start implementing the libretro interface. (not working yet)

1 files changed, 161 insertions, 0 deletions

diff --git a/libco/amd64.c b/libco/amd64.c
new file mode 100644
index 0000000..5d74bf6
--- /dev/null
+++ b/libco/amd64.c
@@ -0,0 +1,161 @@
+/*
+  libco.amd64 (2009-10-12)
+  author: byuu
+  license: public domain
+*/
+
+#define LIBCO_C
+#include <libco.h>
+#include <assert.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static thread_local long long co_active_buffer[64];
+static thread_local cothread_t co_active_handle = 0;
+static void (*co_swap)(cothread_t, cothread_t) = 0;
+
+#ifdef _WIN32
+//ABI: Win64
+static unsigned char co_swap_function[] = {
+  0x48, 0x89, 0x22,                                 /* mov    [rdx],rsp        */
+  0x48, 0x8b, 0x21,                                 /* mov    rsp,[rcx]        */
+  0x58,                                             /* pop    rax              */
+  0x48, 0x89, 0x6a, 0x08,                           /* mov    [rdx+0x8],rbp    */
+  0x48, 0x89, 0x72, 0x10,                           /* mov    [rdx+0x10],rsi   */
+  0x48, 0x89, 0x7a, 0x18,                           /* mov    [rdx+0x18],rdi   */
+  0x48, 0x89, 0x5a, 0x20,                           /* mov    [rdx+0x20],rbx   */
+  0x4c, 0x89, 0x62, 0x28,                           /* mov    [rdx+0x28],r12   */
+  0x4c, 0x89, 0x6a, 0x30,                           /* mov    [rdx+0x30],r13   */
+  0x4c, 0x89, 0x72, 0x38,                           /* mov    [rdx+0x38],r14   */
+  0x4c, 0x89, 0x7a, 0x40,                           /* mov    [rdx+0x40],r15   */
+  0x48, 0x81, 0xc2, 0x80, 0x00, 0x00, 0x00,         /* add    rdx,0x80         */
+  0x48, 0x83, 0xe2, 0xf0,                           /* and    rdx,-0x10        */
+  0x0f, 0x29, 0x32,                                 /* movaps [rdx],xmm6       */
+  0x0f, 0x29, 0x7a, 0x10,                           /* movaps [rdx+0x10],xmm7  */
+  0x44, 0x0f, 0x29, 0x42, 0x20,                     /* movaps [rdx+0x20],xmm8  */
+  0x44, 0x0f, 0x29, 0x4a, 0x30,                     /* movaps [rdx+0x30],xmm9  */
+  0x44, 0x0f, 0x29, 0x52, 0x40,                     /* movaps [rdx+0x40],xmm10 */
+  0x44, 0x0f, 0x29, 0x5a, 0x50,                     /* movaps [rdx+0x50],xmm11 */
+  0x44, 0x0f, 0x29, 0x62, 0x60,                     /* movaps [rdx+0x60],xmm12 */
+  0x44, 0x0f, 0x29, 0x6a, 0x70,                     /* movaps [rdx+0x70],xmm13 */
+  0x44, 0x0f, 0x29, 0xb2, 0x80, 0x00, 0x00, 0x00,   /* movaps [rdx+0x80],xmm14 */
+  0x44, 0x0f, 0x29, 0xba, 0x90, 0x00, 0x00, 0x00,   /* movaps [rdx+0x90],xmm15 */
+  0x48, 0x8b, 0x69, 0x08,                           /* mov    rbp,[rcx+0x8]    */
+  0x48, 0x8b, 0x71, 0x10,                           /* mov    rsi,[rcx+0x10]   */
+  0x48, 0x8b, 0x79, 0x18,                           /* mov    rdi,[rcx+0x18]   */
+  0x48, 0x8b, 0x59, 0x20,                           /* mov    rbx,[rcx+0x20]   */
+  0x4c, 0x8b, 0x61, 0x28,                           /* mov    r12,[rcx+0x28]   */
+  0x4c, 0x8b, 0x69, 0x30,                           /* mov    r13,[rcx+0x30]   */
+  0x4c, 0x8b, 0x71, 0x38,                           /* mov    r14,[rcx+0x38]   */
+  0x4c, 0x8b, 0x79, 0x40,                           /* mov    r15,[rcx+0x40]   */
+  0x48, 0x81, 0xc1, 0x80, 0x00, 0x00, 0x00,         /* add    rcx,0x80         */
+  0x48, 0x83, 0xe1, 0xf0,                           /* and    rcx,-0x10        */
+  0x0f, 0x29, 0x31,                                 /* movaps [rcx],xmm6       */
+  0x0f, 0x29, 0x79, 0x10,                           /* movaps [rcx+0x10],xmm7  */
+  0x44, 0x0f, 0x29, 0x41, 0x20,                     /* movaps [rcx+0x20],xmm8  */
+  0x44, 0x0f, 0x29, 0x49, 0x30,                     /* movaps [rcx+0x30],xmm9  */
