Atmosphere/stratosphere/boot/source/boot_pmc_wrapper.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"

static constexpr u32 SmcFunctionId_AtmosphereReadWriteRegister = 0xF0000002;

static constexpr u32 PmcPhysStart = 0x7000E400;
static constexpr u32 PmcPhysEnd = 0x7000EFFF;

static inline bool IsValidPmcAddress(u32 phys_addr) {
    return (phys_addr & 3) == 0 && PmcPhysStart <= phys_addr && phys_addr <= PmcPhysEnd;
}

static inline u32 SmcAtmosphereReadWriteRegister(u32 phys_addr, u32 value, u32 mask) {
    SecmonArgs args;

    args.X[0] = SmcFunctionId_AtmosphereReadWriteRegister;
    args.X[1] = phys_addr;
    args.X[2] = mask;
    args.X[3] = value;
    svcCallSecureMonitor(&args);
    if (args.X[0] != 0) {
        std::abort();
    }

    return static_cast<u32>(args.X[1]);
}

u32 Boot::ReadPmcRegister(u32 phys_addr) {
    if (!IsValidPmcAddress(phys_addr)) {
        std::abort();
    }

    return SmcAtmosphereReadWriteRegister(phys_addr, 0, 0);
}

void Boot::WritePmcRegister(u32 phys_addr, u32 value, u32 mask) {
    if (!IsValidPmcAddress(phys_addr)) {
        std::abort();
    }

    SmcAtmosphereReadWriteRegister(phys_addr, value, mask);
}