Atmosphere-libs/libmesosphere/source/board/nintendo/switch/kern_k_system_control.cpp

94 lines
3.5 KiB
C++

/*
* Copyright (c) 2018-2020 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 <mesosphere.hpp>
#include "kern_secure_monitor.hpp"
namespace ams::kern {
namespace {
ALWAYS_INLINE size_t GetRealMemorySizeForInit() {
/* TODO: Move this into a header for the MC in general. */
constexpr u32 MemoryControllerConfigurationRegister = 0x70019050;
u32 config_value;
MESOSPHERE_ABORT_UNLESS(smc::init::ReadWriteRegister(&config_value, MemoryControllerConfigurationRegister, 0, 0));
return static_cast<size_t>(config_value & 0x3FFF) << 20;
}
ALWAYS_INLINE util::BitPack32 GetKernelConfigurationForInit() {
u64 value = 0;
smc::init::GetConfig(&value, 1, smc::ConfigItem::KernelConfiguration);
return util::BitPack32{static_cast<u32>(value)};
}
ALWAYS_INLINE u64 GenerateRandomU64ForInit() {
u64 value;
smc::init::GenerateRandomBytes(&value, sizeof(value));
return value;
}
ALWAYS_INLINE size_t GetIntendedMemorySizeForInit() {
switch (GetKernelConfigurationForInit().Get<smc::KernelConfiguration::MemorySize>()) {
case smc::MemorySize_4GB:
default: /* All invalid modes should go to 4GB. */
return 4_GB;
case smc::MemorySize_6GB:
return 6_GB;
case smc::MemorySize_8GB:
return 8_GB;
}
}
}
/* Initialization. */
KPhysicalAddress KSystemControl::Init::GetKernelPhysicalBaseAddress(uintptr_t base_address) {
const size_t real_dram_size = GetRealMemorySizeForInit();
const size_t intended_dram_size = GetIntendedMemorySizeForInit();
if (intended_dram_size * 2 < real_dram_size) {
return base_address;
} else {
return base_address + ((real_dram_size - intended_dram_size) / 2);
}
}
bool KSystemControl::Init::ShouldIncreaseThreadResourceLimit() {
return GetKernelConfigurationForInit().Get<smc::KernelConfiguration::IncreaseThreadResourceLimit>();
}
/* Randomness for Initialization. */
void KSystemControl::Init::GenerateRandomBytes(void *dst, size_t size) {
MESOSPHERE_ABORT_UNLESS(size <= 0x38);
smc::init::GenerateRandomBytes(dst, size);
}
u64 KSystemControl::Init::GenerateRandomRange(u64 min, u64 max) {
const u64 range_size = ((max + 1) - min);
const u64 effective_max = (std::numeric_limits<u64>::max() / range_size) * range_size;
while (true) {
if (const u64 rnd = GenerateRandomU64ForInit(); rnd < effective_max) {
return min + (rnd % range_size);
}
}
}
void KSystemControl::StopSystem() {
/* Display a panic screen via exosphere. */
smc::Panic(0xF00);
while (true) { /* ... */ }
}
}