+  0x44, 0x0f, 0x29, 0x51, 0x40,                     /* movaps [rcx+0x40],xmm10 */
+  0x44, 0x0f, 0x29, 0x59, 0x50,                     /* movaps [rcx+0x50],xmm11 */
+  0x44, 0x0f, 0x29, 0x61, 0x60,                     /* movaps [rcx+0x60],xmm12 */
+  0x44, 0x0f, 0x29, 0x69, 0x70,                     /* movaps [rcx+0x70],xmm13 */
+  0x44, 0x0f, 0x29, 0xb1, 0x80, 0x00, 0x00, 0x00,   /* movaps [rcx+0x80],xmm14 */
+  0x44, 0x0f, 0x29, 0xb9, 0x90, 0x00, 0x00, 0x00,   /* movaps [rcx+0x90],xmm15 */
+  0xff, 0xe0,                                       /* jmp    rax              */
+};
+
+#include <windows.h>
+
+void co_init(void)
+{
+   DWORD old_privileges;
+   VirtualProtect(co_swap_function,
+         sizeof(co_swap_function), PAGE_EXECUTE_READWRITE, &old_privileges);
+}
+#else
+//ABI: SystemV
+static unsigned char co_swap_function[] = {
+  0x48, 0x89, 0x26,                                 /* mov    [rsi],rsp      */
+  0x48, 0x8b, 0x27,                                 /* mov    rsp,[rdi]      */
+  0x58,                                             /* pop    rax            */
+  0x48, 0x89, 0x6e, 0x08,                           /* mov    [rsi+0x08],rbp */
+  0x48, 0x89, 0x5e, 0x10,                           /* mov    [rsi+0x10],rbx */
+  0x4c, 0x89, 0x66, 0x18,                           /* mov    [rsi+0x18],r12 */
+  0x4c, 0x89, 0x6e, 0x20,                           /* mov    [rsi+0x20],r13 */
+  0x4c, 0x89, 0x76, 0x28,                           /* mov    [rsi+0x28],r14 */
+  0x4c, 0x89, 0x7e, 0x30,                           /* mov    [rsi+0x30],r15 */
+  0x48, 0x8b, 0x6f, 0x08,                           /* mov    rbp,[rdi+0x08] */
+  0x48, 0x8b, 0x5f, 0x10,                           /* mov    rbx,[rdi+0x10] */
+  0x4c, 0x8b, 0x67, 0x18,                           /* mov    r12,[rdi+0x18] */
+  0x4c, 0x8b, 0x6f, 0x20,                           /* mov    r13,[rdi+0x20] */
+  0x4c, 0x8b, 0x77, 0x28,                           /* mov    r14,[rdi+0x28] */
+  0x4c, 0x8b, 0x7f, 0x30,                           /* mov    r15,[rdi+0x30] */
+  0xff, 0xe0,                                       /* jmp    rax            */
+};
+
+#include <unistd.h>
+#include <sys/mman.h>
+
+void co_init(void)
+{
+   unsigned long long addr = (unsigned long long)co_swap_function;
+   unsigned long long base = addr - (addr % sysconf(_SC_PAGESIZE));
+   unsigned long long size = (addr - base) + sizeof(co_swap_function);
+   mprotect((void*)base, size, PROT_READ | PROT_WRITE | PROT_EXEC);
+}
+#endif
+
+static void crash(void)
+{
+  assert(0); /* called only if cothread_t entrypoint returns */
+}
+
+cothread_t co_active(void)
+{
+  if (!co_active_handle)
+     co_active_handle = &co_active_buffer;
+  return co_active_handle;
+}
+
+cothread_t co_create(unsigned int size, void (*entrypoint)(void))
+{
+   cothread_t handle;
+
+   if(!co_swap)
+   {
+      co_init();
+      co_swap = (void (*)(cothread_t, cothread_t))co_swap_function;
+   }
+
+   if (!co_active_handle)
+      co_active_handle = &co_active_buffer;
+   size += 512; /* allocate additional space for storage */
+   size &= ~15; /* align stack to 16-byte boundary */
+
+   if(handle = (cothread_t)malloc(size))
+   {
+      long long *p = (long long*)((char*)handle + size); /* seek to top of stack */
+      *--p = (long long)crash;                           /* crash if entrypoint returns */
+      *--p = (long long)entrypoint;                      /* start of function */
+      *(long long*)handle = (long long)p;                /* stack pointer */
+   }
+
+   return handle;
+}
+
+void co_delete(cothread_t handle)
+{
+   free(handle);
+}
+
+void co_switch(cothread_t handle)
+{
+  register cothread_t co_previous_handle = co_active_handle;
+  co_swap(co_active_handle = handle, co_previous_handle);
+}
+
+#ifdef __cplusplus
+}
+#endif