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// Support for building memory maps suitable for int 15 e820 calls.
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// Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net>
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// This file may be distributed under the terms of the GNU LGPLv3 license.
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#include "memmap.h" // struct e820entry
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#include "util.h" // dprintf.h
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#include "biosvar.h" // SET_EBDA
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/****************************************************************
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****************************************************************/
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// Remove an entry from the e820_list.
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memmove(&e820_list[i], &e820_list[i+1]
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, sizeof(e820_list[0]) * (e820_count - i));
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// Insert an entry in the e820_list at the given position.
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insert_e820(int i, u64 start, u64 size, u32 type)
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if (e820_count >= CONFIG_MAX_E820) {
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memmove(&e820_list[i+1], &e820_list[i]
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, sizeof(e820_list[0]) * (e820_count - i));
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struct e820entry *e = &e820_list[i];
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// Show the current e820_list.
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dprintf(1, "e820 map has %d items:\n", e820_count);
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for (i=0; i<e820_count; i++) {
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struct e820entry *e = &e820_list[i];
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u64 e_end = e->start + e->size;
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dprintf(1, " %d: %08x%08x - %08x%08x = %d\n", i
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, (u32)(e->start >> 32), (u32)e->start
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, (u32)(e_end >> 32), (u32)e_end
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// Add a new entry to the list. This scans for overlaps and keeps the
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add_e820(u64 start, u64 size, u32 type)
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dprintf(8, "Add to e820 map: %08x %08x %d\n", (u32)start, (u32)size, type);
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// Huh? Nothing to do.
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// Find position of new item (splitting existing item if needed).
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u64 end = start + size;
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for (i=0; i<e820_count; i++) {
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struct e820entry *e = &e820_list[i];
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u64 e_end = e->start + e->size;
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// Found position - check if an existing item needs to be split.
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if (start > e->start) {
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if (type == e->type) {
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// Same type - merge them.
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size += start - e->start;
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// Split existing item.
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e->size = start - e->start;
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insert_e820(i, end, e_end - end, e->type);
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// Remove/adjust existing items that are overlapping.
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while (i<e820_count) {
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struct e820entry *e = &e820_list[i];
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u64 e_end = e->start + e->size;
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// Existing item completely overlapped - remove it.
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// Not completely overlapped - adjust its start.
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e->size = e_end - end;
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if (type == e->type) {
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// Same type - merge them.
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if (type != E820_HOLE)
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insert_e820(i, start, size, type);
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// Prep for memmap stuff - init bios table locations.
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// Report on final memory locations.
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memmap_finalize(void)