/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