2010/11/4 Rajat Sharma <fs.rajat@xxxxxxxxx>: > As I can remember, Linux uses BIOS only at the bootup time, after that on a > running kernel, there is no role of BIOS routines. Please refer to > Understanding Linux Kernel for specific details. It also has one appendix on > Linux Boot-up sequence which depends on BIOS. Linux has its own drivers for > controlling IOAPIC and PCI drivers etc. > Rajat Rajat, At least for the storage stack that is misleading because although BIOS routines are not used, that does not mean the BIOS has no impact on the kernel functionality. There are configuration choices made in the bios that have a fundamental impact on the kernels operation: eg. AHCI operation vs. Legacy JBOD vs. fakeraid etc. fundamentally impact how the hardware work and actually cause entirely different ATA drivers to be used because these selections impact the PCI-ID reported by the hardware. Then there are more detailed tuning parameters that are read by the drivers to tune performance of the individual ATA drivers. For these parameters, the storage drivers attempt to determine them on their own, but in several scenarios the ATA controller is simply better able to make an informed guess and the kernel simply reads those tuning parameters and uses them. Greg -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
