rockbox/firmware/decompressor/decompressor.c
Jens Arnold 3a0e1cab69 Make a local function static.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@18639 a1c6a512-1295-4272-9138-f99709370657
2008-09-25 00:09:45 +00:00

138 lines
4.2 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 by Jens Arnold
*
* Self-extracting firmware loader to work around the 200KB size limit
* for archos player and recorder v1
* Decompresses a built-in UCL-compressed image (method 2e) and executes it.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "uclimage.h"
#define ICODE_ATTR __attribute__ ((section (".icode")))
/* Symbols defined in the linker script */
extern char iramcopy[], iramstart[], iramend[];
extern char stackend[];
extern char loadaddress[], dramend[];
/* Prototypes */
extern void start(void);
void main(void) ICODE_ATTR;
static int ucl_nrv2e_decompress_8(const unsigned char *src, unsigned char *dst,
unsigned long *dst_len) ICODE_ATTR;
/* Vector table */
void (*vbr[]) (void) __attribute__ ((section (".vectors"))) =
{
start, (void *)stackend,
start, (void *)stackend,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
};
/** All subsequent functions are executed from IRAM **/
/* Thinned out version of the UCL 2e decompression sourcecode
* Original (C) Markus F.X.J Oberhumer under GNU GPL license */
#define GETBIT(bb, src, ilen) \
(((bb = bb & 0x7f ? bb*2 : ((unsigned)src[ilen++]*2+1)) >> 8) & 1)
static int ucl_nrv2e_decompress_8(const unsigned char *src, unsigned char *dst,
unsigned long *dst_len)
{
unsigned long bb = 0;
unsigned ilen = 0, olen = 0, last_m_off = 1;
for (;;)
{
unsigned m_off, m_len;
while (GETBIT(bb,src,ilen))
dst[olen++] = src[ilen++];
m_off = 1;
for (;;)
{
m_off = m_off*2 + GETBIT(bb,src,ilen);
if (GETBIT(bb,src,ilen))
break;
m_off = (m_off-1)*2 + GETBIT(bb,src,ilen);
}
if (m_off == 2)
{
m_off = last_m_off;
m_len = GETBIT(bb,src,ilen);
}
else
{
m_off = (m_off-3)*256 + src[ilen++];
if (m_off == 0xffffffff)
break;
m_len = (m_off ^ 0xffffffff) & 1;
m_off >>= 1;
last_m_off = ++m_off;
}
if (m_len)
m_len = 1 + GETBIT(bb,src,ilen);
else if (GETBIT(bb,src,ilen))
m_len = 3 + GETBIT(bb,src,ilen);
else
{
m_len++;
do {
m_len = m_len*2 + GETBIT(bb,src,ilen);
} while (!GETBIT(bb,src,ilen));
m_len += 3;
}
m_len += (m_off > 0x500);
{
const unsigned char *m_pos;
m_pos = dst + olen - m_off;
dst[olen++] = *m_pos++;
do dst[olen++] = *m_pos++; while (--m_len > 0);
}
}
*dst_len = olen;
return ilen;
}
#define ALIGNED_IMG_SIZE ((sizeof(image) + 3) & ~3)
/* This will never return */
void main(void)
{
unsigned long dst_len; /* dummy */
unsigned long *src = (unsigned long *)image;
unsigned long *dst = (unsigned long *)(dramend - ALIGNED_IMG_SIZE);
do
*dst++ = *src++;
while (dst < (unsigned long *)dramend);
ucl_nrv2e_decompress_8(dramend - ALIGNED_IMG_SIZE, loadaddress, &dst_len);
asm(
"mov.l @%0+,r0 \n"
"jmp @r0 \n"
"mov.l @%0+,r15 \n"
: : "r"(loadaddress) : "r0"
);
}