1 #include <linux/zlib.h>
2
3 /* bits taken from ppc */
4
5 extern void *avail_ram, *end_avail;
6
exit(void)7 void exit (void)
8 {
9 for (;;);
10 }
11
zalloc(unsigned size)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
gunzip(void * dst,int dstlen,unsigned char * src,int * lenp)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
80