From ec95016b0067d4801b743959345d1d2b4897b4c7 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 2 Sep 2011 14:41:29 +0200 Subject: [PATCH 058/290] printk: Add "force_early_printk" boot param to help with debugging Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.94-rt38.tar.xz Gives me an option to screw printk and actually see what the machine says. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1314967289.1301.11.camel@twins Signed-off-by: Thomas Gleixner Link: http://lkml.kernel.org/n/tip-ykb97nsfmobq44xketrxs977@git.kernel.org --- kernel/printk/printk.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 0214d876c22d..9a7f259dbb20 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -435,6 +435,13 @@ asmlinkage void early_printk(const char *fmt, ...) */ static bool __read_mostly printk_killswitch; +static int __init force_early_printk_setup(char *str) +{ + printk_killswitch = true; + return 0; +} +early_param("force_early_printk", force_early_printk_setup); + void printk_kill(void) { printk_killswitch = true; -- 2.24.1