From e149b8d50335b647f3c9138551f3f3064b931a1f Mon Sep 17 00:00:00 2001
From: Quantum <thomasmuller336@gmail.com>
Date: Wed, 26 Jan 2022 18:31:40 -0500
Subject: [PATCH] OpenSBI: Added SRST(System Reset) extension

---
 kernel/drivers/opensbi/extensions/srst.cpp    | 28 ++++++++++++++++++
 .../opensbi/include/opensbi/extensions/srst.h | 29 +++++++++++++++++++
 kernel/drivers/opensbi/meson.build            |  3 +-
 3 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 kernel/drivers/opensbi/extensions/srst.cpp
 create mode 100644 kernel/drivers/opensbi/include/opensbi/extensions/srst.h

diff --git a/kernel/drivers/opensbi/extensions/srst.cpp b/kernel/drivers/opensbi/extensions/srst.cpp
new file mode 100644
index 0000000..24970e4
--- /dev/null
+++ b/kernel/drivers/opensbi/extensions/srst.cpp
@@ -0,0 +1,28 @@
+#include "opensbi/extensions/srst.h"
+
+namespace drivers {
+namespace opensbi::srst {
+
+    namespace {
+        enum class ExtensionId {
+            SRST = 0x53525354
+        };
+
+        enum class FunctionId {
+            SYSTEM_RESET
+        };
+    }
+
+    SbiRet system_reset(
+            ResetType reset_type,
+            ResetReason reset_reason) {
+        return ecall(
+            static_cast<sbiword_t>(ExtensionId::SRST),
+            static_cast<sbiword_t>(FunctionId::SYSTEM_RESET),
+            static_cast<uint32_t>(reset_type),
+            static_cast<uint32_t>(reset_reason));
+    }
+
+}  // End namespace opensbi::srst
+}  // End namespace drivers
+
diff --git a/kernel/drivers/opensbi/include/opensbi/extensions/srst.h b/kernel/drivers/opensbi/include/opensbi/extensions/srst.h
new file mode 100644
index 0000000..4ca9473
--- /dev/null
+++ b/kernel/drivers/opensbi/include/opensbi/extensions/srst.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include "opensbi/opensbi.h"
+
+namespace drivers {
+namespace opensbi::srst {
+
+    enum class ResetType : uint32_t {
+        SHUTDOWN,
+        COLD_REBOOT,
+        WARM_REBOOT
+        // 0x00000003 - 0xEFFFFFFF: Reserved
+        // 0xF0000000 - 0xFFFFFFFF: Vendor specific
+    };
+
+    enum class ResetReason : uint32_t {
+        NO_REASON,
+        SYSTEM_FAILURE
+        // 0x00000002 - 0xDFFFFFFF: Reserved
+        // 0xE0000000 - 0xEFFFFFFF: SBI implimentation specific
+        // 0xF0000000 - 0xFFFFFFFF: Vendor or platform specific
+    };
+
+    SbiRet system_reset(
+            ResetType reset_type,
+            ResetReason reset_reason);
+
+}  // End namespace opensbi::srst
+}  // End namespace drivers
diff --git a/kernel/drivers/opensbi/meson.build b/kernel/drivers/opensbi/meson.build
index 9156f91..fcb45e3 100644
--- a/kernel/drivers/opensbi/meson.build
+++ b/kernel/drivers/opensbi/meson.build
@@ -6,7 +6,8 @@ kernel_sources += [
         'extensions/timer.cpp',
         'extensions/ipi.cpp',
         'extensions/rfence.cpp',
-        'extensions/hsm.cpp'
+        'extensions/hsm.cpp',
+        'extensions/srst.cpp'
     ),
 ]