1 files changed, 118 insertions, 0 deletions
diff --git a/coroutine/arm64/Context.h b/coroutine/arm64/Context.h
new file mode 100644
index 0000000000..468e4155b2
--- /dev/null
+++ b/coroutine/arm64/Context.h
@@ -0,0 +1,118 @@
+#ifndef COROUTINE_ARM64_CONTEXT_H
+#define COROUTINE_ARM64_CONTEXT_H 1
+
+/*
+ *  This file is part of the "Coroutine" project and released under the MIT License.
+ *
+ *  Created by Samuel Williams on 10/5/2018.
+ *  Copyright, 2018, by Samuel Williams.
+*/
+
+#pragma once
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#if defined __GNUC__
+#define COROUTINE __attribute__((noreturn)) void
+#define COROUTINE_DECL COROUTINE
+#elif defined _MSC_VER
+#define COROUTINE __declspec(noreturn) void
+#define COROUTINE_DECL void
+#endif
+
+#if defined(_WIN32)
+#define TEB_OFFSET 0x20
+#else
+#define TEB_OFFSET 0x00
+#endif
+
+enum {COROUTINE_REGISTERS = (0xa0 + TEB_OFFSET) / 8};
+
+#if defined(__SANITIZE_ADDRESS__)
+    #define COROUTINE_SANITIZE_ADDRESS
+#elif defined(__has_feature)
+    #if __has_feature(address_sanitizer)
+        #define COROUTINE_SANITIZE_ADDRESS
+    #endif
+#endif
+
+#if defined(COROUTINE_SANITIZE_ADDRESS)
+#include <sanitizer/common_interface_defs.h>
+#include <sanitizer/asan_interface.h>
+#endif
+
+struct coroutine_context
+{
+    void **stack_pointer;
+    void *argument;
+
+#if defined(COROUTINE_SANITIZE_ADDRESS)
+    void *fake_stack;
+    void *stack_base;
+    size_t stack_size;
+#endif
+};
+
+typedef COROUTINE_DECL(* coroutine_start)(struct coroutine_context *from, struct coroutine_context *self);
+
+static inline void coroutine_initialize_main(struct coroutine_context * context) {
+    context->stack_pointer = NULL;
+}
+
+static inline void *ptrauth_sign_instruction_addr(void *addr, void *modifier) {
+#if defined(__ARM_FEATURE_PAC_DEFAULT) && __ARM_FEATURE_PAC_DEFAULT != 0
+    // Sign the given instruction address with the given modifier and key A
+    register void *r17 __asm("r17") = addr;
+    register void *r16 __asm("r16") = modifier;
+    // Use HINT mnemonic instead of PACIA1716 for compatibility with older assemblers.
+    __asm ("hint #8;" : "+r"(r17) : "r"(r16));
+    addr = r17;
+#else
+    // No-op if PAC is not enabled
+#endif
+    return addr;
+}
+
+static inline void coroutine_initialize(
+    struct coroutine_context *context,
+    coroutine_start start,
+    void *stack,
+    size_t size
+) {
+    assert(start && stack && size >= 1024);
+
+#if defined(COROUTINE_SANITIZE_ADDRESS)
+    context->fake_stack = NULL;
+    context->stack_base = stack;
+    context->stack_size = size;
+#endif
+
+    // Stack grows down. Force 16-byte alignment.
+    char * top = (char*)stack + size;
+    top = (char *)((uintptr_t)top & ~0xF);
+    context->stack_pointer = (void**)top;
+
+    context->stack_pointer -= COROUTINE_REGISTERS;
+    memset(context->stack_pointer, 0, sizeof(void*) * COROUTINE_REGISTERS);
+
+    void *addr = (void*)(uintptr_t)start;
+    context->stack_pointer[(0x98 + TEB_OFFSET) / 8] = ptrauth_sign_instruction_addr(addr, (void*)top);
+#if defined(_WIN32)
+    // save top address of stack as base in TEB
+    context->stack_pointer[0x00 / 8] = (char*)stack + size;
+    // save botton address of stack as limit and deallocation stack in TEB
+    context->stack_pointer[0x08 / 8] = stack;
+    context->stack_pointer[0x10 / 8] = stack;
+#endif
+}
+
+struct coroutine_context * coroutine_transfer(struct coroutine_context * current, struct coroutine_context * target);
+
+static inline void coroutine_destroy(struct coroutine_context * context)
+{
+}
+
+#endif /* COROUTINE_ARM64_CONTEXT_H */