[Linux-ia64] [PATCH] EFI GPT CRC32 function fix - take 2

[Matt_Domsch@Dell.com]

My previous submission had an ugly comment inserted when the crc code was
put into OpenSSH, which said "All rights reserved".  Rather than trust that
no one would get upset over a one-line copyrighted function prototype,
here's a pass that should guarantee license compliance.  This applies
against the last 2.4.0-test10-ia64 patch.

Thanks,
Matt


diff -burN kernel24-2.4.0-test10/linux/fs/partitions/Makefile
kernel24-2.4.0-test10-crcfix/linux/fs/partitions/Makefile
--- kernel24-2.4.0-test10/linux/fs/partitions/Makefile	Thu Nov 30 15:47:31
2000
+++ kernel24-2.4.0-test10-crcfix/linux/fs/partitions/Makefile	Thu Nov 30
15:44:05 2000
@@ -8,7 +8,7 @@
 # Note 2! The CFLAGS definitions are now in the main makefile...
 
 O_TARGET := partitions.o
-OX_OBJS   := check.o
+OX_OBJS   := check.o efi_crc32.o
 
 obj-$(CONFIG_ACORN_PARTITION) += acorn.o
 obj-$(CONFIG_AMIGA_PARTITION) += amiga.o
diff -burN kernel24-2.4.0-test10/linux/fs/partitions/efi.c
kernel24-2.4.0-test10-crcfix/linux/fs/partitions/efi.c
--- kernel24-2.4.0-test10/linux/fs/partitions/efi.c	Thu Nov 30 15:47:31
2000
+++ kernel24-2.4.0-test10-crcfix/linux/fs/partitions/efi.c	Thu Nov 30
15:49:54 2000
@@ -4,8 +4,14 @@
  * http://developer.intel.com/technology/efi/efi.htm
  * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com> 
  *   Copyright 2000 Dell Computer Corporation
- * CRC routines taken from the EFI Sample Implementation,
- *   1999.12.31, lib/crc.c
+ *
+ * Note, the EFI Specification, v0.99, has a reference to
+ * Dr. Dobbs Journal, May 1994 (actually it's in May 1992)
+ * but that isn't the CRC function being used by EFI.  Intel's
+ * EFI Sample Implementation shows that they use the same function
+ * as was COPYRIGHT (C) 1986 Gary S. Brown.  See the files efi_crc32.[ch]
+ * for further information.
+ * 
  *
  *  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
@@ -25,6 +31,10 @@
  * TODO:
  *
  * Changelog:
+ * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * - Replaced Intel's CRC32 function with an equivalent
+ *   non-license-restricted version.
+ * 
  * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com>
  * - Fixed the LastLBA() call to return the proper last block
  * 
@@ -46,6 +56,7 @@
 #include <asm/efi.h>
 
 #include "check.h"
+#include "efi_crc32.h"
 #include "efi.h"
 
 #if CONFIG_BLK_DEV_MD && CONFIG_AUTODETECT_RAID
@@ -61,76 +72,7 @@
 #define debug_printk(...)
 #endif
 
-/* CRC routines taken from the EFI Sample Implementation,
- *   1999.12.31, lib/crc.c
- *
- * Note, the EFI Specification, v0.99, has a reference to
- * Dr. Dobbs Journal, May 1994 (actually it's in May 1992)
- * but that isn't the CRC function being used by EFI.
- */
-
-static u32 CRCTable[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 
-};
-
-static u32
-CalculateCrc (void *_pt, u32 Size)
-{
-	u8 *pt = (u8 *)_pt;
-	register u32 Crc;
 
-	/*  compute crc */
-	Crc = 0xffffffff;
-	while (Size) {
-		Crc = (Crc >> 8) ^ CRCTable[(__u8) Crc ^ *pt];
-		pt += 1;
-		Size -= 1;
-	}
-	Crc = Crc ^ 0xffffffff;
-	return Crc;
-}
 
 
 
@@ -387,7 +329,7 @@
 	/* Check the GUID Partition Table CRC */
 	origcrc = (*gpt)->HeaderCRC32;
 	(*gpt)->HeaderCRC32 = 0;
-	crc = CalculateCrc(*gpt, (*gpt)->HeaderSize);
+	crc = efi_crc32((const unsigned char *)(*gpt), (*gpt)->HeaderSize);
   
   
 	if (crc != origcrc) {
@@ -415,7 +357,8 @@
 	}
   
 	/* Check the GUID Partition Entry Array CRC */
-	crc = CalculateCrc(*ptes, (*gpt)->NumberOfPartitionEntries *
+	crc = efi_crc32((const unsigned char *)(*ptes),
+                    (*gpt)->NumberOfPartitionEntries *
 			   (*gpt)->SizeOfPartitionEntry);
   
