This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
[RFA] gdbserver support for qCRC: (compare-sections)
- From: Michael Snyder <msnyder at vmware dot com>
- To: "gdb-patches at sourceware dot org" <gdb-patches at sourceware dot org>
- Date: Fri, 19 Mar 2010 16:27:35 -0700
- Subject: [RFA] gdbserver support for qCRC: (compare-sections)
This patch adds support to gdbserver for the "qCRC:" request.
This in turn supports the gdb "compare-sections" command, which
basically lets you verify that the binary image on the target
matches the executable that you're debugging.
I borrowed code from gdb/remote.c, I assume that's OK.
2010-03-19 Michael Snyder <msnyder@vmware.com>
* server.c (crc32): New function.
(handle_query): Add handling for 'qCRC:' request.
Index: server.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.c,v
retrieving revision 1.108
diff -u -p -r1.108 server.c
--- server.c 20 Jan 2010 22:55:38 -0000 1.108
+++ server.c 19 Mar 2010 23:23:15 -0000
@@ -788,6 +788,40 @@ handle_threads_qxfer (const char *annex,
}
+/* Table used by the crc32 function to calcuate the checksum. */
+
+static unsigned long crc32_table[256] =
+{0, 0};
+
+static unsigned long
+crc32 (CORE_ADDR base, int len, unsigned int crc)
+{
+ if (!crc32_table[1])
+ {
+ /* Initialize the CRC table and the decoding table. */
+ int i, j;
+ unsigned int c;
+
+ for (i = 0; i < 256; i++)
+ {
+ for (c = i << 24, j = 8; j > 0; --j)
+ c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1);
+ crc32_table[i] = c;
+ }
+ }
+
+ while (len--)
+ {
+ unsigned char byte = 0;
+
+ /* Fixme -- no error checking. */
+ read_inferior_memory (base, &byte, 1);
+ crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ byte) & 255];
+ base++;
+ }
+ return crc;
+}
+
/* Handle all of the extended 'q' packets. */
void
handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
@@ -1421,6 +1455,23 @@ handle_query (char *own_buf, int packet_
return;
}
+ if (strncmp ("qCRC:", own_buf, 5) == 0)
+ {
+ /* CRC check (compare-segment). */
+ char *comma;
+ CORE_ADDR base = strtoul (own_buf + 5, &comma, 16);
+ int len;
+
+ if (*comma++ != ',')
+ {
+ write_enn (own_buf);
+ return;
+ }
+ len = strtoul (comma, NULL, 16);
+ sprintf (own_buf, "C%lx", crc32 (base, len, 0xffffffff));
+ return;
+ }
+
/* Otherwise we didn't know what packet it was. Say we didn't
understand it. */
own_buf[0] = 0;