Re: [Qemu-devel] [PATCH v1 5/5] hw/arm: Add the Netduino Plus 2

[Peter Maydell]

On Mon, 29 Apr 2019 at 06:39, Alistair Francis <address@hidden> wrote:
>
> Signed-off-by: Alistair Francis <address@hidden>
> ---
>  MAINTAINERS                     |  6 +++
>  default-configs/arm-softmmu.mak |  1 +
>  hw/arm/Kconfig                  |  3 ++
>  hw/arm/Makefile.objs            |  1 +
>  hw/arm/netduinoplus2.c          | 77 +++++++++++++++++++++++++++++++++
>  5 files changed, 88 insertions(+)
>  create mode 100644 hw/arm/netduinoplus2.c
>

> +typedef struct ARMV7MResetArgs {
> +    ARMCPU *cpu;
> +    uint32_t reset_sp;
> +    uint32_t reset_pc;
> +} ARMV7MResetArgs;
> +
> +static void armv7m_reset(void *opaque)
> +{
> +    ARMV7MResetArgs *args = opaque;
> +
> +    cpu_reset(CPU(args->cpu));
> +
> +    args->cpu->env.regs[13] = args->reset_sp & 0xFFFFFFFC;
> +    args->cpu->env.thumb = args->reset_pc & 1;
> +    args->cpu->env.regs[15] = args->reset_pc & ~1;
> +}
> +
> +static void netduinoplus2_init(MachineState *machine)
> +{
> +    DeviceState *dev;
> +    ARMV7MResetArgs reset_args;
> +    uint64_t entry;
> +
> +    dev = qdev_create(NULL, TYPE_STM32F405_SOC);
> +    qdev_prop_set_string(dev, "cpu-type", ARM_CPU_TYPE_NAME("cortex-m4"));
> +    object_property_set_bool(OBJECT(dev), true, "realized", &error_fatal);
> +
> +    armv7m_load_kernel(ARM_CPU(first_cpu), machine->kernel_filename,
> +                       FLASH_SIZE, &entry);
> +
> +    reset_args = (ARMV7MResetArgs) {
> +        .cpu = ARM_CPU(first_cpu),
> +        .reset_pc = entry,
> +        .reset_sp = (SRAM_BASE_ADDRESS + (SRAM_SIZE * 2) / 3),
> +    };
> +    qemu_register_reset(armv7m_reset,
> +                        g_memdup(&reset_args, sizeof(reset_args)));
> +}

Can you explain the purpose of the reset code? None of the other
v7m boards seem to need to do a manual qemu_register_reset().

thanks
-- PMM