 	if (crc != (*gpt)->PartitionEntryArrayCRC32)  {
diff -burN kernel24-2.4.0-test10/linux/fs/partitions/efi_crc32.c
kernel24-2.4.0-test10-crcfix/linux/fs/partitions/efi_crc32.c
--- kernel24-2.4.0-test10/linux/fs/partitions/efi_crc32.c	Wed Dec 31
18:00:00 1969
+++ kernel24-2.4.0-test10-crcfix/linux/fs/partitions/efi_crc32.c	Thu
Nov 30 15:43:38 2000
@@ -0,0 +1,127 @@
+/* 
+ * Nov 30, 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * - Copied crc32.c from the linux/drivers/net/cipe directory,
+ *   now named efi_crc32.[ch]
+ * - Modified it by seeding the crc with ~0 instead of 0, and
+ *   xor'ing the final value with ~0, per Intel EFI algorithm.
+ * - changed unsigned long to u32, added #include<linux/types.h>
+ * - changed len to be an unsigned long
+ * - changed crc32val to be a register
+ * - named the function efi_crc32() to be clear that it's different
+ * - License remains unchanged!  It's still GPL-compatable!
+ */
+
+  /* =============================== */
+  /*  COPYRIGHT (C) 1986 Gary S. Brown.  You may use this program, or
*/
+  /*  code or tables extracted from it, as desired without restriction.
*/
+  /*
*/
+  /*  First, the polynomial itself and its table of feedback terms.  The
*/
+  /*  polynomial is
*/
+  /*  X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0
*/
+  /*
*/
+  /*  Note that we take it "backwards" and put the highest-order term in
*/
+  /*  the lowest-order bit.  The X^32 term is "implied"; the LSB is the
*/
+  /*  X^31 term, etc.  The X^0 term (usually shown as "+1") results in
*/
+  /*  the MSB being 1.
*/
+  /*
*/
+  /*  Note that the usual hardware shift register implementation, which
*/
+  /*  is what we're using (we're merely optimizing it by doing eight-bit
*/
+  /*  chunks at a time) shifts bits into the lowest-order term.  In our
*/
+  /*  implementation, that means shifting towards the right.  Why do we
*/
+  /*  do it this way?  Because the calculated CRC must be transmitted in
*/
+  /*  order from highest-order term to lowest-order term.  UARTs transmit
*/
+  /*  characters in order from LSB to MSB.  By storing the CRC this way,
*/
+  /*  we hand it to the UART in the order low-byte to high-byte; the UART
*/
+  /*  sends each low-bit to hight-bit; and the result is transmission bit
*/
+  /*  by bit from highest- to lowest-order term without requiring any bit
*/
+  /*  shuffling on our part.  Reception works similarly.
*/
+  /*
*/
+  /*  The feedback terms table consists of 256, 32-bit entries.  Notes:
*/
+  /*
*/
+  /*      The table can be generated at runtime if desired; code to do so
*/
+  /*      is shown later.  It might not be obvious, but the feedback
*/
+  /*      terms simply represent the results of eight shift/xor opera-
*/
+  /*      tions for all combinations of data and CRC register values.
*/
+  /*
*/
+  /*      The values must be right-shifted by eight bits by the "updcrc"
*/
+  /*      logic; the shift must be unsigned (bring in zeroes).  On some
*/
+  /*      hardware you could probably optimize the shift in assembler by
*/
+  /*      using byte-swap instructions.
*/
+  /*      polynomial $edb88320
*/
+  /*
*/
+  /*  --------------------------------------------------------------------
*/
+
+#include "efi_crc32.h"
+
+static u32 efi_crc32_tab[] = {
+      0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+      0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+      0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+      0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+      0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+      0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+      0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+      0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+      0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+      0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+      0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+      0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+      0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+      0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+      0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+      0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+      0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+      0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+      0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+      0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+      0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+      0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+      0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+      0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+      0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+      0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+      0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+      0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+      0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+      0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+      0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+      0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+      0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+      0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+      0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+      0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+      0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+      0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+      0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+      0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+      0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+      0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+      0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+      0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+      0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+      0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+      0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+      0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+      0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+      0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+      0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+      0x2d02ef8dL
+   };
+
+/* Return a 32-bit CRC of the contents of the buffer. */
+
+u32 efi_crc32(const unsigned char *s, unsigned long len)
+{
+  unsigned long i;
+  register u32 crc32val;
+  
+  crc32val = ~0;
+  for (i = 0;  i < len;  i ++)
+    {
+      crc32val +	efi_crc32_tab[(crc32val ^ s[i]) & 0xff] ^
+	  (crc32val >> 8);
+    }
+  crc32val ^= ~0;
+  return crc32val;
+}
diff -burN kernel24-2.4.0-test10/linux/fs/partitions/efi_crc32.h
kernel24-2.4.0-test10-crcfix/linux/fs/partitions/efi_crc32.h
--- kernel24-2.4.0-test10/linux/fs/partitions/efi_crc32.h	Wed Dec 31
18:00:00 1969
+++ kernel24-2.4.0-test10-crcfix/linux/fs/partitions/efi_crc32.h	Thu
Nov 30 15:42:16 2000
@@ -0,0 +1,17 @@
+/*
+ * efi_crc32.h
+ * See efi_crc32.c for license and changes
+ */
+#ifndef EFI_CRC32_H
+#define EFI_CRC32_H
+
+#include <linux/types.h>
+
+/*
+ * This computes a 32 bit CRC of the data in the buffer, and returns the
CRC.
+ * The polynomial used is 0xedb88320.
+ */
+
+u32 efi_crc32(const unsigned char *buf, unsigned long len);
+
+#endif				/* EFI_CRC32_H */