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sortix--sortix/sortix/x64/memorymanagement.cpp
Jonas 'Sortie' Termansen 7bc1fa259e Made Sortix compatible with gcc 4.6.1.
This commit fixes some instances of uninitialized memory.

In addition, the bootstrap tables for x64 are moved around a bit,
in this awful game of placing stuff where it won't collide with grub.
2011-12-25 00:10:56 +01:00

189 lines
5.7 KiB
C++

/******************************************************************************
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) 0x21000UL;
PML* const BOOTPML3 = (PML* const) 0x26000UL;
PML* const BOOTPML2 = (PML* const) 0x27000UL;
PML* const BOOTPML1 = (PML* const) 0x28000UL;
// 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) 0x29000UL;
PML* const FORKPML1 = (PML* const) 0x2A000UL;
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) 0x2B000UL;
PML* const PHYSPML2 = (PML* const) 0x2C000UL;
PML* const PHYSPML1 = (PML* const) 0x2D000UL;
PML* const PHYSPML0 = (PML* const) 0x2E000UL;
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)
}
// Please note that even if this function exists, you should still clean
// up the address space of a process _before_ calling
// DestroyAddressSpace. This is just a hack because it currently is
// impossible to clean up PLM1's using the MM api!
// ---
// TODO: This function is duplicated in {x86,x64}/memorymanagement.cpp!
// ---
void RecursiveFreeUserspacePages(size_t level, size_t offset)
{
PML* pml = PMLS[level] + offset;
for ( size_t i = 0; i < ENTRIES; i++ )
{
if ( !(pml->entry[i] & PML_PRESENT) ) { continue; }
if ( !(pml->entry[i] & PML_USERSPACE) ) { continue; }
if ( !(pml->entry[i] & PML_FORK) ) { continue; }
if ( level > 1 ) { RecursiveFreeUserspacePages(level-1, offset * ENTRIES + i); }
addr_t addr = pml->entry[i] & PML_ADDRESS;
pml->entry[i] = 0;
Page::Put(addr);
}
}
void DestroyAddressSpace()
{
// First let's do the safe part. Garbage collect any PML1/0's left
// behind by user-space. These are completely safe to delete.
RecursiveFreeUserspacePages(TOPPMLLEVEL, 0);
// TODO: Right now this just leaks memory.
// Switch to the address space from when the world was originally
// created. It should contain the kernel, the whole kernel, and
// nothing but the kernel.
PML* const BOOTPML4 = (PML* const) 0x21000UL;
SwitchAddressSpace((addr_t) BOOTPML4);
}
const size_t KERNEL_STACK_SIZE = 256UL * 1024UL;
const addr_t KERNEL_STACK_END = 0xFFFF800000001000UL;
const addr_t KERNEL_STACK_START = KERNEL_STACK_END + KERNEL_STACK_SIZE;
addr_t INITRD = KERNEL_STACK_START;
size_t initrdsize = 0;
const addr_t HEAPUPPER = 0xFFFFFE8000000000UL;
addr_t GetInitRD()
{
return INITRD;
}
size_t GetInitRDSize()
{
return initrdsize;
}
void RegisterInitRDSize(size_t size)
{
initrdsize = size;
}
addr_t GetHeapLower()
{
return Page::AlignUp(INITRD + initrdsize);
}
addr_t GetHeapUpper()
{
return HEAPUPPER;
}
addr_t GetKernelStack()
{
return KERNEL_STACK_START;
}
size_t GetKernelStackSize()
{
return KERNEL_STACK_SIZE;
}
}
}