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) {
34 memmove(&e820_list[i+1], &e820_list[i]
35 , sizeof(e820_list[0]) * (e820_count - i));
37 struct e820entry *e = &e820_list[i];
44 e820_type_name(u32 type)
47 case E820_RAM: return "RAM";
48 case E820_RESERVED: return "RESERVED";
49 case E820_ACPI: return "ACPI";
50 case E820_NVS: return "NVS";
51 case E820_UNUSABLE: return "UNUSABLE";
52 case E820_HOLE: return "HOLE";
53 default: return "UNKNOWN";
57 // Show the current e820_list.
61 dprintf(1, "e820 map has %d items:\n", e820_count);
63 for (i=0; i<e820_count; i++) {
64 struct e820entry *e = &e820_list[i];
65 u64 e_end = e->start + e->size;
66 dprintf(1, " %d: %08x%08x - %08x%08x = %d %s\n", i
67 , (u32)(e->start >> 32), (u32)e->start
68 , (u32)(e_end >> 32), (u32)e_end
69 , e->type, e820_type_name(e->type));
73 // Add a new entry to the list. This scans for overlaps and keeps the
76 add_e820(u64 start, u64 size, u32 type)
78 dprintf(8, "Add to e820 map: %08x %08x %d\n", (u32)start, (u32)size, type);
81 // Huh? Nothing to do.
84 // Find position of new item (splitting existing item if needed).
85 u64 end = start + size;
87 for (i=0; i<e820_count; i++) {
88 struct e820entry *e = &e820_list[i];
89 u64 e_end = e->start + e->size;
92 // Found position - check if an existing item needs to be split.
93 if (start > e->start) {
94 if (type == e->type) {
95 // Same type - merge them.
96 size += start - e->start;
99 // Split existing item.
100 e->size = start - e->start;
103 insert_e820(i, end, e_end - end, e->type);
108 // Remove/adjust existing items that are overlapping.
109 while (i<e820_count) {
110 struct e820entry *e = &e820_list[i];
112 // No overlap - done.
114 u64 e_end = e->start + e->size;
116 // Existing item completely overlapped - remove it.
120 // Not completely overlapped - adjust its start.
122 e->size = e_end - end;
123 if (type == e->type) {
124 // Same type - merge them.
131 if (type != E820_HOLE)
132 insert_e820(i, start, size, type);
136 // Report on final memory locations.
138 memmap_finalize(void)