Re: [PATCH 1/2] hw/arm/stm32f405: correctly describe the memory layout

[Philippe Mathieu-Daudé]

Hi Felipe,

On 18/12/22 08:12, Felipe Balbi wrote:
> STM32F405 has 128K of SRAM and another 64K of CCM (Core-coupled
> Memory) at a different base address. Correctly describe the memory
> layout to give existing FW images have a chance to run unmodified.
>
> Signed-off-by: Felipe Balbi <balbi@kernel.org>
> ---
>   hw/arm/stm32f405_soc.c         | 8 ++++++++
>   include/hw/arm/stm32f405_soc.h | 5 ++++-
>   2 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/hw/arm/stm32f405_soc.c b/hw/arm/stm32f405_soc.c
> index c07947d9f8b1..cef23d7ee41a 100644
> --- a/hw/arm/stm32f405_soc.c
> +++ b/hw/arm/stm32f405_soc.c
> @@ -139,6 +139,14 @@ static void stm32f405_soc_realize(DeviceState *dev_soc, 
> Error **errp)
>       }
>       memory_region_add_subregion(system_memory, SRAM_BASE_ADDRESS, &s->sram);
>   
> +    memory_region_init_ram(&s->ccm, NULL, "STM32F405.ccm", CCM_SIZE,

Including the machine name in the memory description seems a bad
habit from old days. What do you think about renaming as
'core-coupled-memory'?

> +                           &err);
> +    if (err != NULL) {
> +        error_propagate(errp, err);
> +        return;
> +    }
> +    memory_region_add_subregion(system_memory, CCM_BASE_ADDRESS, &s->ccm);
> +
>       armv7m = DEVICE(&s->armv7m);
>       qdev_prop_set_uint32(armv7m, "num-irq", 96);
>       qdev_prop_set_string(armv7m, "cpu-type", s->cpu_type);
> diff --git a/include/hw/arm/stm32f405_soc.h b/include/hw/arm/stm32f405_soc.h
> index 5bb0c8d56979..249ab5434ec7 100644
> --- a/include/hw/arm/stm32f405_soc.h
> +++ b/include/hw/arm/stm32f405_soc.h
> @@ -46,7 +46,9 @@ OBJECT_DECLARE_SIMPLE_TYPE(STM32F405State, STM32F405_SOC)
>   #define FLASH_BASE_ADDRESS 0x08000000
>   #define FLASH_SIZE (1024 * 1024)
>   #define SRAM_BASE_ADDRESS 0x20000000
> -#define SRAM_SIZE (192 * 1024)
> +#define SRAM_SIZE (128 * 1024)
> +#define CCM_BASE_ADDRESS 0x10000000
> +#define CCM_SIZE (64 * 1024)

Since the CCM_SIZE won't be used elsewhere, we can simply use '64 * KiB'
in the memory_region_init_ram() in the source file. Up to the maintainer
:)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>