Messages in this thread | | | Date | Wed, 9 Jan 2002 14:45:03 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Re: system time issue |
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On 9 Jan 2002, Sipos Ferenc wrote:
> Hi! > > I have a redhat 7.2 box, and compiled the latest 2.4.18pre2 kernel with > the 2.4.18pre2aa1 patches in order to use gcc pre 3.1. When I shutdown > my system with the new kernel, it writes out normally: syncing system > time with hardware time, and with gcc 2.96 compiled kernels, everything > is ok, but with this kernel, after reboot the bios beeps and the > hardware time and date stands at the beginning, so I have to setup > manually to continue the post process. I think, gcc pre3.1 miscompiles > something in the kernel. >
Here is a test program I would like everybody to try. It is a module but is not intended to actually be implimented in the kernel as a module once eveybody finds out that it will reliably cold-start even a SMP machine. This is for Intel CPUs only.
The purpose of the module is to execute two simple CPU instructions in kernel mode. This forces a processor reset, just like hitting the reset button.
There are two scripts that you should look at because you might want to go to single-user mode first and unmount your disk(s) if your `kill -1` command kills you as well as everybody else.
I think all the complex reboot stuff in the kernel can be removed and the simple two-line assembly substituted.
If anybody finds that executing the 'open()' of this test module does not cause a processor reset in which a cold boot is forced, please let me know.
Once most everybody has faith that this will produce a clean reboot, somebody, maybe Allan can use it to replace the reboot code in the kernel.
The code works by disabling paging while executing code where there is not a 1:1 physical/virtual page mapping. I have never found a system, even one with two CPUs that did not instantly reset.
Cheers, Dick Johnson
Penguin : Linux version 2.4.1 on an i686 machine (797.90 BogoMips).
I was going to compile a list of innovations that could be attributed to Microsoft. Once I realized that Ctrl-Alt-Del was handled in the BIOS, I found that there aren't any.
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