text: /*
   * (C) Copyright 2000-2006
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include <common.h>
  #include <watchdog.h>
  #include <command.h>
  #include <image.h>
  #include <malloc.h>
  #include <u-boot/zlib.h>
  
  #define	ZALLOC_ALIGNMENT	16
  #define HEAD_CRC		2
  #define EXTRA_FIELD		4
  #define ORIG_NAME		8
  #define COMMENT			0x10
  #define RESERVED		0xe0
  #define DEFLATED		8
  
  void *gzalloc(void *x, unsigned items, unsigned size)
  {
  	void *p;
  
  	size *= items;
  	size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1);
  
  	p = malloc (size);
  
  	return (p);
  }
  
  void gzfree(void *x, void *addr, unsigned nb)
  {
  	free (addr);
  }
  
  int gunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp)
  {
  	int i, flags;
  
  	/* skip header */
  	i = 10;
  	flags = src[3];
  	if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
  		puts ("Error: Bad gzipped data\n");
  		return (-1);
  	}
  	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 ("Error: gunzip out of data in header\n");
  		return (-1);
  	}
  
  	return zunzip(dst, dstlen, src, lenp, 1, i);
  }
  
  /*
   * Uncompress blocks compressed with zlib without headers
   */
  int zunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp,
  						int stoponerr, int offset)
  {
  	z_stream s;
  	int r;
  
  	s.zalloc = gzalloc;
  	s.zfree = gzfree;
  
  	r = inflateInit2(&s, -MAX_WBITS);
  	if (r != Z_OK) {
  		printf ("Error: inflateInit2() returned %d\n", r);
  		return -1;
  	}
  	s.next_in = src + offset;
  	s.avail_in = *lenp - offset;
  	s.next_out = dst;
  	s.avail_out = dstlen;
  	do {
  		r = inflate(&s, Z_FINISH);
  		if (stoponerr == 1 && r != Z_STREAM_END &&
  		    (s.avail_out == 0 || r != Z_BUF_ERROR)) {
  			printf("Error: inflate() returned %d\n", r);
  			inflateEnd(&s);
  			return -1;
  		}
  		s.avail_in = *lenp - offset - (int)(s.next_out - (unsigned char*)dst);
  	} while (r == Z_BUF_ERROR);
  	*lenp = s.next_out - (unsigned char *) dst;
  	inflateEnd(&s);
  
  	return 0;
  }
  