use RBIT instruction of Thumb-2

ChangeLog

@@ -1,3 +1,12 @@
+2012-06-05  Niibe Yutaka  <gniibe@fsij.org>
+
+	Take advantage of the Thumb-2 "rbit" instruction.
+	* regnual/regnual.c (fetch): Reverse bits.
+	* src/usb_ctrl.c (rbit): New.  Deleted reverse32.
+	(download_check_crc32): Use rbit.
+	* tool/gnuk_upgrade.py (crc32): Just use binascii.crc32.
+	(crctab): Remove.
+
 2012-06-04  Niibe Yutaka  <gniibe@fsij.org>
 
 	Card holder certificate data object bug fixes.

regnual/regnual.c

@@ -147,14 +147,23 @@ static uint32_t result;
 static const uint8_t *const mem_info[] = { &_flash_start,  &_flash_end, };
 
 
-static uint32_t fetch (int i)
+static uint32_t rbit (uint32_t v)
 {
   uint32_t r;
 
-  r = (mem[i*4] << 24) | (mem[i*4+1] << 16) | (mem[i*4+2] << 8) | mem[i*4+3];
+  asm ("rbit	%0, %1" : "=r" (r) : "r" (v));
   return r;
 }
 
+static uint32_t fetch (int i)
+{
+  uint32_t v;
+
+  v = (mem[i*4+3] << 24) | (mem[i*4+2] << 16) | (mem[i*4+1] << 8) | mem[i*4];
+
+  return rbit (v);
+}
+
 struct CRC {
   __IO uint32_t DR;
   __IO uint8_t  IDR;
@@ -174,7 +183,7 @@ static uint32_t calc_crc32 (void)
   for (i = 0; i < 256/4; i++)
     CRC->DR = fetch (i);
 
-  return CRC->DR;
+  return rbit (CRC->DR);
 }
 
 

src/usb_ctrl.c

@@ -188,11 +188,11 @@ static const uint8_t *const mem_info[] = { &_regnual_start,  &__heap_end__, };
 #define USB_FSIJ_GNUK_DOWNLOAD 1
 #define USB_FSIJ_GNUK_EXEC     2
 
-static uint32_t reverse32 (uint32_t v)
+static uint32_t rbit (uint32_t v)
 {
   uint32_t r;
 
-  r = (v << 24) | ((v & 0xff00) << 8) | ((v & 0xff0000) >> 8) | (v >> 24);
+  asm ("rbit	%0, %1" : "=r" (r) : "r" (v));
   return r;
 }
 
@@ -206,9 +206,9 @@ static int download_check_crc32 (const uint32_t *end_p)
   CRC->CR = CRC_CR_RESET;
 
   for (p = (const uint32_t *)&_regnual_start; p < end_p; p++)
-    CRC->DR = reverse32 (*p);
+    CRC->DR = rbit (*p);
 
-  if ((CRC->DR ^ crc32) == 0xffffffff)
+  if ((rbit (CRC->DR) ^ crc32) == 0xffffffff)
     return USB_SUCCESS;
 
   return USB_UNSUPPORT;

tool/gnuk_upgrade.py

@@ -83,7 +83,7 @@ class regnual:
                                         value = 0, index = 0,
                                         buffer = data[j*256:j*256+256],
                                         timeout = 10000)
-            crc32code = crc32(data[j*256:j*256+256], 0xffffffff)
+            crc32code = crc32(data[j*256:j*256+256])
             res = self.__devhandle.controlMsg(requestType = 0xc0, request = 2,
                                               value = 0, index = 0, buffer = 4,
                                               timeout = 10000)
@@ -111,7 +111,7 @@ class regnual:
                                         value = 0, index = 0,
                                         buffer = data[j*256:],
                                         timeout = 10000)
-            crc32code = crc32(data[j*256:].ljust(256,chr(255)), 0xffffffff)
+            crc32code = crc32(data[j*256:].ljust(256,chr(255)))
             res = self.__devhandle.controlMsg(requestType = 0xc0, request = 2,
                                               value = 0, index = 0, buffer = 4,
                                               timeout = 10000)
@@ -411,77 +411,18 @@ def gpg_sign(keygrip, hash):
         raise ValueError, binascii.hexlify(signed)
     return signed
 
-crctab = [ 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc,
-           0x17c56b6b, 0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f,
-           0x2f8ad6d6, 0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a,
-           0x384fbdbd, 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
-           0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8,
-           0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
-           0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e,
-           0x95609039, 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
-           0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84,
-           0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027,
-           0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022,
-           0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
-           0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077,
-           0x30476dc0, 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c,
-           0x2e003dc5, 0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1,
-           0x1fcdbb16, 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
-           0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb,
-           0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
-           0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d,
-           0x40d816ba, 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
-           0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f,
-           0x8e6c3698, 0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044,
-           0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689,
-           0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
-           0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683,
-           0xd1799b34, 0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59,
-           0x608edb80, 0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c,
-           0x774bb0eb, 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
-           0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e,
-           0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
-           0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48,
-           0x0e56f0ff, 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
-           0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2,
-           0xe6ea3d65, 0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601,
-           0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604,
-           0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
-           0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6,
-           0x9ff77d71, 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad,
-           0x81b02d74, 0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7,
-           0x50c9b640, 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
-           0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd,
-           0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
-           0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b,
-           0x0fdc1bec, 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
-           0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679,
-           0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12,
-           0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af,
-           0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
-           0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5,
-           0x9e7d9662, 0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06,
-           0xa6322bdf, 0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03,
-           0xb1f740b4 ]
-
 def UNSIGNED(n):
     return n & 0xffffffff
 
-# (1) Alas, zlib.crc32 (== binascii.crc32) uses same polynomial, but in a
+def crc32(bytestr):
-#     different way of endian-ness.
+    crc = binascii.crc32(bytestr)
-# (2) POSIX cksum command uses same calculation, but the initial value
+    return UNSIGNED(crc)
-#     is different.
-def crc32(bytestr, crc):
-    for b in bytestr:
-        idx = (crc>>24)^ord(b)
-        crc = UNSIGNED((crc << 8)) ^ crctab[idx]
-    return UNSIGNED(~crc)
 
 def main(keygrip, data_regnual, data_upgrade):
     l = len(data_regnual)
     if (l & 0x03) != 0:
         data_regnual = data_regnual.ljust(l + 4 - (l & 0x03), chr(0))
-    crc32code = crc32(data_regnual, 0xffffffff)
+    crc32code = crc32(data_regnual)
     print "CRC32: %04x\n" % crc32code
     data_regnual += pack('<I', crc32code)
     for (dev, config, intf) in ccid_devices():