Add bpc service with ShutdownSystem and RebootSystem commands (#144)

nx/include/switch/services/bpc.h

@@ -0,0 +1,14 @@
+/**
+ * @file bpc.h
+ * @brief Board power control (bpc) service IPC wrapper.
+ * @author XorTroll
+ * @copyright libnx Authors
+ */
+#pragma once
+#include "../types.h"
+
+Result bpcInitialize(void);
+void bpcExit(void);
+
+Result bpcShutdownSystem(void);
+Result bpcRebootSystem(void);

nx/source/services/bpc.c

@@ -0,0 +1,93 @@
+#include "types.h"
+#include "result.h"
+#include "arm/atomics.h"
+#include "kernel/ipc.h"
+#include "kernel/detect.h"
+#include "services/bpc.h"
+#include "services/sm.h"
+
+static Service g_bpcSrv;
+static u64 g_refCnt;
+
+Result bpcInitialize(void)
+{
+    Result rc = 0;
+    
+    atomicIncrement64(&g_refCnt);
+
+    if (serviceIsActive(&g_bpcSrv))
+        return 0;
+
+    rc = smGetService(&g_bpcSrv, kernelAbove200() ? "bpc" : "bpc:c");
+
+    return rc;
+}
+
+void bpcExit(void)
+{
+    if (atomicDecrement64(&g_refCnt) == 0)
+        serviceClose(&g_bpcSrv);
+}
+
+Result bpcShutdownSystem(void)
+{
+    IpcCommand c;
+    ipcInitialize(&c);
+    
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+    
+    raw = ipcPrepareHeader(&c, sizeof(*raw));
+    
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 0;
+    
+    Result rc = serviceIpcDispatch(&g_bpcSrv);
+    
+    if(R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        ipcParse(&r);
+        
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp = r.Raw;
+        
+        rc = resp->result;
+    }
+    
+    return rc;
+}
+
+Result bpcRebootSystem(void)
+{
+    IpcCommand c;
+    ipcInitialize(&c);
+    
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+    
+    raw = ipcPrepareHeader(&c, sizeof(*raw));
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 1;
+    
+    Result rc = serviceIpcDispatch(&g_bpcSrv);
+    
+    if(R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        ipcParse(&r);
+        
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp = r.Raw;
+        
+        rc = resp->result;
+    }
+    
+    return rc;
+}