[efi] Add "reboot" command for EFI

Abstract out the ability to reboot the system to a separate reboot()
function (with platform-specific implementations), add an EFI
implementation, and make the existing "reboot" command available under
EFI.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/efi/efi_reboot.h

@@ -0,0 +1,18 @@
+#ifndef _IPXE_EFI_REBOOT_H
+#define _IPXE_EFI_REBOOT_H
+
+/** @file
+ *
+ * iPXE reboot API for EFI
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#ifdef REBOOT_EFI
+#define REBOOT_PREFIX_efi
+#else
+#define REBOOT_PREFIX_efi __efi_
+#endif
+
+#endif /* _IPXE_EFI_REBOOT_H */

src/include/ipxe/null_reboot.h

@@ -0,0 +1,18 @@
+#ifndef _IPXE_NULL_REBOOT_H
+#define _IPXE_NULL_REBOOT_H
+
+/** @file
+ *
+ * iPXE do-nothing reboot API
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#ifdef REBOOT_NULL
+#define REBOOT_PREFIX_null
+#else
+#define REBOOT_PREFIX_null __null_
+#endif
+
+#endif /* _IPXE_NULL_REBOOT_H */

src/include/ipxe/reboot.h

@@ -0,0 +1,57 @@
+#ifndef _IPXE_REBOOT_H
+#define _IPXE_REBOOT_H
+
+/** @file
+ *
+ * iPXE reboot API
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <ipxe/api.h>
+#include <config/reboot.h>
+
+/**
+ * Calculate static inline reboot API function name
+ *
+ * @v _prefix		Subsystem prefix
+ * @v _api_func		API function
+ * @ret _subsys_func	Subsystem API function
+ */
+#define REBOOT_INLINE( _subsys, _api_func ) \
+	SINGLE_API_INLINE ( REBOOT_PREFIX_ ## _subsys, _api_func )
+
+/**
+ * Provide an reboot API implementation
+ *
+ * @v _prefix		Subsystem prefix
+ * @v _api_func		API function
+ * @v _func		Implementing function
+ */
+#define PROVIDE_REBOOT( _subsys, _api_func, _func ) \
+	PROVIDE_SINGLE_API ( REBOOT_PREFIX_ ## _subsys, _api_func, _func )
+
+/**
+ * Provide a static inline reboot API implementation
+ *
+ * @v _prefix		Subsystem prefix
+ * @v _api_func		API function
+ */
+#define PROVIDE_REBOOT_INLINE( _subsys, _api_func ) \
+	PROVIDE_SINGLE_API_INLINE ( REBOOT_PREFIX_ ## _subsys, _api_func )
+
+/* Include all architecture-independent reboot API headers */
+#include <ipxe/null_reboot.h>
+#include <ipxe/efi/efi_reboot.h>
+
+/* Include all architecture-dependent reboot API headers */
+#include <bits/reboot.h>
+
+/**
+ * Reboot system
+ *
+ */
+void reboot ( void );
+
+#endif /* _IPXE_REBOOT_H */