1 files changed, 49 insertions, 0 deletions
diff --git a/newlib/libc/sys/cygwin/crt0.c b/newlib/libc/sys/cygwin/crt0.c
new file mode 100644
index 00000000000..d6bdd5a572c
--- /dev/null
+++ b/newlib/libc/sys/cygwin/crt0.c
@@ -0,0 +1,49 @@
+
+#ifdef __PPC__
+/* For the PowerPC, we want to make this function have its structured
+   exception table exception function point to something we control.  */
+
+extern void __cygwin_exception_handler();
+extern void mainCRTStartup(void) __attribute__((__exception__(__cygwin_exception_handler)));
+#endif
+
+/* In the following ifdef'd i386 code, the FPU precision is set to 80 bits
+   and all FPU exceptions are masked.  The former is needed to make long
+   doubles work correctly.  The latter causes the FPU to generate NaNs and
+   Infinities instead of signals for certain operations.
+*/
+
+#ifdef __i386__
+#define FPU_RESERVED 0xF0C0
+#define FPU_DEFAULT  0x033f
+
+/* For debugging on *#!$@ windbg.  bp for breakpoint.  */
+int __cygwin_crt0_bp = 0;
+#endif
+
+extern int main (int argc, char **argv);
+
+void
+mainCRTStartup ()
+{
+#ifdef __i386__
+  if (__cygwin_crt0_bp)
+    asm volatile ("int3");
+
+  {
+    volatile unsigned short cw;
+
+    /* Get Control Word */
+    __asm__ volatile ("fnstcw %0" : "=m" (cw) : );
+
+    /* mask in */
+    cw &= FPU_RESERVED;
+    cw |= FPU_DEFAULT;
+
+    /* set cw */
+    __asm__ volatile ("fldcw %0" :: "m" (cw));
+  }
+#endif
+
+  cygwin_crt0 (main);
+}