mi4: replace chksum_crc32 with crc_32r

This uses an equivalent algorithm but with a different initial value
than we normally use (all bits off vs all bits on). Use the new crc_32r
to replace the original MI4 crc32 implementation.

This frees up some extra space on mi4 targets which gives us more
room on a few very space constrained targets (sansa c200/e200, etc).

Change-Id: Iaaac3ae353b30566156b1404cbf31ca32926203d

8 files changed, 6 insertions, 147 deletions

diff --git a/bootloader/fat32format.c b/bootloader/fat32format.c
index 540ee89b54..a885a5fced 100644
--- a/bootloader/fat32format.c
+++ b/bootloader/fat32format.c
@@ -44,7 +44,6 @@
 #include "storage.h"
 #include "button.h"
 #include "disk.h"
-#include "crc32-mi4.h"
 #include <string.h>
 #include "i2c.h"
 #include "backlight-target.h"
diff --git a/bootloader/main-e200r-installer.c b/bootloader/main-e200r-installer.c
index 5d1bff7b37..63b3fcb142 100644
--- a/bootloader/main-e200r-installer.c
+++ b/bootloader/main-e200r-installer.c
@@ -35,7 +35,7 @@
 #include "file.h"
 #include "button.h"
 #include "disk.h"
-#include "crc32-mi4.h"
+#include "crc32.h"
 #include <string.h>
 #include "i2c.h"
 #include "backlight-target.h"
@@ -138,7 +138,7 @@ void* main(void)
 
     storage_read_sectors(pinfo.start + START_SECTOR_OF_ROM + ROMSECTOR_TO_HACK,
                          1 , sector);
-    crc32 = chksum_crc32 (sector, 512);
+    crc32 = crc_32r (sector, 512, 0);
 
 #if 0 /* not needed in release builds */
     printf("--- Hack Status ---");
diff --git a/bootloader/main-pp.c b/bootloader/main-pp.c
index ef766455b6..08b5ea3ef5 100644
--- a/bootloader/main-pp.c
+++ b/bootloader/main-pp.c
@@ -37,7 +37,7 @@
 #include "adc.h"
 #include "button.h"
 #include "disk.h"
-#include "crc32-mi4.h"
+#include "crc32.h"
 #include "mi4-loader.h"
 #include "loader_strerror.h"
 #include <string.h>
@@ -169,7 +169,7 @@ int load_mi4_part(unsigned char* buf, struct partinfo* pinfo,
                         (mi4header.mi4size-MI4_HEADER_SIZE)/512, buf);
 
     /* Check CRC32 to see if we have a valid file */
-    sum = chksum_crc32 (buf,mi4header.mi4size-MI4_HEADER_SIZE);
+    sum = crc_32r (buf,mi4header.mi4size-MI4_HEADER_SIZE,0);
 
     printf("Calculated CRC32: %x", sum);
 
