BIOS is responsible for enable or disable the HDA controller according to platform policy, which means you/OS couldn't see the pci device in pci bus at all if it's disabled by BIOS.
I suspect your case is like this. -----Original Message----- From: edk2-devel [mailto:[email protected]] On Behalf Of Gerard Bucas Sent: Tuesday, August 11, 2015 13:26 To: [email protected] Subject: [edk2] How to Add RealTek ALC262 Codec Support connected to Intel HDA bus Hi experts! We have an Intel Atom Baytrail SoC (E3845) based board which has a Realtek ALC262 audio codec connected to the Intel HAD bus. We used the 0.82 MinnowBoard MAX firmware as our starting "BIOS" and modified it to support SODIMM's etc. We are using yocto built linux and Ubuntu as test OS's. Both run well & are stable. HDA audio works (directed to HDMI). However, our linux kernel does not "see/detect" the Realtek AudIo codec on this board, whereas it does on other boards that have a similar setup using a different BIOS. So I need some help with understanding how/what we need to modify in the minnowMax firmware to support this ALC262 codec connected in this way. I am a little confused as to what the BIOS/firmware does versus what the linux kernel does to detect and initialize the device. I would have thought that all detection and initialization of the ALC262 is done by the linux kernel (assuming the correct drivers are included - which is the case) as opposed to the (edk2/MinnowMAX based uefi firmware/BIOS)? So it seems I am missing some fundamental concept in understanding "who does what" (firmware versus OS kernel)? Would really appreciate some input on this and some pointers as to how to add the right support at the right level! Thanks & Regards Gerard _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
