From 3b5e905ee3bd23e9311951890aba57a0dbc81ca4 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@au1.ibm.com>
Date: Wed, 7 Jun 2006 12:06:20 +1000
Subject: [PATCH] [PATCH] powerpc: Add udbg-immortal kernel option
When debugging early kernel crashes that happen after console_init() and
before a proper console driver takes over, we often have to go hack into
udbg.c to prevent it from unregistering so we can "see" what is
happening. This patch adds a kernel command line option "udbg-immortal"
instead to avoid having to modify the kernel.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/kernel/udbg.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c
index 3774e80094f53..67d9fd9ae2b53 100644
--- a/arch/powerpc/kernel/udbg.c
+++ b/arch/powerpc/kernel/udbg.c
@@ -14,6 +14,7 @@
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/console.h>
+#include <linux/init.h>
#include <asm/processor.h>
#include <asm/udbg.h>
@@ -141,12 +142,14 @@ static int early_console_initialized;
void __init disable_early_printk(void)
{
-#if 1
if (!early_console_initialized)
return;
+ if (strstr(saved_command_line, "udbg-immortal")) {
+ printk(KERN_INFO "early console immortal !\n");
+ return;
+ }
unregister_console(&udbg_console);
early_console_initialized = 0;
-#endif
}
/* called by setup_system */
--
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