Difference between revisions of "Problems with hwclock"
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=== Using the --directisa switch of hwclock(8) === | === Using the --directisa switch of hwclock(8) === | ||
| − | The '''hwclock''' command knows the parameter ''--directisa'' to access the system clock "directly" instead of accessing it by using /dev/rtc. There are several ways of doing this automatically. | + | The '''hwclock''' command knows the parameter ''--directisa'' to access the system clock "directly" instead of accessing it by using /dev/rtc. There are several ways of doing this automatically. |
| + | |||
| + | ==== Generic instructions ==== | ||
| + | Move /sbin/hwclock (or wherever it is located on your system) to '''/sbin/hwclock.dist''' and create the following shell script, which you place at /sbin/hwclock | ||
<pre>#!/bin/sh | <pre>#!/bin/sh | ||
| − | /sbin/hwclock.dist --directisa $ | + | /sbin/hwclock.dist --directisa "$@"</pre> |
Make the script executable (apply the same permissions you had for ''hwclock'' before) and keep your packaging system from overwriting it on updates. | Make the script executable (apply the same permissions you had for ''hwclock'' before) and keep your packaging system from overwriting it on updates. | ||
| − | + | ==== Debian 4.0 (etch) ==== | |
| + | Add the following to '''/etc/default/rcS''': | ||
| + | |||
| + | <pre>HWCLOCKPARS="--directisa"</pre> | ||
| + | |||
| + | ==== Debian 3.1 (sarge) and previous ==== | ||
| + | Edit '''/etc/init.d/hwclock.sh''' and change all instances of "/sbin/hwclock" to "/sbin/hwclock --directisa". | ||
=== Compiling RTC-support into the kernel instead of as a module === | === Compiling RTC-support into the kernel instead of as a module === | ||
Revision as of 04:39, 23 May 2007
This page discusses the problem with /dev/rtc on certain models.
Contents
Problem description
On bootup,a message like this shows up:
select() to /dev/rtc to wait for clock tick timed out
The RTC kernel driver can't handle the system clock.
Possible solutions
Using the --directisa switch of hwclock(8)
The hwclock command knows the parameter --directisa to access the system clock "directly" instead of accessing it by using /dev/rtc. There are several ways of doing this automatically.
Generic instructions
Move /sbin/hwclock (or wherever it is located on your system) to /sbin/hwclock.dist and create the following shell script, which you place at /sbin/hwclock
#!/bin/sh /sbin/hwclock.dist --directisa "$@"
Make the script executable (apply the same permissions you had for hwclock before) and keep your packaging system from overwriting it on updates.
Debian 4.0 (etch)
Add the following to /etc/default/rcS:
HWCLOCKPARS="--directisa"
Debian 3.1 (sarge) and previous
Edit /etc/init.d/hwclock.sh and change all instances of "/sbin/hwclock" to "/sbin/hwclock --directisa".
Compiling RTC-support into the kernel instead of as a module
Compiling RTC-support (CONFIG_RTC) into the kernel instead of compiling it as a module seems to work also. Tested on: 2.6.20.6 at Thinkpad Z61m 9450-3HG
Affected Models
Affected Operating Systems
- Linux, all flavours. Tested with kernel 2.6.18, 2.6.19, 2.6.20.6
