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aedrix-kernel/arch/i386/kernel/multiboot.c

65 lines
2.1 KiB
C

/*
Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
This file is part of Aedrix.
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 2 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, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <arch/multiboot.h>
#include <mmu.h>
struct multiboot_mmap {
unsigned int size;
unsigned int base_addr_low, base_addr_high;
unsigned int length_low, length_high;
unsigned int type;
};
extern multiboot_info_t* multiboot_mbd;
extern uint32 multiboot_magic;
int detect_memory_mmap() {
struct multiboot_mmap* mmap = (struct multiboot_mmap*)multiboot_mbd->mmap_addr;
int found_region = 0;
while ((char*)mmap < (char*)multiboot_mbd->mmap_addr + multiboot_mbd->mmap_length) {
if (mmap->base_addr_high || mmap->length_high)
return -1;
if (mmap->type == 0x1) { /* ignore non-usable memory */
declare_memory_region((void*)mmap->base_addr_low,
(void*)(mmap->base_addr_low + mmap->length_low));
found_region = 1;
}
mmap = (struct multiboot_mmap*) ((unsigned int)mmap + mmap->size + sizeof(unsigned int));
}
return !found_region;
}
int detect_memory_contiguous() {
declare_memory_region((void*)0x0, (void*)((uint32)multiboot_mbd->mem_lower * 1024));
declare_memory_region((void*)0x1000000, (void*)((uint32)multiboot_mbd->mem_upper*1024 + 0x100000));
return 0;
}
int detect_memory() {
if (multiboot_mbd->flags & (1<<6))
return detect_memory_mmap();
else if (multiboot_mbd->flags & (1<<0))
return detect_memory_contiguous();
return -1;
}