Re: [PATCH 05/10] meson: Introduce target-specific Kconfig

[Philippe Mathieu-Daudé]

On 1/31/21 12:13 PM, Philippe Mathieu-Daudé wrote:
> Add a target-specific Kconfig.
> 
> Target foo now has CONFIG_FOO defined.
> 
> Two architecture have a particularity, ARM and MIPS:
> their 64-bit version include the 32-bit subset.
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
...

> diff --git a/meson.build b/meson.build
> index f00b7754fd4..a2dda0ce95e 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1322,7 +1322,8 @@
>        command: [minikconf,
>                  get_option('default_devices') ? '--defconfig' : 
> '--allnoconfig',
>                  config_devices_mak, '@DEPFILE@', '@INPUT@',
> -                host_kconfig, accel_kconfig])
> +                host_kconfig, accel_kconfig,
> +                'CONFIG_' + config_target['TARGET_ARCH'].to_upper() + '=y'])
>  
>      config_devices_data = configuration_data()
>      config_devices = keyval.load(config_devices_mak)
> diff --git a/Kconfig b/Kconfig
> index bf694c42afe..c01e261e4e9 100644
> --- a/Kconfig
> +++ b/Kconfig
> @@ -1,4 +1,5 @@
>  source Kconfig.host
>  source backends/Kconfig
>  source accel/Kconfig
> +source target/Kconfig
>  source hw/Kconfig
> diff --git a/target/Kconfig b/target/Kconfig
> new file mode 100644
> index 00000000000..a6f719f223a
> --- /dev/null
> +++ b/target/Kconfig
> @@ -0,0 +1,23 @@
> +source alpha/Kconfig
> +source arm/Kconfig
> +source avr/Kconfig
> +source cris/Kconfig
> +source hppa/Kconfig
> +source i386/Kconfig
> +source lm32/Kconfig
> +source m68k/Kconfig
> +source microblaze/Kconfig
> +source mips/Kconfig
> +source moxie/Kconfig
> +source nios2/Kconfig
> +source openrisc/Kconfig
> +source ppc/Kconfig
> +source riscv/Kconfig
> +source rx/Kconfig
> +source s390x/Kconfig
> +source sh4/Kconfig
> +source sparc/Kconfig
> +source tilegx/Kconfig
> +source tricore/Kconfig
> +source unicore32/Kconfig
> +source xtensa/Kconfig
> diff --git a/target/arm/Kconfig b/target/arm/Kconfig
> new file mode 100644
> index 00000000000..3f3394a22b2
> --- /dev/null
> +++ b/target/arm/Kconfig
> @@ -0,0 +1,6 @@
> +config ARM
> +    bool
> +
> +config AARCH64
> +    bool
> +    select ARM

This isn't correct yet, as Kconfig is primarly designed for devices,
and per docs/devel/kconfig.rst:

  "devices are usually ``default y`` if and only if they have at
   least one ``depends on``;"

So having one machine "depends on AARCH64" selects AARCH64 on ARM :/
I'll see if explicit each arch as 'default n' helps...