exosphere: Add support for AMS SMC extensions

exosphere/src/smc_ams.c

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2018 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 <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "utils.h"
+#include "smc_api.h"
+#include "smc_ams.h"
+
+uint32_t ams_iram_copy(smc_args_t *args) {
+    /* TODO: Implement a DRAM <-> IRAM copy of up to one page here. */
+    /* This operation is necessary to implement reboot-to-payload. */
+    /* args->X[1] = DRAM address (translated by kernel). */
+    /* args->X[2] = IRAM address. */
+    /* args->X[3] = size (must be <= 0x1000). */
+    /* args->X[4] = 0 for read, 1 for write. */
+    return 2;
+}

exosphere/src/smc_ams.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2018 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/>.
+ */
+ 
+#ifndef EXOSPHERE_SMC_AMS_H
+#define EXOSPHERE_SMC_AMS_H
+
+#include "smc_api.h"
+
+uint32_t ams_iram_copy(smc_args_t *args);
+
+#endif

exosphere/src/smc_api.c

@@ -31,6 +31,7 @@
 #include "sealedkeys.h"
 #include "smc_api.h"
 #include "smc_user.h"
+#include "smc_ams.h"
 #include "se.h"
 #include "userpage.h"
 #include "titlekey.h"
@@ -40,6 +41,8 @@
 #define SMC_USER_HANDLERS 0x13
 #define SMC_PRIV_HANDLERS 0x9
 
+#define SMC_AMS_HANDLERS 0x2
+
 #define DEBUG_LOG_SMCS 0
 #define DEBUG_PANIC_ON_FAILURE 0
 
@@ -77,6 +80,9 @@ uint32_t smc_panic(smc_args_t *args);
 uint32_t smc_configure_carveout(smc_args_t *args);
 uint32_t smc_read_write_register(smc_args_t *args);
 
+/* Atmosphere SMC prototypes */
+uint32_t smc_ams_iram_copy(smc_args_t *args);
+
 typedef struct {
     uint32_t id;
     uint32_t (*handler)(smc_args_t *args);
@@ -121,7 +127,13 @@ static smc_table_entry_t g_smc_priv_table[SMC_PRIV_HANDLERS] = {
     {0xC3000008, smc_read_write_register}
 };
 
-static smc_table_t g_smc_tables[2] = {
+/* This is a table used for atmosphere-specific SMCs. */
+static smc_table_entry_t g_smc_ams_table[SMC_AMS_HANDLERS] = {
+    {0, NULL},
+    {0xF0000201, smc_ams_iram_copy},
+};
+
+static smc_table_t g_smc_tables[SMC_HANDLER_COUNT + 1] = {
     { /* SMC_HANDLER_USER */
         g_smc_user_table,
         SMC_USER_HANDLERS
@@ -129,6 +141,10 @@ static smc_table_t g_smc_tables[2] = {
     { /* SMC_HANDLER_PRIV */
         g_smc_priv_table,
         SMC_PRIV_HANDLERS
+    },
+    { /* SMC_HANDLER_AMS */
+        g_smc_ams_table,
+        SMC_AMS_HANDLERS
     }
 };
 
@@ -228,20 +244,26 @@ void clear_smc_callback(uint64_t key) {
 _Atomic uint64_t num_smcs_called = 0;
 
 void call_smc_handler(uint32_t handler_id, smc_args_t *args) {
-    unsigned char smc_id;
+    unsigned char smc_id, call_range;
     unsigned int result;
     unsigned int (*smc_handler)(smc_args_t *args);
     
     /* Validate top-level handler. */
-    if (handler_id != SMC_HANDLER_USER && handler_id != SMC_HANDLER_PRIV) {
+    if (handler_id >= SMC_HANDLER_COUNT) {
         generic_panic();
     }
 
-    /* Validate core is appropriate for handler. */
-    if (handler_id == SMC_HANDLER_USER && get_core_id() != 3) {
+    /* If user-handler, detect if talking to Atmosphere/validate calling core. */
+    if (handler_id == SMC_HANDLER_USER) {
+        if ((call_range = (unsigned char)((args->X[0] >> 24) & 0x3F)) == SMC_CALL_RANGE_TRUSTED_APP) {
+            /* Nintendo's SMCs are all OEM-specific. */
+            /* Pending a reason not to, we will treat Trusted Application SMCs as intended to talk to Atmosphere. */
+            handler_id = SMC_HANDLER_AMS;
+        } else if (get_core_id() != 3) {
             /* USER SMCs must be called via svcCallSecureMonitor on core 3 (where spl runs) */
             generic_panic();
         }
+    }
 
     /* Validate sub-handler index */
     if ((smc_id = (unsigned char)args->X[0]) >= g_smc_tables[handler_id].num_handlers) {
@@ -683,3 +705,7 @@ uint32_t smc_panic(smc_args_t *args) {
     uint32_t color = ((args->X[1] & 0xF) << 8) | ((args->X[1] & 0xF0)) | ((args->X[1] & 0xF00) >> 8);
     panic((color << 20) | 0x40);
 }
+
+uint32_t smc_ams_iram_copy(smc_args_t *args) {
+    return smc_wrapper_sync(args, ams_iram_copy);
+}

exosphere/src/smc_api.h

@@ -21,6 +21,17 @@
 
 #define SMC_HANDLER_USER  0
 #define SMC_HANDLER_PRIV  1
+#define SMC_HANDLER_COUNT 2
+
+#define SMC_HANDLER_AMS  (SMC_HANDLER_COUNT)
+
+#define SMC_CALL_RANGE_ARM_ARCH    0
+#define SMC_CALL_RANGE_CPU         1
+#define SMC_CALL_RANGE_SIP         2
+#define SMC_CALL_RANGE_OEM         3
+#define SMC_CALL_RANGE_STANDARD    4
+
+#define SMC_CALL_RANGE_TRUSTED_APP 0x30
 
 typedef struct {
     uint64_t X[8];