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authorMatt Fleming <matt.fleming@intel.com>2013-06-28 20:53:30 +0100
committerMatt Fleming <matt.fleming@intel.com>2013-07-05 13:50:03 +0100
commit487f7581b4a4639d237a4a27a50252adabac62af (patch)
tree995e902be080517f3ebc745d27d36bb50a3314cb /com32/modules
parentbbd9262c2323c1df461f18fcfa2aed56cd2411ce (diff)
downloadsyslinux-487f7581b4a4639d237a4a27a50252adabac62af.tar.gz
syslinux-487f7581b4a4639d237a4a27a50252adabac62af.tar.xz
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debug.c32: Dynamically enable/disable debug code at runtime
It's useful to be able to enable (and disable) debug code at runtime, particularly for allowing users that are unable to build their own Syslinux releases the chance to provide useful debugging output. For example, say a user reports trouble with their PXE stack but doesn't have a development environment setup to turn on the debug code themselves. With this change you can simply request that they do, debug.c32 -e pxe_call unload_pxe open_file to enable the debug in those functions. By only turning on code in specific functions we reduce the chance of disrupting the buggy behaviour and improve the signal to noise ratio for print statements. To disable debug code use the -d flag, debug.c32 -d pxe_call To use this new feature simply do, if (syslinux_debug_enabled) { debug1(); debug2(); .... } from within the function you wish to add debug code. Note that this feature is not limited to print statements - you can put any code within the conditional, such as verifying a checksum or checking for memory leaks. The plan is to leave the dynamic debug code built in for all prereleases and to turn it off for final releases. People may still want to build with all dprintf() statements enabled, and so a new symbol, DYNAMIC_DEBUG, was introduced rather than repurposing the old DEBUG, DEBUG_STDIO and DEBUG_PORT symbols. Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Diffstat (limited to 'com32/modules')
-rw-r--r--com32/modules/Makefile2
-rw-r--r--com32/modules/debug.c54
2 files changed, 55 insertions, 1 deletions
diff --git a/com32/modules/Makefile b/com32/modules/Makefile
index 682e1b22..d801a260 100644
--- a/com32/modules/Makefile
+++ b/com32/modules/Makefile
@@ -25,7 +25,7 @@ MODULES = config.c32 ethersel.c32 dmitest.c32 cpuidtest.c32 \
kbdmap.c32 cmd.c32 vpdtest.c32 host.c32 ls.c32 gpxecmd.c32 \
ifcpu.c32 cpuid.c32 cat.c32 pwd.c32 ifplop.c32 zzjson.c32 \
whichsys.c32 prdhcp.c32 pxechn.c32 kontron_wdt.c32 ifmemdsk.c32 \
- hexdump.c32 poweroff.c32 cptime.c32
+ hexdump.c32 poweroff.c32 cptime.c32 debug.c32
TESTFILES =
diff --git a/com32/modules/debug.c b/com32/modules/debug.c
new file mode 100644
index 00000000..1026ebf3
--- /dev/null
+++ b/com32/modules/debug.c
@@ -0,0 +1,54 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 2013 Intel Corporation; author: Matt Fleming
+ *
+ * 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
+ * the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston MA 02110-1301, USA; either version 2 of the License, or
+ * (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <syslinux/debug.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static char *progname;
+
+static void usage(void)
+{
+ fprintf(stderr, "Usage: %s [-e|-d] <func1> [<func2>, ...]\n", progname);
+}
+
+int main(int argc, char *argv[])
+{
+ bool enable;
+ int i;
+
+ progname = argv[0];
+
+ if (argc < 3) {
+ usage();
+ return -1;
+ }
+
+ if (!strncmp(argv[1], "-e", 2))
+ enable = true;
+ else if (!strncmp(argv[1], "-d", 2))
+ enable = false;
+ else {
+ usage();
+ return -1;
+ }
+
+ for (i = 2; i < argc; i++) {
+ char *str = argv[i];
+
+ if (syslinux_debug(str, enable) < 0)
+ fprintf(stderr, "Failed to debug symbol \"%s\"\n", str);
+ }
+
+ return 0;
+}