Re: [PATCH 2/5] target/riscv/tcg/debug.c: add Debug 1.0 'pending' bit

On Wed, 2026-08-05 at 15:25 -0300, Daniel Henrique Barboza wrote:
> We need to set the 'pending' bit when 'count' reaches 0, clearing it
> right
> after the trigger fires.
> 
> This is 1.0 exclusive behavior so no changes are needed when running
> Debug
> 0.13.
> 
> Signed-off-by: Daniel Henrique Barboza
> <[email protected]>

Reviewed-by: Alistair Francis <[email protected]>

Alistair

> ---
>  target/riscv/tcg/debug.c | 33 +++++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/target/riscv/tcg/debug.c b/target/riscv/tcg/debug.c
> index 3c0fe70101..2191928761 100644
> --- a/target/riscv/tcg/debug.c
> +++ b/target/riscv/tcg/debug.c
> @@ -77,6 +77,11 @@ static int access_size[SIZE_NUM] = {
>      [6 ... 15] = -1,
>  };
>  
> +static bool debug_trigger_version_1_0(CPURISCVState *env)
> +{
> +    return riscv_cpu_cfg(env)->ext_sdtrig;
> +}
> +
>  static inline target_ulong extract_trigger_type(CPURISCVState *env,
>                                                  target_ulong tdata1)
>  {
> @@ -684,6 +689,17 @@ itrigger_set_count(CPURISCVState *env, int
> index, int value)
>                                     ITRIGGER_COUNT, value);
>  }
>  
> +static inline void
> +itrigger_set_pending(CPURISCVState *env, int index, int val)
> +{
> +    if (!debug_trigger_version_1_0(env)) {
> +        return;
> +    }
> +
> +    env->tdata1[index] = set_field(env->tdata1[index],
> +                                   ITRIGGER_PENDING, val);
> +}
> +
>  static bool check_itrigger_priv(CPURISCVState *env, int index)
>  {
>      target_ulong tdata1 = env->tdata1[index];
> @@ -735,8 +751,25 @@ void helper_itrigger_match(CPURISCVState *env)
>          }
>          itrigger_set_count(env, i, count--);
>          if (!count) {
> +            /*
> +             * From the 1.0 spec: "When pending is set, the trigger
> +             * fires just before any further instructions are
> executed
> +             * in a mode where the trigger is enabled. As the
> trigger
> +             * fires, pending is cleared."
> +             *
> +             * And: "This bit becomes set when count is decremented
> +             * from 1 to 0. It is cleared when the trigger fires,
> +             * which will happen just before executing the next
> +             * instruction in one of the enabled modes".
> +             *
> +             * Note that itrigger_set_pending() is a no-op if we're
> +             * running debug 0.13.
> +             */
> +            itrigger_set_pending(env, i, 1);
> +
>              env->itrigger_enabled = riscv_itrigger_enabled(env);
>              do_trigger_action(env, i);
> +            itrigger_set_pending(env, i, 0);
>          }
>      }
>  }