Kernel/Arch/aarch64/Aarch64Asm.h


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/*
 * Copyright (c) 2021, James Mintram <me@jamesrm.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <Kernel/Arch/aarch64/Aarch64Registers.h>

namespace Kernel {

[[noreturn]] inline void halt()
{
    for (;;) {
        asm volatile("wfi");
    }
}

enum class ExceptionLevel : u8 {
    EL0 = 0,
    EL1 = 1,
    EL2 = 2,
    EL3 = 3,
};

inline ExceptionLevel get_current_exception_level()
{
    u64 current_exception_level;

    asm("mrs  %[value], CurrentEL"
        : [value] "=r"(current_exception_level));

    current_exception_level = (current_exception_level >> 2) & 0x3;
    return static_cast<ExceptionLevel>(current_exception_level);
}

}