1 // Support for building memory maps suitable for int 15 e820 calls.
3 // Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net>
5 // This file may be distributed under the terms of the GNU LGPLv3 license.
7 #include "memmap.h" // struct e820entry
8 #include "util.h" // dprintf.h
9 #include "biosvar.h" // SET_EBDA
12 /****************************************************************
14 ****************************************************************/
16 // Remove an entry from the e820_list.
21 memmove(&e820_list[i], &e820_list[i+1]
22 , sizeof(e820_list[0]) * (e820_count - i));
25 // Insert an entry in the e820_list at the given position.
27 insert_e820(int i, u64 start, u64 size, u32 type)
29 if (e820_count >= CONFIG_MAX_E820) {
30 dprintf(1, "Overflowed e820 list!\n");
34 memmove(&e820_list[i+1], &e820_list[i]
35 , sizeof(e820_list[0]) * (e820_count - i));
37 struct e820entry *e = &e820_list[i];
43 // Show the current e820_list.
47 dprintf(1, "e820 map has %d items:\n", e820_count);
49 for (i=0; i<e820_count; i++) {
50 struct e820entry *e = &e820_list[i];
51 u64 e_end = e->start + e->size;
52 dprintf(1, " %d: %08x%08x - %08x%08x = %d\n", i
53 , (u32)(e->start >> 32), (u32)e->start
54 , (u32)(e_end >> 32), (u32)e_end
59 // Add a new entry to the list. This scans for overlaps and keeps the
62 add_e820(u64 start, u64 size, u32 type)
64 dprintf(8, "Add to e820 map: %08x %08x %d\n", (u32)start, (u32)size, type);
67 // Huh? Nothing to do.
70 // Find position of new item (splitting existing item if needed).
71 u64 end = start + size;
73 for (i=0; i<e820_count; i++) {
74 struct e820entry *e = &e820_list[i];
75 u64 e_end = e->start + e->size;
78 // Found position - check if an existing item needs to be split.
79 if (start > e->start) {
80 if (type == e->type) {
81 // Same type - merge them.
82 size += start - e->start;
85 // Split existing item.
86 e->size = start - e->start;
89 insert_e820(i, end, e_end - end, e->type);
94 // Remove/adjust existing items that are overlapping.
95 while (i<e820_count) {
96 struct e820entry *e = &e820_list[i];
100 u64 e_end = e->start + e->size;
102 // Existing item completely overlapped - remove it.
106 // Not completely overlapped - adjust its start.
108 e->size = e_end - end;
109 if (type == e->type) {
110 // Same type - merge them.
117 if (type != E820_HOLE)
118 insert_e820(i, start, size, type);
122 // Prep for memmap stuff - init bios table locations.
129 // Report on final memory locations.