Re: [RFC PATCH 2/4] hw/arm/raspi: Replace TARGET_AARCH64 by legacy_binary_is_64bit()

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

On 3/5/25 08:12, Philippe Mathieu-Daudé wrote:
> For legacy ARM binaries, legacy_binary_is_64bit() is
> equivalent of the compile time TARGET_AARCH64 definition.
> 

I'm not sure where this function comes from.

Anyway, to completely replace TARGET_AARCH64, what we want is something 
like: target_is_aarch64(), because all the objects in this file should 
not be enabled for 64 bits targets who are not arm based.

So it's more easy to introduce a specific function *per* target, and 
enable objects on a per need basis. Some will be enabled for all 
targets, some for only one, some for a specific selection.

> Use it as TypeInfo::registerable() callback to dynamically
> add Aarch64 specific types in qemu-system-aarch64 binary,
> removing the need of TARGET_AARCH64 #ifdef'ry.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   hw/arm/bcm2836.c | 6 ++----
>   hw/arm/raspi.c   | 7 +++----
>   2 files changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/arm/bcm2836.c b/hw/arm/bcm2836.c
> index 95e16806fa1..88a32e5fc20 100644
> --- a/hw/arm/bcm2836.c
> +++ b/hw/arm/bcm2836.c
> @@ -12,6 +12,7 @@
>   #include "qemu/osdep.h"
>   #include "qapi/error.h"
>   #include "qemu/module.h"
> +#include "qemu/legacy_binary_info.h"
>   #include "hw/arm/bcm2836.h"
>   #include "hw/arm/raspi_platform.h"
>   #include "hw/sysbus.h"
> @@ -195,7 +196,6 @@ static void bcm2836_class_init(ObjectClass *oc, void *data)
>       dc->realize = bcm2836_realize;
>   };
>   
> -#ifdef TARGET_AARCH64
>   static void bcm2837_class_init(ObjectClass *oc, void *data)
>   {
>       DeviceClass *dc = DEVICE_CLASS(oc);
> @@ -208,7 +208,6 @@ static void bcm2837_class_init(ObjectClass *oc, void *data)
>       bc->clusterid = 0x0;
>       dc->realize = bcm2836_realize;
>   };
> -#endif
>   
>   static const TypeInfo bcm283x_types[] = {
>       {
> @@ -219,12 +218,11 @@ static const TypeInfo bcm283x_types[] = {
>           .name           = TYPE_BCM2836,
>           .parent         = TYPE_BCM283X,
>           .class_init     = bcm2836_class_init,
> -#ifdef TARGET_AARCH64
>       }, {
>           .name           = TYPE_BCM2837,
>           .parent         = TYPE_BCM283X,
> +        .registerable   = legacy_binary_is_64bit,
>           .class_init     = bcm2837_class_init,
> -#endif
>       }, {
>           .name           = TYPE_BCM283X,
>           .parent         = TYPE_BCM283X_BASE,
> diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c
> index dce35ca11aa..f7e647a9cbf 100644
> --- a/hw/arm/raspi.c
> +++ b/hw/arm/raspi.c
> @@ -15,6 +15,7 @@
>   #include "qemu/osdep.h"
>   #include "qemu/units.h"
>   #include "qemu/cutils.h"
> +#include "qemu/legacy_binary_info.h"
>   #include "qapi/error.h"
>   #include "hw/arm/boot.h"
>   #include "hw/arm/bcm2836.h"
> @@ -367,7 +368,6 @@ static void raspi2b_machine_class_init(ObjectClass *oc, void *data)
>       raspi_machine_class_init(mc, rmc->board_rev);
>   };
>   
> -#ifdef TARGET_AARCH64
>   static void raspi3ap_machine_class_init(ObjectClass *oc, void *data)
>   {
>       MachineClass *mc = MACHINE_CLASS(oc);
> @@ -387,7 +387,6 @@ static void raspi3b_machine_class_init(ObjectClass *oc, void *data)
>       rmc->board_rev = 0xa02082;
>       raspi_machine_class_init(mc, rmc->board_rev);
>   };
> -#endif /* TARGET_AARCH64 */
>   
>   static const TypeInfo raspi_machine_types[] = {
>       {
> @@ -402,16 +401,16 @@ static const TypeInfo raspi_machine_types[] = {
>           .name           = MACHINE_TYPE_NAME("raspi2b"),
>           .parent         = TYPE_RASPI_MACHINE,
>           .class_init     = raspi2b_machine_class_init,
> -#ifdef TARGET_AARCH64
>       }, {
>           .name           = MACHINE_TYPE_NAME("raspi3ap"),
>           .parent         = TYPE_RASPI_MACHINE,
> +        .registerable   = legacy_binary_is_64bit,
>           .class_init     = raspi3ap_machine_class_init,
>       }, {
>           .name           = MACHINE_TYPE_NAME("raspi3b"),
>           .parent         = TYPE_RASPI_MACHINE,
> +        .registerable   = legacy_binary_is_64bit,
>           .class_init     = raspi3b_machine_class_init,
> -#endif
>       }, {
>           .name           = TYPE_RASPI_MACHINE,
>           .parent         = TYPE_RASPI_BASE_MACHINE,