solaris.xtra.patchfreq revision 290001 
1#!/bin/ksh
2
3#
4# File:         patchfreq
5# Author:       Bryan Cantrill (bmc@eng.sun.com), Solaris Performance
6# Modified:     Sat Apr 26 04:00:59 PDT 1997
7#
8# This is a little script to patch a 5.5 or 5.5.1 kernel to get around
9# the cpu_tick_freq inaccuracy.  Before running this script, one must
10# know the true frequency of one's CPU;  this can be derived by NTP,
11# or by observing the clock relative to the time-of-day chip over a
12# long period of time (the TOD will pull system time when it drifts
13# by more than two seconds).
14#
15# Patching a kernel can render a machine unbootable;  do not run this
16# script unless you are prepared to accept that possibility.  It
17# is advisable to have a backout path (e.g. net booting, an alternate
18# boot disk, an installation CD) should your machine fail to boot.
19#
20# This is not a product of Sun Microsystems, and is provided "as is",
21# without warranty of any kind expressed or implied including, but not
22# limited to, the suitability of this script for any purpose.
23#
24
25if [ $# -eq 0 ]; then
26        echo "Usage:  $0 cpu_tick_freq [ alternate_kernel ]"
27        exit 1
28fi
29
30cpu_tick_freq=$1
31kernel=/platform/sun4u/kernel/unix
32
33if [ $# -eq 2 ]; then
34        kernel=$2
35fi
36
37if [ ! -w $kernel ]; then
38        echo "$0:  Cannot open $kernel for writing."
39        exit 1
40fi
41
42arch=`echo utsname+404?s | adb $kernel | cut -d: -f2`
43
44if [ ! $arch = "sun4u" ]; then
45        echo "Patch only applies to sun4u"
46        exit 1
47fi
48
49rel=`echo utsname+202?s | adb $kernel | cut -d: -f2`
50
51if [ ! $rel = "5.5" ] && [ ! $rel = "5.5.1" ]; then
52        echo "Patch only applies to 5.5 or 5.5.1..."
53        exit 1
54fi
55
56nop="1000000"           # nop
57store_mask="ffffe000"   # mask out low 13 bits
58store="da256000"        # st      %o5, [%l5 + offset]
59
60instr=`echo setcpudelay+34?X | adb $kernel | cut -d: -f 2 | nawk '{ print $1 }'`
61
62if [ $instr = $nop ]; then
63        echo "Instruction already patched..."
64else
65        let masked="(16#$store_mask & 16#$instr) - 16#$store"
66        if [ $masked -ne 0 ]; then
67                echo "Couldn't find instruction to patch;  aborting."
68                exit 1
69        fi
70
71        if ! echo setcpudelay+34?W $nop | adb -w $kernel 1> /dev/null
72        then
73                echo "adb returned an unexpected error;  aborting."
74        fi
75fi
76
77echo "Patching cpu_tick_freq to $cpu_tick_freq..."
78
79if ! echo cpu_tick_freq?W 0t$cpu_tick_freq | adb -w $kernel 1> /dev/null; then
80        echo "adb returned an unexpected error;  aborting."
81        exit 1
82fi
83
84echo "$kernel successfully patched."
85exit 0
86