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Kevin O'Connor59a23bb2008-06-08 23:09:42 -04001// Support for building memory maps suitable for int 15 e820 calls.
2//
Kevin O'Connor2929c352009-07-25 13:48:27 -04003// Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net>
Kevin O'Connor59a23bb2008-06-08 23:09:42 -04004//
Kevin O'Connorb1b7c2a2009-01-15 20:52:58 -05005// This file may be distributed under the terms of the GNU LGPLv3 license.
Kevin O'Connor59a23bb2008-06-08 23:09:42 -04006
Kevin O'Connore52ad392013-02-20 23:48:22 -05007#include "config.h" // BUILD_MAX_E820
Kevin O'Connor2d2fa312013-09-14 21:55:26 -04008#include "memmap.h" // struct e820entry
9#include "output.h" // dprintf
Kevin O'Connorfa9c66a2013-09-14 19:10:40 -040010#include "string.h" // memmove
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040011
Kevin O'Connor2929c352009-07-25 13:48:27 -040012
13/****************************************************************
14 * e820 memory map
15 ****************************************************************/
16
Kevin O'Connor89a2f962013-02-18 23:36:03 -050017// Info on e820 map location and size.
Kevin O'Connore52ad392013-02-20 23:48:22 -050018struct e820entry e820_list[BUILD_MAX_E820] VARFSEG;
Kevin O'Connor89a2f962013-02-18 23:36:03 -050019int e820_count VARFSEG;
20
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040021// Remove an entry from the e820_list.
22static void
23remove_e820(int i)
24{
25 e820_count--;
26 memmove(&e820_list[i], &e820_list[i+1]
27 , sizeof(e820_list[0]) * (e820_count - i));
28}
29
30// Insert an entry in the e820_list at the given position.
31static void
32insert_e820(int i, u64 start, u64 size, u32 type)
33{
Kevin O'Connore52ad392013-02-20 23:48:22 -050034 if (e820_count >= BUILD_MAX_E820) {
Kevin O'Connorcfdc13f2010-02-14 13:07:54 -050035 warn_noalloc();
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040036 return;
37 }
38
39 memmove(&e820_list[i+1], &e820_list[i]
40 , sizeof(e820_list[0]) * (e820_count - i));
41 e820_count++;
42 struct e820entry *e = &e820_list[i];
43 e->start = start;
44 e->size = size;
45 e->type = type;
46}
47
Ian Campbell1f4e8622011-05-13 16:30:55 +010048static const char *
49e820_type_name(u32 type)
50{
Kevin O'Connor7a08ae72012-03-14 21:11:39 -040051 switch (type) {
52 case E820_RAM: return "RAM";
53 case E820_RESERVED: return "RESERVED";
54 case E820_ACPI: return "ACPI";
55 case E820_NVS: return "NVS";
56 case E820_UNUSABLE: return "UNUSABLE";
57 case E820_HOLE: return "HOLE";
58 default: return "UNKNOWN";
59 }
Ian Campbell1f4e8622011-05-13 16:30:55 +010060}
61
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040062// Show the current e820_list.
63static void
Kevin O'Connor1ca05b02010-01-03 17:43:37 -050064dump_map(void)
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040065{
66 dprintf(1, "e820 map has %d items:\n", e820_count);
67 int i;
68 for (i=0; i<e820_count; i++) {
69 struct e820entry *e = &e820_list[i];
70 u64 e_end = e->start + e->size;
Kevin O'Connorc04090d2012-03-05 10:14:07 -050071 dprintf(1, " %d: %016llx - %016llx = %d %s\n", i
72 , e->start, e_end, e->type, e820_type_name(e->type));
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040073 }
74}
75
76// Add a new entry to the list. This scans for overlaps and keeps the
77// list sorted.
78void
79add_e820(u64 start, u64 size, u32 type)
80{
Kevin O'Connor91b53a72009-05-05 22:52:09 -040081 dprintf(8, "Add to e820 map: %08x %08x %d\n", (u32)start, (u32)size, type);
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040082
83 if (! size)
84 // Huh? Nothing to do.
85 return;
86
Kevin O'Connor5d8ec3e2009-02-27 20:19:27 -050087 // Find position of new item (splitting existing item if needed).
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040088 u64 end = start + size;
89 int i;
90 for (i=0; i<e820_count; i++) {
91 struct e820entry *e = &e820_list[i];
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040092 u64 e_end = e->start + e->size;
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -040093 if (start > e_end)
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040094 continue;
Kevin O'Connor5d8ec3e2009-02-27 20:19:27 -050095 // Found position - check if an existing item needs to be split.
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040096 if (start > e->start) {
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -040097 if (type == e->type) {
98 // Same type - merge them.
99 size += start - e->start;
100 start = e->start;
Kevin O'Connor1bedcc02009-04-26 21:25:53 -0400101 } else {
102 // Split existing item.
103 e->size = start - e->start;
104 i++;
105 if (e_end > end)
106 insert_e820(i, end, e_end - end, e->type);
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -0400107 }
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400108 }
Kevin O'Connor5d8ec3e2009-02-27 20:19:27 -0500109 break;
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400110 }
Kevin O'Connor5d8ec3e2009-02-27 20:19:27 -0500111 // Remove/adjust existing items that are overlapping.
112 while (i<e820_count) {
113 struct e820entry *e = &e820_list[i];
114 if (end < e->start)
115 // No overlap - done.
116 break;
117 u64 e_end = e->start + e->size;
118 if (end >= e_end) {
119 // Existing item completely overlapped - remove it.
120 remove_e820(i);
121 continue;
122 }
123 // Not completely overlapped - adjust its start.
124 e->start = end;
Kevin O'Connor1bedcc02009-04-26 21:25:53 -0400125 e->size = e_end - end;
Kevin O'Connor5d8ec3e2009-02-27 20:19:27 -0500126 if (type == e->type) {
127 // Same type - merge them.
Kevin O'Connor1bedcc02009-04-26 21:25:53 -0400128 size += e->size;
Kevin O'Connor5d8ec3e2009-02-27 20:19:27 -0500129 remove_e820(i);
130 }
131 break;
132 }
Kevin O'Connor1bedcc02009-04-26 21:25:53 -0400133 // Insert new item.
134 if (type != E820_HOLE)
135 insert_e820(i, start, size, type);
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400136 //dump_map();
137}
138
Kevin O'Connor9649a962008-12-10 20:53:35 -0500139// Report on final memory locations.
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400140void
Kevin O'Connord83c87b2013-01-21 01:14:12 -0500141memmap_prepboot(void)
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400142{
143 dump_map();
Kevin O'Connor2929c352009-07-25 13:48:27 -0400144}