Re: [PATCH v6 06/18] hw/arm/allwinner: add CPU Configuration module

["Alex Bennée" <alex.bennee@linaro.org>]

Niek Linnenbank <nieklinnenbank@gmail.com> writes:

> Various Allwinner System on Chip designs contain multiple processors
> that can be configured and reset using the generic CPU Configuration
> module interface. This commit adds support for the Allwinner CPU
> configuration interface which emulates the following features:
>
>  * CPU reset
>  * CPU status
>
> Signed-off-by: Niek Linnenbank <nieklinnenbank@gmail.com>
<snip>
> +
> +/* CPUCFG constants */
> +enum {
> +    CPU_EXCEPTION_LEVEL_ON_RESET = 3, /* EL3 */
> +};
> +
> +static void allwinner_cpucfg_cpu_reset(AwCpuCfgState *s, uint8_t cpu_id)
> +{
> +    int ret;
> +
> +    trace_allwinner_cpucfg_cpu_reset(cpu_id, s->entry_addr);
> +
> +    ret = arm_set_cpu_on(cpu_id, s->entry_addr, 0,
> +                         CPU_EXCEPTION_LEVEL_ON_RESET, false);

According to the arm_set_cpu_on code:

    if (!target_aa64 && arm_feature(&target_cpu->env, ARM_FEATURE_AARCH64)) {
        /*
         * For now we don't support booting an AArch64 CPU in AArch32 mode
         * TODO: We should add this support later
         */
        qemu_log_mask(LOG_UNIMP,
                      "[ARM]%s: Starting AArch64 CPU %" PRId64
                      " in AArch32 mode is not supported yet\n",
                      __func__, cpuid);
        return QEMU_ARM_POWERCTL_INVALID_PARAM;
    }

Do you really want to reboot in aarch32 mode on a reset? If so we should
fix the TODO.

-- 
Alex Bennée