crc-mi4: use const lookup table for crc

This doesn't touch external tools as I see no need for.

Change-Id: Ia69248c4b6a033c3772916525257e3540bddcffa
Reviewed-on: http://gerrit.rockbox.org/891
Tested: Sebastian Leonhardt <sebastian.leonhardt@web.de>
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>

6 files changed, 45 insertions, 41 deletions

diff --git a/bootloader/main-e200r-installer.c b/bootloader/main-e200r-installer.c
index 178a03b42e..dca34ec699 100644
--- a/bootloader/main-e200r-installer.c
+++ b/bootloader/main-e200r-installer.c
@@ -94,8 +94,6 @@ void* main(void)
     char sector[512];
     struct partinfo* pinfo;
 
-    chksum_crc32gentab ();
-
     system_init();
     kernel_init();
     lcd_init();
diff --git a/bootloader/main-pp.c b/bootloader/main-pp.c
index 7caf397f9f..cb629a76b2 100644
--- a/bootloader/main-pp.c
+++ b/bootloader/main-pp.c
@@ -298,8 +298,6 @@ void* main(void)
 #endif
     int usb = USB_EXTRACTED;
 
-    chksum_crc32gentab ();
-
     system_init();
     kernel_init();
 
diff --git a/bootloader/main-ppsansawipe.c b/bootloader/main-ppsansawipe.c
index 3221a09682..e54ad8d867 100644
--- a/bootloader/main-ppsansawipe.c
+++ b/bootloader/main-ppsansawipe.c
@@ -29,7 +29,6 @@
 #include "storage.h"
 #include "button.h"
 #include "disk.h"
-#include "crc32-mi4.h"
 #include <string.h>
 #include "i2c.h"
 #include "backlight-target.h"
@@ -176,8 +175,6 @@ void* main(void)
     int i;
     int btn;
 
-    chksum_crc32gentab ();
-
     system_init();
     kernel_init();
     lcd_init();
diff --git a/firmware/common/crc32-mi4.c b/firmware/common/crc32-mi4.c
index 82c6f3e15b..e1a5769018 100644
--- a/firmware/common/crc32-mi4.c
+++ b/firmware/common/crc32-mi4.c
@@ -45,7 +45,51 @@
  *      so make sure, you call it before using the other
  *      functions!
  */
-static unsigned int crc_tab[256];
+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
@@ -64,32 +108,3 @@ unsigned int chksum_crc32 (unsigned char *block, unsigned int length)
    }
    return (crc);
 }
-
-/* chksum_crc32gentab() --      to a global crc_tab[256], this one will
- *              calculate the crcTable for crc32-checksums.
- *              it is generated to the polynom [..]
- */
-
-void chksum_crc32gentab (void)
-{
-   unsigned long crc, poly;
-   int i, j;
-
-   poly = 0xEDB88320L;
-   for (i = 0; i < 256; i++)
-   {
-      crc = i;
-      for (j = 8; j > 0; j--)
-      {
-     if (crc & 1)
-     {
-        crc = (crc >> 1) ^ poly;
-     }
-     else
-     {
-        crc >>= 1;
-     }
-      }
-      crc_tab[i] = crc;
-   }
-}
diff --git a/firmware/include/crc32-mi4.h b/firmware/include/crc32-mi4.h
index e23398683d..431757271a 100644
--- a/firmware/include/crc32-mi4.h
+++ b/firmware/include/crc32-mi4.h
@@ -22,6 +22,4 @@
 #define _CRC32_MI4_H
 
 unsigned int chksum_crc32 (unsigned char *block, unsigned int length);
-void chksum_crc32gentab (void);
-
 #endif
diff --git a/firmware/target/arm/pp/mi4-loader.c b/firmware/target/arm/pp/mi4-loader.c
index c0031ea2f0..c465b898b4 100644
--- a/firmware/target/arm/pp/mi4-loader.c
+++ b/firmware/target/arm/pp/mi4-loader.c
@@ -207,8 +207,6 @@ int load_mi4(unsigned char* buf,
         return EREAD_IMAGE_FAILED;
 
     /* Check CRC32 to see if we have a valid file */
-    chksum_crc32gentab();
-
     sum = chksum_crc32 (buf, mi4header.mi4size - MI4_HEADER_SIZE);
 
     if(sum != mi4header.crc32)