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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:29:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:29:51 +0000
commit6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e (patch)
tree32451fa3cdd9321fb2591fada9891b2cb70a9cd1 /grub-core/lib/crc.c
parentInitial commit. (diff)
downloadgrub2-6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e.tar.xz
grub2-6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e.zip
Adding upstream version 2.06.upstream/2.06upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'grub-core/lib/crc.c')
-rw-r--r--grub-core/lib/crc.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/grub-core/lib/crc.c b/grub-core/lib/crc.c
new file mode 100644
index 0000000..bf97cc6
--- /dev/null
+++ b/grub-core/lib/crc.c
@@ -0,0 +1,76 @@
+/* crc.c - crc function */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2008 Free Software Foundation, Inc.
+ *
+ * GRUB 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/types.h>
+#include <grub/lib/crc.h>
+
+static grub_uint32_t crc32c_table [256];
+
+/* Helper for init_crc32c_table. */
+static grub_uint32_t
+reflect (grub_uint32_t ref, int len)
+{
+ grub_uint32_t result = 0;
+ int i;
+
+ for (i = 1; i <= len; i++)
+ {
+ if (ref & 1)
+ result |= 1 << (len - i);
+ ref >>= 1;
+ }
+
+ return result;
+}
+
+static void
+init_crc32c_table (void)
+{
+ grub_uint32_t polynomial = 0x1edc6f41;
+ int i, j;
+
+ for(i = 0; i < 256; i++)
+ {
+ crc32c_table[i] = reflect(i, 8) << 24;
+ for (j = 0; j < 8; j++)
+ crc32c_table[i] = (crc32c_table[i] << 1) ^
+ (crc32c_table[i] & (1 << 31) ? polynomial : 0);
+ crc32c_table[i] = reflect(crc32c_table[i], 32);
+ }
+}
+
+grub_uint32_t
+grub_getcrc32c (grub_uint32_t crc, const void *buf, int size)
+{
+ int i;
+ const grub_uint8_t *data = buf;
+
+ if (! crc32c_table[1])
+ init_crc32c_table ();
+
+ crc^= 0xffffffff;
+
+ for (i = 0; i < size; i++)
+ {
+ crc = (crc >> 8) ^ crc32c_table[(crc & 0xFF) ^ *data];
+ data++;
+ }
+
+ return crc ^ 0xffffffff;
+}