20000317 sourceware import

libgloss/i960/crt0.c

@@ -0,0 +1,66 @@
+extern int main(int argc, char **argv, char **envp);
+extern int brk (void *value);
+
+extern char bss_start;
+extern char end;
+
+char *__env[1] = {0};
+char **environ = __env;
+
+#define ENABLE_TRACE_MASK 1
+
+__inline static void 
+enable_tracing (void)
+{
+    register int mask = ENABLE_TRACE_MASK;
+    __asm__ volatile ("modpc %0,%0,%0"
+	              :
+	              : "d" (mask));
+}
+
+#define STACK_ALIGN 64
+
+__inline static void
+set_stack (void* ptr)
+{
+    ptr = (void *)(((int)ptr + STACK_ALIGN - 1) & ~(STACK_ALIGN - 1));
+    /* SP must be 64 bytes larger than FP at start.  */
+    __asm__ volatile ("mov %0,sp"
+	              :
+	              : "d" (ptr+STACK_ALIGN));
+    __asm__ volatile ("mov %0,fp"
+	              :
+	              : "d" (ptr));
+}
+
+__inline static void 
+init_Cregs (void)
+{
+    /* set register values gcc like */
+    register unsigned int mask0=0x3b001000;
+    register unsigned int mask1=0x00009107;
+    __asm__ volatile ("mov   %0,g14"
+                      :                      /* no output */
+                      : "I" (0));            /* gnu structure pointer */
+    __asm__ volatile ("modac %1,%0,%0"
+                      :                      /* no output */
+                      : "d" (mask0),
+                        "d" (mask1));        /* fpu control kb */
+}
+
+void
+_start(void)
+{
+  char *p;
+
+  enable_tracing ();
+  set_stack (&end);
+  init_Cregs ();
+  /* The stack grows upwards, so this makes the heap start after a 256K
+     stack area.  PlumHall known to fail with less than 73K of stack.  */
+  brk (&end+0x40000);
+  /* clear bss */
+  memset (&bss_start, 0, &end - &bss_start);
+  main(0, 0, 0);
+  exit(0);
+}