LXR linux/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
   6extern void *avail_ram, *end_avail;
   7
   8void exit (void)
   9{
  10  for (;;);
  11}
  12
  13void *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
  35void 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
  81