boot: implement CheckClock

stratosphere/boot/source/boot_check_clock.cpp

@@ -0,0 +1,48 @@
+/*
+ * 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 "boot_functions.hpp"
+
+static constexpr u32 ExpectedPlluDivP = (1 << 16);
+static constexpr u32 ExpectedPlluDivN = (25 << 8);
+static constexpr u32 ExpectedPlluDivM = (2  << 0);
+static constexpr u32 ExpectedPlluVal  = (ExpectedPlluDivP | ExpectedPlluDivN | ExpectedPlluDivM);
+static constexpr u32 ExpectedPlluMask = 0x1FFFFF;
+
+static constexpr u32 ExpectedUtmipDivN = (25 << 16);
+static constexpr u32 ExpectedUtmipDivM = (1 << 8);
+static constexpr u32 ExpectedUtmipVal  = (ExpectedUtmipDivN | ExpectedUtmipDivM);
+static constexpr u32 ExpectedUtmipMask = 0xFFFF00;
+
+static bool IsUsbClockValid() {
+    u64 _vaddr;
+    if (R_FAILED(svcQueryIoMapping(&_vaddr, 0x60006000ul, 0x1000))) {
+        std::abort();
+    }
+    volatile u32 *car_regs = reinterpret_cast<volatile u32 *>(_vaddr);
+
+    const u32 pllu = car_regs[0xC0 >> 2];
+    const u32 utmip = car_regs[0x480 >> 2];
+    return ((pllu & ExpectedPlluMask) == ExpectedPlluVal) && ((utmip & ExpectedUtmipMask) == ExpectedUtmipVal);
+}
+
+void Boot::CheckClock() {
+    if (!IsUsbClockValid()) {
+        /* Sleep for 1s, then reboot. */
+        svcSleepThread(1'000'000'000ul);
+        Boot::RebootSystem();
+    }
+}

stratosphere/boot/source/boot_functions.hpp

@@ -28,6 +28,11 @@ class Boot {
         /* Functions for actually booting. */
         static void ChangeGpioVoltageTo1_8v();
         static void SetInitialGpioConfiguration();
+        static void CheckClock();
+
+        /* Power utilities. */
+        static void RebootSystem();
+        static void ShutdownSystem();
 
         /* Register Utilities. */
         static u32 ReadPmcRegister(u32 phys_addr);

stratosphere/boot/source/boot_main.cpp

@@ -116,7 +116,8 @@ int main(int argc, char **argv)
     /* Setup GPIO. */
     Boot::SetInitialGpioConfiguration();
     
-    /* TODO: CheckClock(); */
+    /* Check USB PLL/UTMIP clock. */
+    Boot::CheckClock();
     
     /* TODO: DetectBootReason(); */
     

stratosphere/boot/source/boot_reboot_manager.cpp

@@ -17,6 +17,7 @@
 #include <switch.h>
 #include <stratosphere.hpp>
 #include <strings.h>
+#include "boot_functions.hpp"
 #include "boot_reboot_manager.hpp"
 #include "fusee-primary_bin.h"
 
@@ -66,3 +67,9 @@ void BootRebootManager::RebootForFatalError(AtmosphereFatalErrorContext *ctx) {
 
     RebootToIramPayload();
 }
+
+void Boot::RebootSystem() {
+    if (R_FAILED(BootRebootManager::PerformReboot())) {
+        std::abort();
+    }
+}