rockbox/firmware/decompressor/decompressor.c
Jens Arnold 2c52dee83f Self-extractor for on-disk firmware image: UCL decompressor in SH1 assembler - less than half the size of the compiled C function, and ~45% faster.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@18904 a1c6a512-1295-4272-9138-f99709370657
2008-10-28 21:07:53 +00:00

73 lines
2.5 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;
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 **/
#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"
);
}