Re: [PATCH 08/17] target/avr: Add offset-io cpu property

[Pierrick Bouvier <pierrick.bouvier@linaro.org>]

On 3/23/25 10:37, Richard Henderson wrote:
> Communicate the offset of io within the first page between the
> board, the cpu, and the translator.  So far this is always 0.
> This will be used to optimize memory layout.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/avr/cpu.h       | 2 ++
>   hw/avr/atmega.c        | 2 ++
>   target/avr/cpu.c       | 1 +
>   target/avr/translate.c | 2 ++
>   4 files changed, 7 insertions(+)
> 
> diff --git a/target/avr/cpu.h b/target/avr/cpu.h
> index be27b0152b..0f5e1a53bc 100644
> --- a/target/avr/cpu.h
> +++ b/target/avr/cpu.h
> @@ -148,6 +148,8 @@ struct ArchCPU {
>   
>       /* Initial value of stack pointer */
>       uint32_t init_sp;
> +    /* Offset of the beginning of I/O within the first page. */
> +    uint32_t offset_io;
>   };
>   
>   /**
> diff --git a/hw/avr/atmega.c b/hw/avr/atmega.c
> index f6844bf118..273582b8af 100644
> --- a/hw/avr/atmega.c
> +++ b/hw/avr/atmega.c
> @@ -236,6 +236,8 @@ static void atmega_realize(DeviceState *dev, Error **errp)
>   
>       object_property_set_uint(OBJECT(&s->cpu), "init-sp",
>                                mc->io_size + mc->sram_size - 1, &error_abort);
> +    object_property_set_uint(OBJECT(&s->cpu), "offset-io",
> +                             0, &error_abort);
>   
>       qdev_realize(DEVICE(&s->cpu), NULL, &error_abort);
>       cpudev = DEVICE(&s->cpu);
> diff --git a/target/avr/cpu.c b/target/avr/cpu.c
> index 0b14b36c17..080f6f30d3 100644
> --- a/target/avr/cpu.c
> +++ b/target/avr/cpu.c
> @@ -169,6 +169,7 @@ static void avr_cpu_initfn(Object *obj)
>   
>   static const Property avr_cpu_properties[] = {
>       DEFINE_PROP_UINT32("init-sp", AVRCPU, init_sp, 0),
> +    DEFINE_PROP_UINT32("offset-io", AVRCPU, offset_io, 0),
>   };
>   
>   static ObjectClass *avr_cpu_class_by_name(const char *cpu_model)
> diff --git a/target/avr/translate.c b/target/avr/translate.c
> index 0490936cd5..e9fef1aaad 100644
> --- a/target/avr/translate.c
> +++ b/target/avr/translate.c
> @@ -92,6 +92,7 @@ struct DisasContext {
>   
>       /* Routine used to access memory */
>       int memidx;
> +    uint32_t offset_io;
>   
>       /*
>        * some AVR instructions can make the following instruction to be skipped
> @@ -2664,6 +2665,7 @@ static void avr_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
>       ctx->cs = cs;
>       ctx->env = cpu_env(cs);
>       ctx->npc = ctx->base.pc_first / 2;
> +    ctx->offset_io = env_archcpu(ctx->env)->offset_io;
>   
>       ctx->skip_cond = TCG_COND_NEVER;
>       if (tb_flags & TB_FLAGS_SKIP) {

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>