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/*
* Copyright (c) 2010-2016 Richard Braun.
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef X86_BIOSMEM_H
#define X86_BIOSMEM_H
#include <stdbool.h>
#include <kern/init.h>
#include <machine/multiboot.h>
#include <machine/types.h>
/*
* BIOS Data Area.
*/
#define BIOSMEM_BDA_ADDR 0x400
#define BIOSMEM_BDA_SIZE 0x100
/*
* Address where the address of the Extended BIOS Data Area segment can be
* found.
*/
#define BIOSMEM_EBDA_PTR 0x40e
/*
* Significant low memory addresses.
*
* The first 64 KiB are reserved for various reasons (e.g. to preserve BIOS
* data and to work around data corruption on some hardware).
*/
#define BIOSMEM_BASE 0x010000
#define BIOSMEM_BASE_END 0x0a0000
#define BIOSMEM_EXT_ROM 0x0e0000
#define BIOSMEM_ROM 0x0f0000
#define BIOSMEM_END 0x100000
/*
* Report reserved addresses to the biosmem module.
*
* Once all boot data have been registered, the user can set up the
* early page allocator.
*
* If the range is marked temporary, it will be unregistered once
* the boot data have been saved/consumed so that their backing
* pages are loaded into the VM system.
*
* This function is called before paging is enabled.
*/
void biosmem_register_boot_data(phys_addr_t start, phys_addr_t end,
bool temporary);
/*
* Initialize the early page allocator.
*
* This function uses the memory map provided by the boot loader along
* with the registered boot data addresses to set up a heap of free pages
* of physical memory.
*
* This function is called before paging is enabled.
*/
void biosmem_bootstrap(const struct multiboot_raw_info *mbi);
/*
* Allocate contiguous physical pages during bootstrap.
*
* The pages returned are guaranteed to be part of the direct physical
* mapping when paging is enabled.
*
* This function should only be used to allocate initial page table pages.
* Those pages are later loaded into the VM system (as reserved pages)
* which means they can be freed like other regular pages. Users should
* fix up the type of those pages once the VM system is initialized.
*
* This function is called before paging is enabled.
*/
void * biosmem_bootalloc(unsigned int nr_pages);
/*
* Return a pointer to a copy of the BIOS Data Area.
*
* The region denoted by the returned address is of size BIOSMEM_BDA_SIZE,
* and is only valid during initialization.
*/
const void * biosmem_get_bda(void);
/*
* Return the limit of physical memory that can be directly mapped.
*/
phys_addr_t biosmem_directmap_end(void);
/*
* This init operation provides :
* - heaps of physical memory are loaded by the VM system
*/
INIT_OP_DECLARE(biosmem_setup);
#endif /* X86_BIOSMEM_H */
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