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sortix--sortix/sortix/x64/memorymanagement.cpp

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/******************************************************************************
COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011.
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/>.
memorymanagement.cpp
Handles memory for the x64 architecture.
******************************************************************************/
#include "platform.h"
#include <libmaxsi/memory.h>
#include "multiboot.h"
#include "panic.h"
#include "../memorymanagement.h"
#include "x86-family/memorymanagement.h"
namespace Sortix
{
namespace Page
{
extern size_t stackused;
extern size_t stacklength;
}
namespace Memory
{
extern addr_t currentdir;
void InitCPU()
{
// The x64 boot code already set up virtual memory and identity
// mapped the first 2 MiB. This code finishes the job such that
// virtual memory is fully usable and manageable.
// boot.s already initialized everything from 0x1000UL to 0xE000UL
// to zeroes. Since these structures are already used, doing it here
// will be very dangerous.
PML* const BOOTPML4 = (PML* const) 0x01000UL;
PML* const BOOTPML3 = (PML* const) 0x06000UL;
PML* const BOOTPML2 = (PML* const) 0x07000UL;
PML* const BOOTPML1 = (PML* const) 0x08000UL;
// First order of business is to map the virtual memory structures
// to the pre-defined locations in the virtual address space.
addr_t flags = PML_PRESENT | PML_WRITABLE;
// Fractal map the PML1s.
BOOTPML4->entry[511] = (addr_t) BOOTPML4 | flags;
// Fractal map the PML2s.
BOOTPML4->entry[510] = (addr_t) BOOTPML3 | flags | PML_FORK;
BOOTPML3->entry[511] = (addr_t) BOOTPML4 | flags;
// Fractal map the PML3s.
BOOTPML3->entry[510] = (addr_t) BOOTPML2 | flags | PML_FORK;
BOOTPML2->entry[511] = (addr_t) BOOTPML4 | flags;
// Fractal map the PML4s.
BOOTPML2->entry[510] = (addr_t) BOOTPML1 | flags | PML_FORK;
BOOTPML1->entry[511] = (addr_t) BOOTPML4 | flags;
// Add some predefined room for forking address spaces.
PML* const FORKPML2 = (PML* const) 0x09000UL;
PML* const FORKPML1 = (PML* const) 0x0A000UL;
BOOTPML3->entry[0] = (addr_t) FORKPML2 | flags | PML_FORK;
BOOTPML2->entry[0] = (addr_t) FORKPML1 | flags | PML_FORK;
currentdir = (addr_t) BOOTPML4;
// The virtual memory structures are now available on the predefined
// locations. This means the virtual memory code is bootstrapped. Of
// course, we still have no physical page allocator, so that's the
// next step.
PML* const PHYSPML3 = (PML* const) 0x0B000UL;
PML* const PHYSPML2 = (PML* const) 0x0C000UL;
PML* const PHYSPML1 = (PML* const) 0x0D000UL;
PML* const PHYSPML0 = (PML* const) 0x0E000UL;
BOOTPML4->entry[509] = (addr_t) PHYSPML3 | flags;
PHYSPML3->entry[0] = (addr_t) PHYSPML2 | flags;
PHYSPML2->entry[0] = (addr_t) PHYSPML1 | flags;
PHYSPML1->entry[0] = (addr_t) PHYSPML0 | flags;
Page::stackused = 0;
Page::stacklength = 4096UL / sizeof(addr_t);
// The physical memory allocator should now be ready for use. Next
// up, the calling function will fill up the physical allocator with
// plenty of nice physical pages. (see Page::InitPushRegion)
}
}
}