BUG/PATCH: Unable to specify console=ttyX where X != 0

BUG/PATCH: Unable to specify console=ttyX where X != 0

[Benjamin Reed]

[-- Attachment #1: Type: text/plain, Size: 607 bytes --]

The serial_console.txt file implies that you can specify other vt's
beside tty0 to use as a console using the console= kernel parameter. 
However, if you specify any ttyX it always goes to tty0.  Closer
examination shows that when the console is registered it is ignoring the
specified tty.

Basically, I want all the kernel messages to go to tty2 so that I can
have a nice clean user interaction on tty1, but still allow access to
kernel messages on tty2.

The following patch sets up the correct tty to send the messages to
based on the console= parameter and initializes the virtual terminal.

enjoy

ben

[-- Attachment #2: patch --]
[-- Type: text/plain, Size: 1844 bytes --]

--- console.c.old	Sun Aug 12 10:02:17 2001
+++ console.c	Wed Aug 22 16:17:11 2001
@@ -2369,6 +2369,21 @@
 
 DECLARE_TASKLET_DISABLED(console_tasklet, console_softint, 0);
 
+void __init con_setup_vt(unsigned int currcons)
+{
+        if (vc_cons[currcons].d) return;
+
+        vc_cons[currcons].d = (struct vc_data *)
+                              alloc_bootmem(sizeof(struct vc_data));
+        vt_cons[currcons] = (struct vt_struct *)
+                            alloc_bootmem(sizeof(struct vt_struct));
+        visual_init(currcons, 1);
+        screenbuf = (unsigned short *) alloc_bootmem(screenbuf_size);
+        kmalloced = 0;
+        vc_init(currcons, video_num_lines, video_num_columns,
+                currcons || !sw->con_save_screen);
+}
+
 void __init con_init(void)
 {
 	const char *display_desc = NULL;
@@ -2427,15 +2442,7 @@
 	 * kmalloc is not running yet - we use the bootmem allocator.
 	 */
 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
-		vc_cons[currcons].d = (struct vc_data *)
-				alloc_bootmem(sizeof(struct vc_data));
-		vt_cons[currcons] = (struct vt_struct *)
-				alloc_bootmem(sizeof(struct vt_struct));
-		visual_init(currcons, 1);
-		screenbuf = (unsigned short *) alloc_bootmem(screenbuf_size);
-		kmalloced = 0;
-		vc_init(currcons, video_num_lines, video_num_columns, 
-			currcons || !sw->con_save_screen);
+                con_setup_vt(currcons);
 	}
 	currcons = fg_console = 0;
 	master_display_fg = vc_cons[currcons].d;
@@ -2452,6 +2459,11 @@
 
 #ifdef CONFIG_VT_CONSOLE
 	register_console(&vt_console_driver);
+        if (vt_console_driver.index > 0 &&
+	    vt_console_driver.index < MAX_NR_CONSOLES) {
+                con_setup_vt(vt_console_driver.index-1);
+                kmsg_redirect = vt_console_driver.index;
+        }
 #endif
 
 	tasklet_enable(&console_tasklet);

Re: BUG/PATCH: Unable to specify console=ttyX where X != 0

[Paul]

Benjamin Reed <breed@almaden.ibm.com>, on Wed Aug 22, 2001 [04:35:03 PM] said:
> The serial_console.txt file implies that you can specify other vt's
> beside tty0 to use as a console using the console= kernel parameter. 
> However, if you specify any ttyX it always goes to tty0.  Closer
> examination shows that when the console is registered it is ignoring the
> specified tty.
> 
> Basically, I want all the kernel messages to go to tty2 so that I can
> have a nice clean user interaction on tty1, but still allow access to
> kernel messages on tty2.
> 
> The following patch sets up the correct tty to send the messages to
> based on the console= parameter and initializes the virtual terminal.
> 
> enjoy
> 
> ben

	Hello.

	Ben seems to be correct. Without this patch, the console=
boot param doesnt work as expected.
	eg. I use 'console=tty1 console=ttyS1,9600n8'
	Without the patch, printks go to the current vt
(tty0) instead of where they should. [they do go to the serial
console, propperly however] This is annoying, as I run
some X sessions on vt9/10 and wanted the logs to go to vt1 even
when I am in X. In fact, the default behaviour of having tty0 be
the console seems broken; if you _are_ using just vt's, you can't
leave the logging behind. (eg. this is a pain when verbose or
spurious logging is going on and you want to switch back and
forth between the logging vt and a working vt)
	I cannot vouch that this is the correct fix, but I
would like to see this fixed, or learn why it should not be.
	Here is Ben's patch vs. 2.4.9-ac10. It seems to work good
for me so far.

Paul
set@pobox.com

--- 2.4.9-ac10/drivers/char/console.c	Sun Sep  9 16:55:06 2001
+++ 2.4.9-ac10-cons/drivers/char/console.c	Sun Sep  9 22:57:22 2001
@@ -2425,6 +2425,21 @@
 struct tty_driver console_driver;
 static int console_refcount;
 
+void __init con_setup_vt(unsigned int currcons)
+{
+	if (vc_cons[currcons].d) return;
+
+	vc_cons[currcons].d = (struct vc_data *)
+		alloc_bootmem(sizeof(struct vc_data));
+	vt_cons[currcons] = (struct vt_struct *)
+		alloc_bootmem(sizeof(struct vt_struct));
+	visual_init(currcons, 1);
+	screenbuf = (unsigned short *) alloc_bootmem(screenbuf_size);
+	kmalloced = 0;
+	vc_init(currcons, video_num_lines, video_num_columns,
+		currcons || !sw->con_save_screen);
+}
+
 void __init con_init(void)
 {
 	const char *display_desc = NULL;
@@ -2483,15 +2498,7 @@
 	 * kmalloc is not running yet - we use the bootmem allocator.
 	 */
 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
-		vc_cons[currcons].d = (struct vc_data *)
-				alloc_bootmem(sizeof(struct vc_data));
-		vt_cons[currcons] = (struct vt_struct *)
-				alloc_bootmem(sizeof(struct vt_struct));
-		visual_init(currcons, 1);
-		screenbuf = (unsigned short *) alloc_bootmem(screenbuf_size);
-		kmalloced = 0;
-		vc_init(currcons, video_num_lines, video_num_columns, 
-			currcons || !sw->con_save_screen);
+		con_setup_vt(currcons);
 	}
 	currcons = fg_console = 0;
 	master_display_fg = vc_cons[currcons].d;
@@ -2508,6 +2515,12 @@
 
 #ifdef CONFIG_VT_CONSOLE
 	register_console(&vt_console_driver);
+        if (vt_console_driver.index > 0 &&
+	    vt_console_driver.index < MAX_NR_CONSOLES) {
+		con_setup_vt(vt_console_driver.index-1);
+		kmsg_redirect = vt_console_driver.index;
+	}
+
 #endif
 }