libstrat: revise emummc utility accessors

include/stratosphere.hpp

@@ -17,6 +17,7 @@
 #pragma once
 
 #include "stratosphere/utilities.hpp"
+#include "stratosphere/emummc_utilities.hpp"
 
 #include "stratosphere/scope_guard.hpp"
 

include/stratosphere/emummc_utilities.hpp

@@ -0,0 +1,28 @@
+/*
+ * 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/>.
+ */
+ 
+#pragma once
+#include <switch.h>
+#include <cstdlib>
+
+/* Get whether emummc is active. */
+bool IsEmummc();
+
+/* Get Nintendo redirection path. */
+const char *GetEmummcNintendoDirPath();
+
+/* Get Emummc folderpath, NULL if not file-based. */
+const char *GetEmummcFilePath();

include/stratosphere/utilities.hpp

@@ -118,23 +118,6 @@ static inline bool ShouldBlankProdInfo() {
     return should_blank_prodinfo;
 }
 
-static inline Result GetEmunandConfig(u64 *out) {
-    u64 tmp = 0;
-    Result rc = SmcGetConfig((SplConfigItem)65100, &tmp);
-    if (R_SUCCEEDED(rc)) {
-        *out = tmp;
-    }
-    return rc;
-}
-
-static inline bool IsEmunand() {
-    u64 emunand;
-    if (R_FAILED(GetEmunandConfig(&emunand))) {
-        std::abort();
-    }
-    return emunand != 0;
-}
-
 HosRecursiveMutex &GetSmSessionMutex();
 HosRecursiveMutex &GetSmMitmSessionMutex();
 

source/emummc_utilities.cpp

@@ -0,0 +1,142 @@
+/*
+ * 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 <switch.h>
+#include <stratosphere.hpp>
+
+/* EFS0 */
+static constexpr u32 EmummcStorageMagic = 0x30534645;
+static constexpr size_t EmummcMaxDirLength = 0x7F;
+
+struct EmummcBaseConfig {
+    u32 magic;
+    u32 type;
+    u32 id;
+    u32 fs_version;
+};
+
+struct EmummcPartitionConfig {
+    u64 start_sector;
+};
+
+struct EmummcFileConfig {
+    char path[EmummcMaxDirLength+1];
+};
+
+struct ExoEmummcConfig {
+    EmummcBaseConfig base_cfg;
+    union {
+        EmummcPartitionConfig partition_cfg;
+        EmummcFileConfig file_cfg;
+    };
+    char emu_dir_path[EmummcMaxDirLength+1];
+};
+
+enum EmummcType {
+    EmummcType_Emmc = 0,
+    EmummcType_Sd,
+    EmummcType_SdFile,
+
+    EmummcType_Max,
+};
+
+static bool g_IsEmummc = false;
+static bool g_HasCached = false;
+static Mutex g_Mutex;
+static ExoEmummcConfig g_exo_emummc_config;
+
+static void _CacheValues(void)
+{
+    if (__atomic_load_n(&g_HasCached, __ATOMIC_SEQ_CST))
+        return;
+
+    mutexLock(&g_Mutex);
+
+    if (g_HasCached) {
+        mutexUnlock(&g_Mutex);
+        return;
+    }
+
+    static struct {
+        char file_path[EmummcMaxDirLength+1];
+        char nintendo_path[EmummcMaxDirLength+1];
+    } __attribute__((aligned(0x1000))) paths;
+    
+    {
+        SecmonArgs args = {0};
+        args.X[0] = 0xF0000404; /* smcAmsGetEmunandConfig */
+        args.X[1] = 0; /* NAND */
+        args.X[2] = reinterpret_cast<u64>(&paths); /* path output */
+        if (R_FAILED(svcCallSecureMonitor(&args)) || args.X[0] != 0) {
+            std::abort();
+        }
+        std::memcpy(&g_exo_emummc_config, &args.X[1], sizeof(args) - sizeof(args.X[0]));
+    }
+    
+    const EmummcType emummc_type = static_cast<EmummcType>(g_exo_emummc_config.base_cfg.type);
+    
+/* Ignore format warnings. */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wformat-truncation"
+    switch (emummc_type) {
+        case EmummcType_SdFile:
+            std::snprintf(g_exo_emummc_config.file_cfg.path, sizeof(g_exo_emummc_config.file_cfg.path), "/%s", paths.file_path);
+            break;
+        default:
+            break;
+    }
+    
+    std::snprintf(g_exo_emummc_config.emu_dir_path, sizeof(g_exo_emummc_config.emu_dir_path), "/%s", paths.nintendo_path);
+    
+    g_IsEmummc = g_exo_emummc_config.base_cfg.magic == EmummcStorageMagic && emummc_type != EmummcType_Emmc;
+    
+    /* Default Nintendo redirection path. */
+    if (g_IsEmummc) {
+        if (std::strcmp(g_exo_emummc_config.emu_dir_path, "/") == 0) {
+            std::snprintf(g_exo_emummc_config.emu_dir_path, sizeof(g_exo_emummc_config.emu_dir_path), "/emummc/Nintendo_%04x", g_exo_emummc_config.base_cfg.id);
+        }
+    }
+#pragma GCC diagnostic pop
+
+    __atomic_store_n(&g_HasCached, true, __ATOMIC_SEQ_CST);
+
+    mutexUnlock(&g_Mutex);
+}
+
+
+/* Get whether emummc is active. */
+bool IsEmummc() {
+    _CacheValues();
+    return g_IsEmummc;
+}
+
+/* Get Nintendo redirection path. */
+const char *GetEmummcNintendoDirPath() {
+    _CacheValues();
+    if (!g_IsEmummc) {
+        return nullptr;
+    }
+    return g_exo_emummc_config.emu_dir_path;
+}
+
+/* Get Emummc folderpath, NULL if not file-based. */
+const char *GetEmummcFilePath() {
+    _CacheValues();
+    if (!g_IsEmummc || g_exo_emummc_config.base_cfg.type != EmummcType_SdFile) {
+        return nullptr;
+    }
+    return g_exo_emummc_config.file_cfg.path;
+}