On Tue, Mar 8, 2011 at 18:23, Kevin O'Connor kevin@koconnor.net wrote:
On Tue, Mar 08, 2011 at 09:00:05AM -0800, Jordan Justen wrote:
Yes, the UEFI system is still in place. The UEFI part still handles the majority of platform init, and calls into the CSM at various points. The CSM returns back to UEFI for all CSM calls, except the legacy boot.
Is there a concise list of these various callbacks between UEFI and CSM?
If SeaBIOS just needs to be loaded up for legacy boots, that doesn't sound too difficult. However, if SeaBIOS would need to translate various BIOS calls into UEFI calls - that sounds like it could be complex.
A CSM does not really know about UEFI for the most part. Rather it carries out some tasks when request by the UEFI environment. The UEFI side still manages the high level boot flow (even for legacy boots). The CSM does not call into UEFI services, but just returns back to whoever invoked the CSM call.
The 16-bit CSM component interface is described in this file: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2/IntelFrameworkPkg/I...
The full CSM specification document is available here: http://www.intel.com/technology/framework/spec.htm
Thanks,
-Jordan