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sortix--sortix/sortix/x86-family/msr.h
Jonas 'Sortie' Termansen 2046482e77 Added support for MSRs, PAT and MTRRs.
This provides control over the caching of memory, which makes write-combined
IO possible. Graphics drivers can use this to transfer data at a much higher
rate to the video memory.

The implementation is a bit hacky but it'll do for now. It provides enough
support for the experimental VBE driver to work on the real computers I
tested it on, even if the BIOS uses screwed up default MTRRs.

The virtual memory layer now automatically uses the PAT feature if available
but in a backwards compatible manner and otherwise just tries to approximate
PAT features if they are asked for.
2012-07-01 00:55:36 +02:00

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C++

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2012.
This file is part of Sortix.
Sortix is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details.
You should have received a copy of the GNU General Public License along with
Sortix. If not, see <http://www.gnu.org/licenses/>.
x86-family/msr.h
Functions to manipulate Model Specific Registers.
*******************************************************************************/
#ifndef SORTIX_X86_FAMILY_MSR_H
#define SORTIX_X86_FAMILY_MSR_H
namespace Sortix {
namespace MSR {
bool IsPATSupported();
void InitializePAT();
bool IsMTRRSupported();
const char* SetupMTRRForWC(addr_t base, size_t size, int* ret = NULL);
void EnableMTRR(int mtrr);
void DisableMTRR(int mtrr);
void CopyMTRR(int dst, int src);
} // namespace MSR
} // namespace Sortix
#endif