i386/ucla/src/lab5/lib/libmain.c

   1 // Called from entry.S to get us going.
   2 // entry.S already took care of defining envs, pages, vpd, and vpt.
   3
   4 #include <inc/lib.h>
   5
   6 asmlinkage void umain(int argc, char **argv);
   7
   8 const volatile struct Env *thisenv;
   9 // Make "env" (which you used in the last lab) a synonym for "thisenv"
  10 // (which you will use in future labs).
  11 static const volatile struct Env *env __attribute__((alias("thisenv")));
  12 const char *binaryname = "<unknown>";
  13
  14 asmlinkage void
  15 libmain(int argc, char **argv)
  16 {
  17         extern uintptr_t sctors[], ectors[];
  18         uintptr_t *ctorva;
  19
  20         // set env to point at our env structure in envs[].
  21         thisenv = 0; /* Really? */
  22
  23         // save the name of the program so that panic() can use it
  24         if (argc > 0)
  25                 binaryname = argv[0];
  26
  27         // Call any global constructors (e.g., defined by C++).
  28         // This relies on linker script magic to define the 'sctors' and
  29         // 'ectors' symbols; see user/user.ld.
  30         for (ctorva = ectors; ctorva > sctors; )
  31                 ((void(*)()) *--ctorva)();
  32
  33         // call user main routine
  34         umain(argc, argv);
  35
  36         // exit gracefully
  37         exit();
  38 }
  39