arch/xtensa/boot/lib/zmem.c

   1 #include <linux/zlib.h>
   2
   3 /* bits taken from ppc */
   4
   5 extern void *avail_ram, *end_avail;
   6
   7 void exit (void)
   8 {
   9   for (;;);
  10 }
  11
  12 void *zalloc(unsigned size)
  13 {
  14         void *p = avail_ram;
  15
  16         size = (size + 7) & -8;
  17         avail_ram += size;
  18         if (avail_ram > end_avail) {
  19                 //puts("oops... out of memory\n");
  20                 //pause();
  21                 exit ();
  22         }
  23         return p;
  24 }
  25
  26 #define HEAD_CRC        2
  27 #define EXTRA_FIELD     4
  28 #define ORIG_NAME       8
  29 #define COMMENT         0x10
  30 #define RESERVED        0xe0
  31
  32 #define DEFLATED        8
  33
  34 void gunzip (void *dst, int dstlen, unsigned char *src, int *lenp)
  35 {
  36         z_stream s;
  37         int r, i, flags;
  38
  39         /* skip header */
  40         i = 10;
  41         flags = src[3];
  42         if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
  43                 //puts("bad gzipped data\n");
  44                 exit();
  45         }
  46         if ((flags & EXTRA_FIELD) != 0)
  47                 i = 12 + src[10] + (src[11] << 8);
  48         if ((flags & ORIG_NAME) != 0)
  49                 while (src[i++] != 0)
  50                         ;
  51         if ((flags & COMMENT) != 0)
  52                 while (src[i++] != 0)
  53                         ;
  54         if ((flags & HEAD_CRC) != 0)
  55                 i += 2;
  56         if (i >= *lenp) {
  57                 //puts("gunzip: ran out of data in header\n");
  58                 exit();
  59         }
  60
  61         s.workspace = zalloc(zlib_inflate_workspacesize());
  62         r = zlib_inflateInit2(&s, -MAX_WBITS);
  63         if (r != Z_OK) {
  64                 //puts("inflateInit2 returned "); puthex(r); puts("\n");
  65                 exit();
  66         }
  67         s.next_in = src + i;
  68         s.avail_in = *lenp - i;
  69         s.next_out = dst;
  70         s.avail_out = dstlen;
  71         r = zlib_inflate(&s, Z_FINISH);
  72         if (r != Z_OK && r != Z_STREAM_END) {
  73                 //puts("inflate returned "); puthex(r); puts("\n");
  74                 exit();
  75         }
  76         *lenp = s.next_out - (unsigned char *) dst;
  77         zlib_inflateEnd(&s);
  78 }
  79