From 33da24d0e25f36a08bc2907d4a997f9bc666700f Mon Sep 17 00:00:00 2001
From: "C.W. Betts" <computers57@hotmail.com>
Date: Wed, 19 May 2021 15:42:50 -0600
Subject: [PATCH] macOS: Add support for Apple Silicon and usage of the MAP_JIT
 flag.

---
 src/386_dynarec.c       | 9 +++++++++
 src/codegen_allocator.c | 4 ++++
 src/pc.c                | 9 +++++++++
 3 files changed, 22 insertions(+)

diff --git a/src/386_dynarec.c b/src/386_dynarec.c
index 9dedf44..5b7e8f4 100644
--- a/src/386_dynarec.c
+++ b/src/386_dynarec.c
@@ -1,6 +1,9 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
+#if defined __APPLE__ && defined __aarch64__
+#include <pthread.h>
+#endif
 #include "ibm.h"
 #include "x86.h"
 #include "x86_ops.h"
@@ -410,6 +413,9 @@ static inline void exec_recompiler(void)
 
                 cpu_new_blocks++;
 
+#if defined __APPLE__ && defined __aarch64__
+                pthread_jit_write_protect_np(0);
+#endif
                 codegen_block_start_recompile(block);
                 codegen_in_recompile = 1;
 
@@ -481,6 +487,9 @@ static inline void exec_recompiler(void)
                         codegen_reset();
 
                 codegen_in_recompile = 0;
+#if defined __APPLE__ && defined __aarch64__
+                pthread_jit_write_protect_np(1);
+#endif
         }
         else if (!cpu_state.abrt)
         {
diff --git a/src/codegen_allocator.c b/src/codegen_allocator.c
index 5807b5d..a5301d1 100644
--- a/src/codegen_allocator.c
+++ b/src/codegen_allocator.c
@@ -30,6 +30,10 @@ void codegen_allocator_init()
 
 #if defined WIN32 || defined _WIN32 || defined _WIN32
         mem_block_alloc = VirtualAlloc(NULL, MEM_BLOCK_NR * MEM_BLOCK_SIZE, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
+        /* TODO: check deployment target: older Intel-based versions of macOS don't play
+           nice with MAP_JIT. */
+#elif defined(__APPLE__) && defined(MAP_JIT)
+        mem_block_alloc = mmap(0, MEM_BLOCK_NR * MEM_BLOCK_SIZE, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE|MAP_JIT, 0, 0);
 #else
         mem_block_alloc = mmap(0, MEM_BLOCK_NR * MEM_BLOCK_SIZE, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, 0, 0);
 #endif
diff --git a/src/pc.c b/src/pc.c
index 6ed0be9..f362378 100644
--- a/src/pc.c
+++ b/src/pc.c
@@ -1,6 +1,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#if defined(__APPLE__) && defined(__aarch64__)
+#include <pthread.h>
+#endif
 #include "ibm.h"
 #include "device.h"
 
@@ -307,7 +310,13 @@ void initpc(int argc, char *argv[])
         loadbios();
         mem_add_bios();
                         
+#if defined(__APPLE__) && defined(__aarch64__)
+        pthread_jit_write_protect_np(0);
+#endif
         codegen_init();
+#if defined(__APPLE__) && defined(__aarch64__)
+        pthread_jit_write_protect_np(1);
+#endif
         
         timer_reset();
         sound_reset();