http://gaugusch.at/kernel.shtml
has a kernel patch which allows you to override the DSDT
(Differentiated System Description Table) at boot time. However, this
does not work perfectly on the nx6125. The nx6125 has a SSDT (Secondary
System Description Table) which contains references to symbols in the
DSDT. Therefore, replacing the DSDT can break things unless the symbol
names match with the SSDT.
I ran into this problem when I installed a custom DSDT which was
derived by patching an older version of the BIOS. I had several "ACPI
Namespace" errors due to undefined references.