LXR linux/arch/xtensa/boot/lib/zmem.c

   1#include <linux/zlib.h>
   2
   3/* bits taken from ppc */
   4
   5extern void *avail_ram, *end_avail;
   6
   7void exit (void)
   8{
   9  for (;;);
  10}
  11
  12void *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
  34void 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
  80