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authorJason Wessel <jason.wessel@windriver.com>2010-05-20 21:04:24 -0500
committerJason Wessel <jason.wessel@windriver.com>2010-05-20 21:04:24 -0500
commitada64e4c98eb5f04a9ca223c5ff9e7ac22ce6404 (patch)
tree48e284cf69157cf54302dcceb01ad7a07b889206 /drivers/serial
parenta0de055cf61338549b13079a5677ef2e1b6472ef (diff)
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kgdboc,keyboard: Keyboard driver for kdb with kgdb
This patch adds in the kdb PS/2 keyboard driver. This was mostly a direct port from the original kdb where I cleaned up the code against checkpatch.pl and added the glue to stitch it into kgdb. This patch also enables early kdb debug via kgdbwait and the keyboard. All the access to configure kdb using either a serial console or the keyboard is done via kgdboc. If you want to use only the keyboard and want to break in early you would add to your kernel command arguments: kgdboc=kbd kgdbwait If you wanted serial and or the keyboard access you could use: kgdboc=kbd,ttyS0 You can also configure kgdboc as a kernel module or at run time with the sysfs where you can activate and deactivate kgdb. Turn it on: echo kbd,ttyS0 > /sys/module/kgdboc/parameters/kgdboc Turn it off: echo "" > /sys/module/kgdboc/parameters/kgdboc Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/serial')
-rw-r--r--drivers/serial/kgdboc.c61
1 files changed, 54 insertions, 7 deletions
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c
index eadc1ab..ecef6e1 100644
--- a/drivers/serial/kgdboc.c
+++ b/drivers/serial/kgdboc.c
@@ -14,6 +14,7 @@
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/kgdb.h>
+#include <linux/kdb.h>
#include <linux/tty.h>
#define MAX_CONFIG_LEN 40
@@ -32,6 +33,40 @@ static struct kparam_string kps = {
static struct tty_driver *kgdb_tty_driver;
static int kgdb_tty_line;
+#ifdef CONFIG_KDB_KEYBOARD
+static int kgdboc_register_kbd(char **cptr)
+{
+ if (strncmp(*cptr, "kbd", 3) == 0) {
+ if (kdb_poll_idx < KDB_POLL_FUNC_MAX) {
+ kdb_poll_funcs[kdb_poll_idx] = kdb_get_kbd_char;
+ kdb_poll_idx++;
+ if (cptr[0][3] == ',')
+ *cptr += 4;
+ else
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static void kgdboc_unregister_kbd(void)
+{
+ int i;
+
+ for (i = 0; i < kdb_poll_idx; i++) {
+ if (kdb_poll_funcs[i] == kdb_get_kbd_char) {
+ kdb_poll_idx--;
+ kdb_poll_funcs[i] = kdb_poll_funcs[kdb_poll_idx];
+ kdb_poll_funcs[kdb_poll_idx] = NULL;
+ i--;
+ }
+ }
+}
+#else /* ! CONFIG_KDB_KEYBOARD */
+#define kgdboc_register_kbd(x) 0
+#define kgdboc_unregister_kbd()
+#endif /* ! CONFIG_KDB_KEYBOARD */
+
static int kgdboc_option_setup(char *opt)
{
if (strlen(opt) > MAX_CONFIG_LEN) {
@@ -45,25 +80,38 @@ static int kgdboc_option_setup(char *opt)
__setup("kgdboc=", kgdboc_option_setup);
+static void cleanup_kgdboc(void)
+{
+ kgdboc_unregister_kbd();
+ if (configured == 1)
+ kgdb_unregister_io_module(&kgdboc_io_ops);
+}
+
static int configure_kgdboc(void)
{
struct tty_driver *p;
int tty_line = 0;
int err;
+ char *cptr = config;
err = kgdboc_option_setup(config);
if (err || !strlen(config) || isspace(config[0]))
goto noconfig;
err = -ENODEV;
+ kgdb_tty_driver = NULL;
+
+ if (kgdboc_register_kbd(&cptr))
+ goto do_register;
- p = tty_find_polling_driver(config, &tty_line);
+ p = tty_find_polling_driver(cptr, &tty_line);
if (!p)
goto noconfig;
kgdb_tty_driver = p;
kgdb_tty_line = tty_line;
+do_register:
err = kgdb_register_io_module(&kgdboc_io_ops);
if (err)
goto noconfig;
@@ -75,6 +123,7 @@ static int configure_kgdboc(void)
noconfig:
config[0] = 0;
configured = 0;
+ cleanup_kgdboc();
return err;
}
@@ -88,20 +137,18 @@ static int __init init_kgdboc(void)
return configure_kgdboc();
}
-static void cleanup_kgdboc(void)
-{
- if (configured == 1)
- kgdb_unregister_io_module(&kgdboc_io_ops);
-}
-
static int kgdboc_get_char(void)
{
+ if (!kgdb_tty_driver)
+ return -1;
return kgdb_tty_driver->ops->poll_get_char(kgdb_tty_driver,
kgdb_tty_line);
}
static void kgdboc_put_char(u8 chr)
{
+ if (!kgdb_tty_driver)
+ return;
kgdb_tty_driver->ops->poll_put_char(kgdb_tty_driver,
kgdb_tty_line, chr);
}