/* * JFFS2 -- Journalling Flash File System, Version 2. * * Copyright (C) 2001 Red Hat, Inc. * * Created by Arjan van de Ven <arjanv@redhat.com> * * Heavily modified by Russ Dill <Russ.Dill@asu.edu> in an attempt at * a little more speed. * * The original JFFS, from which the design for JFFS2 was derived, * was designed and implemented by Axis Communications AB. * * The contents of this file are subject to the Red Hat eCos Public * License Version 1.1 (the "Licence"); you may not use this file * except in compliance with the Licence.  You may obtain a copy of * the Licence at http://www.redhat.com/ * * Software distributed under the Licence is distributed on an "AS IS" * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. * See the Licence for the specific language governing rights and * limitations under the Licence. * * The Original Code is JFFS2 - Journalling Flash File System, version 2 * * Alternatively, the contents of this file may be used under the * terms of the GNU General Public License version 2 (the "GPL"), in * which case the provisions of the GPL are applicable instead of the * above.  If you wish to allow the use of your version of this file * only under the terms of the GPL and not to allow others to use your * version of this file under the RHEPL, indicate your decision by * deleting the provisions above and replace them with the notice and * other provisions required by the GPL.  If you do not delete the * provisions above, a recipient may use your version of this file * under either the RHEPL or the GPL. * */#include <config.h>#if (CONFIG_COMMANDS & CFG_CMD_JFFS2)#include <armboot.h>#include <types.h>#include <jffs2/jffs2.h>#include <jffs2/compr_rubin.h>void rubin_do_decompress(unsigned char *bits, unsigned char *in,			 unsigned char *page_out, __u32 destlen){	register char *curr = page_out;	char *end = page_out + destlen;	register unsigned long temp;	register unsigned long result;	register unsigned long p;	register unsigned long q;	register unsigned long rec_q;	register unsigned long bit;	register long i0;	unsigned long i;	/* init_pushpull */	temp = *(u32 *) in;	bit = 16;	/* init_rubin */	q = 0;	p = (long) (2 * UPPER_BIT_RUBIN);	/* init_decode */	rec_q = (in[0] << 8) | in[1];	while (curr < end) {		/* in byte */		result = 0;		for (i = 0; i < 8; i++) {			/* decode */			while ((q & UPPER_BIT_RUBIN) || ((p + q) <= UPPER_BIT_RUBIN)) {				q &= ~UPPER_BIT_RUBIN;				q <<= 1;				p <<= 1;				rec_q &= ~UPPER_BIT_RUBIN;				rec_q <<= 1;				rec_q |= (temp >> (bit++ ^ 7)) & 1;				if (bit > 31) {					bit = 0;					temp = *(++((u32 *) in));				}			}			i0 =  (bits[i] * p) >> 8;			if (i0 <= 0) i0 = 1;			/* if it fails, it fails, we have our crc			if (i0 >= p) i0 = p - 1; */			result >>= 1;			if (rec_q < q + i0) {				/* result |= 0x00; */				p = i0;			} else {				result |= 0x80;				p -= i0;				q += i0;			}		}		*(curr++) = result;	}}void dynrubin_decompress(unsigned char *data_in, unsigned char *cpage_out,		   unsigned long sourcelen, unsigned long dstlen){	unsigned char bits[8];	int c;	for (c=0; c<8; c++)		bits[c] = (256 - data_in[c]);	rubin_do_decompress(bits, data_in+8, cpage_out, dstlen);}#endif /* CFG_CMD_JFFS2 */