2046482e77
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.
43 lines
1.3 KiB
C++
43 lines
1.3 KiB
C++
/*******************************************************************************
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Copyright(C) Jonas 'Sortie' Termansen 2012.
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This file is part of Sortix.
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Sortix is free software: you can redistribute it and/or modify it under the
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terms of the GNU General Public License as published by the Free Software
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Foundation, either version 3 of the License, or (at your option) any later
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version.
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Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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details.
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You should have received a copy of the GNU General Public License along with
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Sortix. If not, see <http://www.gnu.org/licenses/>.
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x86-family/msr.h
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Functions to manipulate Model Specific Registers.
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*******************************************************************************/
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#ifndef SORTIX_X86_FAMILY_MSR_H
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#define SORTIX_X86_FAMILY_MSR_H
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namespace Sortix {
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namespace MSR {
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bool IsPATSupported();
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void InitializePAT();
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bool IsMTRRSupported();
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const char* SetupMTRRForWC(addr_t base, size_t size, int* ret = NULL);
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void EnableMTRR(int mtrr);
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void DisableMTRR(int mtrr);
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void CopyMTRR(int dst, int src);
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} // namespace MSR
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} // namespace Sortix
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#endif
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