#!/bin/ksh
#
# File: patchfreq
# Author: Bryan Cantrill (bmc@eng.sun.com), Solaris Performance
# Modified: Sat Apr 26 04:00:59 PDT 1997
#
# This is a little script to patch a 5.5 or 5.5.1 kernel to get around
# the cpu_tick_freq inaccuracy. Before running this script, one must
# know the true frequency of one's CPU; this can be derived by NTP,
# or by observing the clock relative to the time-of-day chip over a
# long period of time (the TOD will pull system time when it drifts
# by more than two seconds).
#
# Patching a kernel can render a machine unbootable; do not run this
# script unless you are prepared to accept that possibility. It
# is advisable to have a backout path (e.g. net booting, an alternate
# boot disk, an installation CD) should your machine fail to boot.
#
# This is not a product of Sun Microsystems, and is provided "as is",
# without warranty of any kind expressed or implied including, but not
# limited to, the suitability of this script for any purpose.
#
if [ $# -eq 0 ]; then
echo "Usage: $0 cpu_tick_freq [ alternate_kernel ]"
exit 1
fi
cpu_tick_freq=$1
kernel=/platform/sun4u/kernel/unix
if [ $# -eq 2 ]; then
kernel=$2
fi
if [ ! -w $kernel ]; then
echo "$0: Cannot open $kernel for writing."
exit 1
fi
arch=`echo utsname+404?s | adb $kernel | cut -d: -f2`
if [ ! $arch = "sun4u" ]; then
echo "Patch only applies to sun4u"
exit 1
fi
rel=`echo utsname+202?s | adb $kernel | cut -d: -f2`
if [ ! $rel = "5.5" ] && [ ! $rel = "5.5.1" ]; then
echo "Patch only applies to 5.5 or 5.5.1..."
exit 1
fi
nop="1000000" # nop
store_mask="ffffe000" # mask out low 13 bits
store="da256000" # st %o5, [%l5 + offset]
instr=`echo setcpudelay+34?X | adb $kernel | cut -d: -f 2 | nawk '{ print $1 }'`
if [ $instr = $nop ]; then
echo "Instruction already patched..."
else
let masked="(16#$store_mask & 16#$instr) - 16#$store"
if [ $masked -ne 0 ]; then
echo "Couldn't find instruction to patch; aborting."
exit 1
fi
if ! echo setcpudelay+34?W $nop | adb -w $kernel 1> /dev/null
then
echo "adb returned an unexpected error; aborting."
fi
fi
echo "Patching cpu_tick_freq to $cpu_tick_freq..."
if ! echo cpu_tick_freq?W 0t$cpu_tick_freq | adb -w $kernel 1> /dev/null; then
echo "adb returned an unexpected error; aborting."
exit 1
fi
echo "$kernel successfully patched."
exit 0
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