kgdboc: Add ekgdboc for early use of the kernel debugger

The ekgdboc= differs from kgdboc= in that you can begin debuggin as soon as the exceptions are setup and the kgdb I/O driver is available, instead of waiting until the tty subsystem is available. CC: kgdb-bugreport@lists.sourceforge.net Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

kgdboc: Add ekgdboc for early use of the kernel debugger
The ekgdboc= differs from kgdboc= in that you can begin debuggin as soon as the exceptions are setup and the kgdb I/O driver is available, instead of waiting until the tty subsystem is available. CC: kgdb-bugreport@lists.sourceforge.net Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Jason Wessel · Eric Lee
1 parent 0bb9fef913
Showing 2 changed files with 25 additions and 0 deletions Side-by-side Diff
Documentation/kernel-parameters.txt
drivers/serial/kgdboc.c
@@ -713,6 +713,12 @@
 			The VGA output is eventually overwritten by the real
 			console.
  
+	ekgdboc=	[X86,KGDB] Allow early kernel console debugging
+			ekgdboc=kbd
+
+			This is desgined to be used in conjunction with
+			the boot argument: earlyprintk=vga
+
 	eata=		[HW,SCSI]
  
 	edd=		[EDD]
@@ -223,6 +223,25 @@
 	.post_exception		= kgdboc_post_exp_handler,
 };
  
+#ifdef CONFIG_KGDB_SERIAL_CONSOLE
+/* This is only available if kgdboc is a built in for early debugging */
+int __init kgdboc_early_init(char *opt)
+{
+	/* save the first character of the config string because the
+	 * init routine can destroy it.
+	 */
+	char save_ch;
+
+	kgdboc_option_setup(opt);
+	save_ch = config[0];
+	init_kgdboc();
+	config[0] = save_ch;
+	return 0;
+}
+
+early_param("ekgdboc", kgdboc_early_init);
+#endif /* CONFIG_KGDB_SERIAL_CONSOLE */
+
 module_init(init_kgdboc);
 module_exit(cleanup_kgdboc);
 module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);
...	...	@@ -713,6 +713,12 @@
713	713	The VGA output is eventually overwritten by the real
714	714	console.
715	715
	716	+ ekgdboc= [X86,KGDB] Allow early kernel console debugging
	717	+ ekgdboc=kbd
	718	+
	719	+ This is desgined to be used in conjunction with
	720	+ the boot argument: earlyprintk=vga
	721	+
716	722	eata= [HW,SCSI]
717	723
718	724	edd= [EDD]
...	...	@@ -223,6 +223,25 @@
223	223	.post_exception = kgdboc_post_exp_handler,
224	224	};
225	225
	226	+#ifdef CONFIG_KGDB_SERIAL_CONSOLE
	227	+/* This is only available if kgdboc is a built in for early debugging */
	228	+int __init kgdboc_early_init(char *opt)
	229	+{
	230	+ /* save the first character of the config string because the
	231	+ * init routine can destroy it.
	232	+ */
	233	+ char save_ch;
	234	+
	235	+ kgdboc_option_setup(opt);
	236	+ save_ch = config[0];
	237	+ init_kgdboc();
	238	+ config[0] = save_ch;
	239	+ return 0;
	240	+}
	241	+
	242	+early_param("ekgdboc", kgdboc_early_init);
	243	+#endif /* CONFIG_KGDB_SERIAL_CONSOLE */
	244	+
226	245	module_init(init_kgdboc);
227	246	module_exit(cleanup_kgdboc);
228	247	module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);