The exact recipe will be a closely guarded trade secret for manufacturers but certain things hold true. Chipworks might give you some background that may help for specific cameras (or it might not).
The actual light captured and charge generated will always be the same at the sensor. There are multiple points where the results can be adjusted.
CMOS sensors have an on-chip gain control / amplifier which makes adjustments during the readout (CCD's don't).
There can a separate amplification stage en-route to the ADC. Necessary for CCD but some CMOS systems have been seen to do this too.
Finally a third layer of digital adjustment may be applied.