arch/xtensa/boot/lib/zmem.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/zlib.h>
   3
   4 /* bits taken from ppc */
   5
   6 extern void *avail_ram, *end_avail;
   7
   8 void exit (void)
   9 {
  10   for (;;);
  11 }
  12
  13 void *zalloc(unsigned size)
  14 {
  15         void *p = avail_ram;
  16
  17         size = (size + 7) & -8;
  18         avail_ram += size;
  19         if (avail_ram > end_avail) {
  20                 //puts("oops... out of memory\n");
  21                 //pause();
  22                 exit ();
  23         }
  24         return p;
  25 }
  26
  27 #define HEAD_CRC        2
  28 #define EXTRA_FIELD     4
  29 #define ORIG_NAME       8
  30 #define COMMENT         0x10
  31 #define RESERVED        0xe0
  32
  33 #define DEFLATED        8
  34
  35 void gunzip (void *dst, int dstlen, unsigned char *src, int *lenp)
  36 {
  37         z_stream s;
  38         int r, i, flags;
  39
  40         /* skip header */
  41         i = 10;
  42         flags = src[3];
  43         if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
  44                 //puts("bad gzipped data\n");
  45                 exit();
  46         }
  47         if ((flags & EXTRA_FIELD) != 0)
  48                 i = 12 + src[10] + (src[11] << 8);
  49         if ((flags & ORIG_NAME) != 0)
  50                 while (src[i++] != 0)
  51                         ;
  52         if ((flags & COMMENT) != 0)
  53                 while (src[i++] != 0)
  54                         ;
  55         if ((flags & HEAD_CRC) != 0)
  56                 i += 2;
  57         if (i >= *lenp) {
  58                 //puts("gunzip: ran out of data in header\n");
  59                 exit();
  60         }
  61
  62         s.workspace = zalloc(zlib_inflate_workspacesize());
  63         r = zlib_inflateInit2(&s, -MAX_WBITS);
  64         if (r != Z_OK) {
  65                 //puts("inflateInit2 returned "); puthex(r); puts("\n");
  66                 exit();
  67         }
  68         s.next_in = src + i;
  69         s.avail_in = *lenp - i;
  70         s.next_out = dst;
  71         s.avail_out = dstlen;
  72         r = zlib_inflate(&s, Z_FINISH);
  73         if (r != Z_OK && r != Z_STREAM_END) {
  74                 //puts("inflate returned "); puthex(r); puts("\n");
  75                 exit();
  76         }
  77         *lenp = s.next_out - (unsigned char *) dst;
  78         zlib_inflateEnd(&s);
  79 }
  80