
        LOG_DEBUG("Configured %i hw breakpoints", aarch64->brp_num);
 
-       target->state = TARGET_RUNNING;
+       target->state = TARGET_UNKNOWN;
        target->debug_reason = DBG_REASON_NOTHALTED;
-
+       aarch64->isrmasking_mode = AARCH64_ISRMASK_ON;
        target_set_examined(target);
        return ERROR_OK;
 }
@@ -2443,6 +2452,34 @@ COMMAND_HANDLER(aarch64_handle_smp_on_command)
        return ERROR_OK;
 }
 
+COMMAND_HANDLER(aarch64_mask_interrupts_command)
+{
+       struct target *target = get_current_target(CMD_CTX);
+       struct aarch64_common *aarch64 = target_to_aarch64(target);
+
+       static const Jim_Nvp nvp_maskisr_modes[] = {
+               { .name = "off", .value = AARCH64_ISRMASK_OFF },
+               { .name = "on", .value = AARCH64_ISRMASK_ON },
+               { .name = NULL, .value = -1 },
+       };
+       const Jim_Nvp *n;
+
+       if (CMD_ARGC > 0) {
+               n = Jim_Nvp_name2value_simple(nvp_maskisr_modes, CMD_ARGV[0]);
+               if (n->name == NULL) {
+                       LOG_ERROR("Unknown parameter: %s - should be off or on", CMD_ARGV[0]);
+                       return ERROR_COMMAND_SYNTAX_ERROR;
+               }
+
+               aarch64->isrmasking_mode = n->value;
+       }
+
+       n = Jim_Nvp_value2name_simple(nvp_maskisr_modes, aarch64->isrmasking_mode);
+       command_print(CMD_CTX, "aarch64 interrupt mask %s", n->name);
+
+       return ERROR_OK;
+}
+
 static const struct command_registration aarch64_exec_command_handlers[] = {
        {
                .name = "cache_info",
@@ -2471,6 +2508,13 @@ static const struct command_registration aarch64_exec_command_handlers[] = {
                .help = "Restart smp handling",
                .usage = "",
        },
+       {
+               .name = "maskisr",
+               .handler = aarch64_mask_interrupts_command,
+               .mode = COMMAND_ANY,
+               .help = "mask aarch64 interrupts during single-step",
+               .usage = "['on'|'off']",
+       },
 
        COMMAND_REGISTRATION_DONE
 };

diff --git a/src/target/aarch64.h b/src/target/aarch64.h
index c9ec02dbbf7c8b2f7324d2abb6172341d13705fd..d7886a3d7697f6ad27e0edf7cd1fcfc456a9ebd8 100644 (file)
--- a/src/target/aarch64.h
+++ b/src/target/aarch64.h
@@ -36,6 +36,11 @@
 
 #define AARCH64_PADDRDBG_CPU_SHIFT 13
 
+enum aarch64_isrmasking_mode {
+       AARCH64_ISRMASK_OFF,
+       AARCH64_ISRMASK_ON,
+};
+
 struct aarch64_brp {
        int used;
        int type;
@@ -58,6 +63,8 @@ struct aarch64_common {
        struct aarch64_brp *brp_list;
 
        struct armv8_common armv8_common;
+
+       enum aarch64_isrmasking_mode isrmasking_mode;
 };
 
 static inline struct aarch64_common *