boot: functional exception handling/rebooting to payload

stratosphere/boot/source/boot_main.cpp

@@ -24,6 +24,7 @@
 #include <stratosphere.hpp>
 
 #include "boot_functions.hpp"
+#include "boot_reboot_manager.hpp"
 
 extern "C" {
     extern u32 __start__;
@@ -50,6 +51,11 @@ void __libnx_exception_handler(ThreadExceptionDump *ctx) {
     StratosphereCrashHandler(ctx);
 }
 
+void __libstratosphere_exception_handler(AtmosphereFatalErrorContext *ctx) {
+    /* We're boot sysmodule, so manually reboot to fatal error. */
+    BootRebootManager::RebootForFatalError(ctx);
+}
+
 void __libnx_initheap(void) {
     void*  addr = nx_inner_heap;
     size_t size = nx_inner_heap_size;

stratosphere/boot/source/boot_reboot_manager.cpp

@@ -0,0 +1,68 @@
+/*
+ * 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>
+#include <strings.h>
+#include "boot_reboot_manager.hpp"
+#include "fusee-primary_bin.h"
+
+static u8 g_work_page[0x1000] __attribute__ ((aligned (0x1000)));
+
+static void ClearIram() {
+    /* Make page FFs. */
+    memset(g_work_page, 0xFF, sizeof(g_work_page));
+
+    /* Overwrite all of IRAM with FFs. */
+    for (size_t ofs = 0; ofs < IRAM_SIZE; ofs += sizeof(g_work_page)) {
+        CopyToIram(IRAM_BASE + ofs, g_work_page, sizeof(g_work_page));
+    }
+}
+
+static void DoRebootToPayload() {
+    /* Ensure clean IRAM state. */
+    ClearIram();
+
+    /* Copy in payload. */
+    for (size_t ofs = 0; ofs < fusee_primary_bin_size; ofs += 0x1000) {
+        std::memcpy(g_work_page, &fusee_primary_bin[ofs], std::min(static_cast<size_t>(fusee_primary_bin_size - ofs), size_t(0x1000)));
+        CopyToIram(IRAM_PAYLOAD_BASE + ofs, g_work_page, 0x1000);
+    }
+
+    RebootToIramPayload();
+}
+
+Result BootRebootManager::PerformReboot() {
+    DoRebootToPayload();
+    return ResultSuccess;
+}
+
+void BootRebootManager::RebootForFatalError(AtmosphereFatalErrorContext *ctx) {
+    /* Ensure clean IRAM state. */
+    ClearIram();
+
+    /* Copy in payload. */
+    for (size_t ofs = 0; ofs < fusee_primary_bin_size; ofs += 0x1000) {
+        std::memcpy(g_work_page, &fusee_primary_bin[ofs], std::min(static_cast<size_t>(fusee_primary_bin_size - ofs), size_t(0x1000)));
+        CopyToIram(IRAM_PAYLOAD_BASE + ofs, g_work_page, 0x1000);
+    }
+
+    std::memset(g_work_page, 0xCC, sizeof(g_work_page));
+    std::memcpy(g_work_page, ctx, sizeof(*ctx));
+    CopyToIram(IRAM_PAYLOAD_BASE + IRAM_PAYLOAD_MAX_SIZE, g_work_page, sizeof(g_work_page));
+
+    RebootToIramPayload();
+}

stratosphere/boot/source/boot_reboot_manager.hpp

@@ -0,0 +1,30 @@
+/*
+ * 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 <stratosphere.hpp>
+
+#define IRAM_BASE             0x40000000ull
+#define IRAM_SIZE             0x40000
+#define IRAM_PAYLOAD_MAX_SIZE 0x2E000
+#define IRAM_PAYLOAD_BASE 0x40010000ull
+
+class BootRebootManager {
+    public:
+        static Result PerformReboot();
+        static void RebootForFatalError(AtmosphereFatalErrorContext *ctx);
+};