diff --git a/firmware/SOURCES b/firmware/SOURCES
index 0a6d4d30c3..dc1ed865dd 100644
--- a/firmware/SOURCES
+++ b/firmware/SOURCES
@@ -242,9 +242,6 @@ common/crc32.c
 #ifdef MODEL_NUMBER
 common/loader_strerror.c
 #endif
-#ifdef MI4_FORMAT
-common/crc32-mi4.c
-#endif
 #ifdef RKW_FORMAT
 common/crc32-rkw.c
 #endif
diff --git a/firmware/common/crc32-mi4.c b/firmware/common/crc32-mi4.c
deleted file mode 100644
index e1a5769018..0000000000
--- a/firmware/common/crc32-mi4.c
+++ /dev/null
@@ -1,110 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id: crc32.c 10464 2006-08-05 20:19:10Z miipekk $
- *
- * Copyright (C) 2007 Barry Wardell
- *
- * 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.
- *
- ****************************************************************************/
-
-/*
- * We can't use the CRC32 implementation in the firmware library as it uses a
- * different polynomial. The polynomial needed is 0xEDB88320L
- *
- * CRC32 implementation taken from:
- *
- * efone - Distributed internet phone system.
- *
- * (c) 1999,2000 Krzysztof Dabrowski
- * (c) 1999,2000 ElysiuM deeZine
- *
- * 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.
- *
- */
-
-/* based on implementation by Finn Yannick Jacobs */
-
-#include "crc32-mi4.h"
-
-/* crc_tab[] -- this crcTable is being build by chksum_crc32GenTab().
- *      so make sure, you call it before using the other
- *      functions!
- */
-static const unsigned int crc_tab[256] = {
-    0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
-    0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
-    0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
-    0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
-    0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
-    0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
-    0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
-    0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
-    0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
-    0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
-    0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
-    0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
-    0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
-    0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
-    0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
-    0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
-    0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
-    0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
-    0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
-    0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
-    0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
-    0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
-    0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
-    0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
-    0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
-    0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
-    0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
-    0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
-    0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
-    0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
-    0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
-    0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
-    0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
-    0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
-    0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
-    0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
-    0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
-    0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
-    0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
-    0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
-    0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
-    0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
-    0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
-};
-
-/* chksum_crc() -- to a given block, this one calculates the
- *              crc32-checksum until the length is
- *              reached. the crc32-checksum will be
- *              the result.
- */
-unsigned int chksum_crc32 (unsigned char *block, unsigned int length)
-{
-   register unsigned long crc;
-   unsigned long i;
-
-   crc = 0;
-   for (i = 0; i < length; i++)
-   {
-      crc = ((crc >> 8) & 0x00FFFFFF) ^ crc_tab[(crc ^ *block++) & 0xFF];
-   }
-   return (crc);
-}
diff --git a/firmware/include/crc32-mi4.h b/firmware/include/crc32-mi4.h
deleted file mode 100644
index 431757271a..0000000000
--- a/firmware/include/crc32-mi4.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id: crc32.h 10464 2006-08-05 20:19:10Z miipekk $
- *
- * Copyright (C) 2007 Barry Wardell
- *
- * 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.
- *
- ****************************************************************************/
-#ifndef _CRC32_MI4_H
-#define _CRC32_MI4_H
-
-unsigned int chksum_crc32 (unsigned char *block, unsigned int length);
-#endif
diff --git a/firmware/rolo.c b/firmware/rolo.c
index 3496545cac..5f936c95f4 100644
--- a/firmware/rolo.c
+++ b/firmware/rolo.c
@@ -40,7 +40,6 @@
 
 #include "loader_strerror.h"
 #if defined(MI4_FORMAT)
-#include "crc32-mi4.h"
 #include "mi4-loader.h"
 #if defined(HAVE_BOOTDATA) && !defined(SIMULATOR)
 #include "bootdata.h"
diff --git a/firmware/target/arm/pp/mi4-loader.c b/firmware/target/arm/pp/mi4-loader.c
index 31b0065888..0104496e9d 100644
--- a/firmware/target/arm/pp/mi4-loader.c
+++ b/firmware/target/arm/pp/mi4-loader.c
@@ -27,12 +27,11 @@
 #include "config.h"
 #include "mi4-loader.h"
 #include "loader_strerror.h"
-#include "crc32-mi4.h"
+#include "crc32.h"
 #include "file.h"
 #if defined(HAVE_BOOTDATA)
 #include "system.h"
 #include "bootdata.h"
-#include "crc32.h"
 
 /* Write bootdata into location in FIRMWARE marked by magic header
  * Assumes buffer is already loaded with the firmware image
@@ -293,7 +292,7 @@ static int load_mi4_filename(unsigned char* buf,
         return EREAD_IMAGE_FAILED;
 
     /* Check CRC32 to see if we have a valid file */
-    sum = chksum_crc32 (buf, mi4header.mi4size - MI4_HEADER_SIZE);
+    sum = crc_32r (buf, mi4header.mi4size - MI4_HEADER_SIZE, 0);
 
     if(sum != mi4header.crc32)
         return EBAD_CHKSUM;