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