sys/src/9/port/rebootcmd.c

   1 #include        "u.h"
   2 #include        "../port/lib.h"
   3 #include        "mem.h"
   4 #include        "dat.h"
   5 #include        "fns.h"
   6 #include        "../port/error.h"
   7 #include        "a.out.h"
   8
   9 static void
  10 readn(Chan *c, void *vp, long n)
  11 {
  12         char *p = vp;
  13         long nn;
  14
  15         while(n > 0) {
  16                 nn = devtab[c->type]->read(c, p, n, c->offset);
  17                 if(nn == 0)
  18                         error(Eshort);
  19                 c->offset += nn;
  20                 p += nn;
  21                 n -= nn;
  22         }
  23 }
  24
  25 void
  26 rebootcmd(int argc, char *argv[])
  27 {
  28         struct {
  29                 Exec;
  30                 uvlong  hdr[1];
  31         } ehdr;
  32         Chan *c;
  33         ulong magic, text, rtext, entry, data, size, align;
  34         uchar *p;
  35
  36         if(argc == 0)
  37                 exit(0);
  38
  39         c = namec(argv[0], Aopen, OEXEC, 0);
  40         if(waserror()){
  41                 cclose(c);
  42                 nexterror();
  43         }
  44
  45         readn(c, &ehdr, sizeof(Exec));
  46         magic = beswal(ehdr.magic);
  47         entry = beswal(ehdr.entry);
  48         text = beswal(ehdr.text);
  49         data = beswal(ehdr.data);
  50
  51         if(!(magic == AOUT_MAGIC)){
  52                 switch(magic){
  53                 case I_MAGIC:
  54                 case S_MAGIC:
  55                         if((I_MAGIC == AOUT_MAGIC) || (S_MAGIC == AOUT_MAGIC))
  56                                 break;
  57                 default:
  58                         error(Ebadexec);
  59                 }
  60         }
  61         if(magic & HDR_MAGIC)
  62                 readn(c, ehdr.hdr, sizeof(ehdr.hdr));
  63
  64         switch(magic){
  65         case R_MAGIC:
  66                 align = 0x10000;        /* 64k segment alignment for arm64 */
  67                 break;
  68         default:
  69                 align = BY2PG;
  70                 break;
  71         }
  72
  73         /* round text out to page boundary */
  74         rtext = ROUND(entry+text, align)-entry;
  75         size = rtext + data;
  76         p = malloc(size);
  77         if(p == nil)
  78                 error(Enomem);
  79
  80         if(waserror()){
  81                 free(p);
  82                 nexterror();
  83         }
  84
  85         memset(p, 0, size);
  86         readn(c, p, text);
  87         readn(c, p + rtext, data);
  88
  89         ksetenv("bootfile", argv[0], 1);
  90
  91         reboot((void*)entry, p, size);
  92         error(Egreg);
  93 }