Atmosphere/stratosphere/boot/source/boot_boot_reason.cpp

/*
 * Copyright (c) 2018-2019 Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "boot_functions.hpp"
#include "boot_pmic_driver.hpp"
#include "boot_rtc_driver.hpp"

static u32 g_boot_reason = 0;
static bool g_detected_boot_reason = false;

struct BootReasonValue {
    union {
        struct {
            u8 power_intr;
            u8 rtc_intr;
            u8 nv_erc;
            u8 boot_reason;
        };
        u32 value;
    };
};

static u32 MakeBootReason(u32 power_intr, u8 rtc_intr, u8 nv_erc, bool ac_ok) {
    if (power_intr & 0x08) {
        return 2;
    }
    if (rtc_intr & 0x02)  {
        return 3;
    }
    if (power_intr & 0x80) {
        return 1;
    }
    if (rtc_intr & 0x04) {
        if (nv_erc != 0x80 && !Boot::IsRecoveryBoot()) {
            return 4;
        }
    }
    if ((nv_erc & 0x40) && ac_ok) {
        return 1;
    }
    return 0;
}

void Boot::DetectBootReason() {
    u8 power_intr;
    u8 rtc_intr;
    u8 rtc_intr_m;
    u8 nv_erc;
    bool ac_ok;

    /* Get values from PMIC. */
    {
        PmicDriver pmic_driver;
        if (R_FAILED(pmic_driver.GetPowerIntr(&power_intr))) {
            std::abort();
        }
        if (R_FAILED(pmic_driver.GetNvErc(&nv_erc))) {
            std::abort();
        }
        if (R_FAILED(pmic_driver.GetAcOk(&ac_ok))) {
            std::abort();
        }
    }

    /* Get values from RTC. */
    {
        RtcDriver rtc_driver;
        if (R_FAILED(rtc_driver.GetRtcIntr(&rtc_intr))) {
            std::abort();
        }
        if (R_FAILED(rtc_driver.GetRtcIntrM(&rtc_intr_m))) {
            std::abort();
        }
    }

    /* Set global derived boot reason. */
    g_boot_reason = MakeBootReason(power_intr, rtc_intr & ~rtc_intr_m, nv_erc, ac_ok);

    /* Set boot reason for SPL. */
    if (GetRuntimeFirmwareVersion() >= FirmwareVersion_300) {
        BootReasonValue boot_reason_value;
        boot_reason_value.power_intr = power_intr;
        boot_reason_value.rtc_intr = rtc_intr & ~rtc_intr_m;
        boot_reason_value.nv_erc = nv_erc;
        boot_reason_value.boot_reason = g_boot_reason;
        if (R_FAILED(splSetBootReason(boot_reason_value.value))) {
            std::abort();
        }
    }

    g_detected_boot_reason = true;
}

u32 Boot::GetBootReason() {
    if (!g_detected_boot_reason) {
        std::abort();
    }

    return g_boot_reason;
}