[geeks] Upgrading/troubleshooting Athlon64 laptop (was Policy for system...)

[der Mouse]

> I have here an Athlon64 laptop [...] CPU thermal shutdown [...]

> It will quite happily sit at a grub boot prompt, waiting for input,
> indefinitely.  It will boot memtest86+ and run it quite happily, and
> so far without any sign of memory errors.  But start to boot a Linux
> kernel [...] Windows XP SP3 [...] the sysrescueCD [...and it locks up
> seconds into the boot].

> Second ... anyone have any theories as to what might be the boot-time
> problem?  [...]

My first suspicion was that it's thermal, that all the "works" cases
exercise the CPU very lightly.  But, on reflection, that doesn't really
fit; booting is also a light-load activity.

> The fact that the boot-time lockup appears to be OS-independent
> suggests it's a hardware problem ... but then again, the fact that
> it'll happily boot and run memtest86+ suggests it's a software
> problem.

Unless memtest86+ simply doesn't poke the hardware that's at fault.
This is my current favoured theory: that something (disk interface? one
of the many bus-to-bus bridges modern machines have?) has gone flaky,
for reasons we can speculate about but which don't really matter.  But,
as long as it's hardware memtest86+ doesn't use and thus doesn't touch,
and is hardware the BIOS doesn't use for booting, this fits.

The latter eliminates a few things, but not all that much; for example,
it might not be the IDE interface, but it could be the DMA engine for
the IDE interface (booting often enough does PIO for everything, as
it's not performance-critical and PIO is easier and smaller to code).

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