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author | wdenk <wdenk> | 2002-11-03 00:38:21 +0000 |
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committer | wdenk <wdenk> | 2002-11-03 00:38:21 +0000 |
commit | fe8c2806cdba70479e351299881a395dc2be7785 (patch) | |
tree | a1e8b98a1838cba6e6f5c765d9d85339257c45f5 /fs/jffs2/compr_rubin.c | |
parent | f9087a3213cc245cf9b90436475b5af822bd7579 (diff) | |
download | u-boot-imx-fe8c2806cdba70479e351299881a395dc2be7785.zip u-boot-imx-fe8c2806cdba70479e351299881a395dc2be7785.tar.gz u-boot-imx-fe8c2806cdba70479e351299881a395dc2be7785.tar.bz2 |
Initial revision
Diffstat (limited to 'fs/jffs2/compr_rubin.c')
-rw-r--r-- | fs/jffs2/compr_rubin.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/fs/jffs2/compr_rubin.c b/fs/jffs2/compr_rubin.c new file mode 100644 index 0000000..cf01f88 --- /dev/null +++ b/fs/jffs2/compr_rubin.c @@ -0,0 +1,124 @@ +/* + * 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. + * + * $Id: compr_rubin.c,v 1.2 2002/01/24 22:58:42 rfeany Exp $ + * + */ + +#include <config.h> +#if (CONFIG_COMMANDS & CFG_CMD_JFFS2) + +#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 */ |