Delay each boot printk message by N milliseconds

configname: CONFIG_BOOT_PRINTK_DELAY

Linux Kernel Configuration
└─>Kernel hacking
└─>printk and dmesg options
└─>Delay each boot printk message by N milliseconds
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
This build option allows you to read kernel boot messages
by inserting a short delay after each one. The delay is
specified in milliseconds on the kernel command line,
using "boot_delay=N".

It is likely that you would also need to use "lpj=M" to preset
the "loops per jiffy" value.
See a previous boot log for the "lpj" value to use for your
system, and then set "lpj=M" before setting "boot_delay=N".
NOTE: Using this option may adversely affect SMP systems.
I.e., processors other than the first one may not boot up.
BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
what it believes to be lockup conditions.