firmware/rolo.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2002 Randy D. Wood
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19
  20 #include "lcd.h"
  21 #include "kernel.h"
  22 #include "sprintf.h"
  23 #include "button.h"
  24 #include "file.h"
  25 #include "mpeg.h"
  26 #include "system.h"
  27 #include "i2c.h"
  28 #include "string.h"
  29
  30 #define IRQ0_EDGE_TRIGGER 0x80
  31
  32 static void rolo_error(char *text)
  33 {
  34     lcd_clear_display();
  35     lcd_puts(0, 0, "ROLO error:");
  36     lcd_puts_scroll(0, 1, text);
  37     lcd_update();
  38     button_get(true);
  39     lcd_stop_scroll();
  40 }
  41 /***************************************************************************
  42  *
  43  * Name: rolo_load_app(char *filename,int scrambled)
  44  * Filename must be a fully defined filename including the path and extension
  45  *
  46  ***************************************************************************/
  47 int rolo_load(char* filename) __attribute__ ((section (".topcode")));
  48 int rolo_load(char* filename)
  49 {
  50     int fd,slen;
  51     unsigned long length,file_length,i;
  52     extern unsigned char mp3buf[],mp3end;
  53     unsigned short checksum,file_checksum;
  54     unsigned char* ramstart = (void*)0x09000000;
  55     void (*start_func)(void) = (void*)ramstart + 0x200;
  56
  57     lcd_clear_display();
  58     lcd_puts(0, 0, "ROLO...");
  59     lcd_puts(0, 1, "Loading");
  60     lcd_update();
  61
  62     mpeg_stop();
  63
  64     fd = open(filename, O_RDONLY);
  65     if(-1 == fd) {
  66         rolo_error("File not found");
  67         return -1;
  68     }
  69
  70     /* Read file length from header and compare to real file length */
  71     length=lseek(fd,0,SEEK_END)-6;
  72     lseek(fd, 0, SEEK_SET);
  73     if(read(fd, &file_length, 4) != 4) {
  74         rolo_error("Error Reading File Length");
  75         return -1;
  76     }
  77     if (length != file_length) {
  78         rolo_error("File length mismatch");
  79         return -1;
  80     }
  81
  82     /* Read and save checksum */
  83     lseek(fd, 4, SEEK_SET);
  84     if (read(fd, &file_checksum, 2) != 2) {
  85         rolo_error("Error Reading checksum");
  86         return -1;
  87     }
  88     lseek(fd, 6, SEEK_SET);
  89
  90     /* verify that file can be read and descrambled */
  91     if ((&mp3buf[0] + (2*length)+4) >= &mp3end) {
  92         rolo_error("Not enough room to load file");
  93         return -1;
  94     }
  95
  96     if (read(fd, &mp3buf[length], length) != (int)length) {
  97         rolo_error("Error Reading File");
  98         return -1;
  99     }
 100
 101     lcd_puts(0, 1, "Descramble");
 102     lcd_update();
 103
 104     /* descramble */
 105     slen = length/4;
 106     for (i = 0; i < length; i++) {
 107         unsigned long addr = ((i % slen) << 2) + i/slen;
 108         unsigned char data = mp3buf[i+length];
 109         data = ~((data >> 1) | ((data << 7) & 0x80)); /* poor man's ROR */
 110         mp3buf[addr] = data;
 111     }
 112
 113     /* Compute checksum and verify against checksum from file header */
 114     checksum=0;
 115     for (i=0; i<length; i++)
 116         checksum += mp3buf[i];
 117
 118     if (checksum != file_checksum) {
 119         rolo_error("Checksum Error");
 120         return -1;
 121     }
 122
 123     lcd_puts(0, 1, "Executing     ");
 124     lcd_update();
 125
 126     /* Disable interrupts */
 127     asm("mov #15<<4,r6\n"
 128         "ldc r6,sr");
 129
 130     /* Calling these 2 initialization routines was necessary to get the
 131        the origional Archos version of the firmware to load and execute. */
 132     system_init();           /* Initialize system for restart */
 133     i2c_init();              /* Init i2c bus - it seems like a good idea */
 134     ICR = IRQ0_EDGE_TRIGGER; /* Make IRQ0 edge triggered */
 135
 136     /* move firmware to start of ram */
 137     for ( i=0; i < length/4+1; i++ )
 138         ((unsigned int*)ramstart)[i] = ((unsigned int*)mp3buf)[i];
 139
 140     start_func(); /* start new firmware */
 141
 142     return 0; /* this is never reached */
 143 }