Move ring0 package.

This allows the package to serve as a general purpose ring0 support package, as
opposed to being bound to specific sentry platforms.

Updates #5039

PiperOrigin-RevId: 355220044

1 files changed, 60 insertions, 0 deletions

diff --git a/pkg/ring0/entry_arm64.go b/pkg/ring0/entry_arm64.go
new file mode 100644
index 000000000..62a93f3d6
--- /dev/null
+++ b/pkg/ring0/entry_arm64.go
@@ -0,0 +1,60 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build arm64
+
+package ring0
+
+// This is an assembly function.
+//
+// The sysenter function is invoked in two situations:
+//
+//  (1) The guest kernel has executed a system call.
+//  (2) The guest application has executed a system call.
+//
+// The interrupt flag is examined to determine whether the system call was
+// executed from kernel mode or not and the appropriate stub is called.
+
+func El1_sync_invalid()
+func El1_irq_invalid()
+func El1_fiq_invalid()
+func El1_error_invalid()
+
+func El1_sync()
+func El1_irq()
+func El1_fiq()
+func El1_error()
+
+func El0_sync()
+func El0_irq()
+func El0_fiq()
+func El0_error()
+
+func El0_sync_invalid()
+func El0_irq_invalid()
+func El0_fiq_invalid()
+func El0_error_invalid()
+
+func Vectors()
+
+// Start is the CPU entrypoint.
+//
+// The CPU state will be set to c.Registers().
+func Start()
+func kernelExitToEl1()
+
+func kernelExitToEl0()
+
+// Shutdown execution
+func Shutdown()