Atmosphere/stratosphere/loader/source/ldr_patcher.cpp
2020-03-09 03:10:12 -07:00

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2.2 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 "ldr_patcher.hpp"
namespace ams::ldr {
namespace {
constexpr const char *NsoPatchesDirectory = "exefs_patches";
/* Exefs patches want to prevent modification of header, */
/* and also want to adjust offset relative to mapped location. */
constexpr size_t NsoPatchesProtectedSize = sizeof(NsoHeader);
constexpr size_t NsoPatchesProtectedOffset = sizeof(NsoHeader);
constexpr const char * const LoaderSdMountName = "#amsldr-sdpatch";
static_assert(sizeof(LoaderSdMountName) <= fs::MountNameLengthMax);
os::Mutex g_ldr_sd_lock;
bool g_mounted_sd;
bool EnsureSdCardMounted() {
std::scoped_lock lk(g_ldr_sd_lock);
if (g_mounted_sd) {
return true;
}
if (!cfg::IsSdCardInitialized()) {
return false;
}
if (R_FAILED(fs::MountSdCard(LoaderSdMountName))) {
return false;
}
return (g_mounted_sd = true);
}
}
/* Apply IPS patches. */
void LocateAndApplyIpsPatchesToModule(const u8 *build_id, uintptr_t mapped_nso, size_t mapped_size) {
if (!EnsureSdCardMounted()) {
return;
}
ro::ModuleId module_id;
std::memcpy(&module_id.build_id, build_id, sizeof(module_id.build_id));
ams::patcher::LocateAndApplyIpsPatchesToModule(LoaderSdMountName, NsoPatchesDirectory, NsoPatchesProtectedSize, NsoPatchesProtectedOffset, &module_id, reinterpret_cast<u8 *>(mapped_nso), mapped_size);
}
}