81 lines
2 KiB
C
81 lines
2 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/zlib.h>
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/* bits taken from ppc */
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extern void *avail_ram, *end_avail;
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void exit (void)
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{
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for (;;);
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}
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void *zalloc(unsigned size)
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{
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void *p = avail_ram;
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size = (size + 7) & -8;
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avail_ram += size;
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if (avail_ram > end_avail) {
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//puts("oops... out of memory\n");
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//pause();
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exit ();
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}
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return p;
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}
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#define HEAD_CRC 2
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#define EXTRA_FIELD 4
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#define ORIG_NAME 8
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#define COMMENT 0x10
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#define RESERVED 0xe0
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#define DEFLATED 8
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void gunzip (void *dst, int dstlen, unsigned char *src, int *lenp)
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{
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z_stream s;
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int r, i, flags;
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/* skip header */
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i = 10;
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flags = src[3];
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if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
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//puts("bad gzipped data\n");
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exit();
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}
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if ((flags & EXTRA_FIELD) != 0)
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i = 12 + src[10] + (src[11] << 8);
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if ((flags & ORIG_NAME) != 0)
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while (src[i++] != 0)
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;
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if ((flags & COMMENT) != 0)
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while (src[i++] != 0)
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;
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if ((flags & HEAD_CRC) != 0)
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i += 2;
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if (i >= *lenp) {
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//puts("gunzip: ran out of data in header\n");
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exit();
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}
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s.workspace = zalloc(zlib_inflate_workspacesize());
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r = zlib_inflateInit2(&s, -MAX_WBITS);
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if (r != Z_OK) {
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//puts("inflateInit2 returned "); puthex(r); puts("\n");
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exit();
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}
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s.next_in = src + i;
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s.avail_in = *lenp - i;
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s.next_out = dst;
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s.avail_out = dstlen;
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r = zlib_inflate(&s, Z_FINISH);
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if (r != Z_OK && r != Z_STREAM_END) {
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//puts("inflate returned "); puthex(r); puts("\n");
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exit();
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}
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*lenp = s.next_out - (unsigned char *) dst;
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zlib_inflateEnd(&s);
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}
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