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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//
3// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
4//
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
7#include "memmap.h" // struct e820entry
8#include "util.h" // dprintf.h
Kevin O'Connor9521e262008-07-04 13:04:29 -04009#include "biosvar.h" // SET_EBDA
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040010
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040011// Remove an entry from the e820_list.
12static void
13remove_e820(int i)
14{
15 e820_count--;
16 memmove(&e820_list[i], &e820_list[i+1]
17 , sizeof(e820_list[0]) * (e820_count - i));
18}
19
20// Insert an entry in the e820_list at the given position.
21static void
22insert_e820(int i, u64 start, u64 size, u32 type)
23{
Kevin O'Connord995b3d2008-11-08 13:05:27 -050024 if (e820_count >= CONFIG_MAX_E820) {
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040025 dprintf(1, "Overflowed e820 list!\n");
26 return;
27 }
28
29 memmove(&e820_list[i+1], &e820_list[i]
30 , sizeof(e820_list[0]) * (e820_count - i));
31 e820_count++;
32 struct e820entry *e = &e820_list[i];
33 e->start = start;
34 e->size = size;
35 e->type = type;
36}
37
38// Show the current e820_list.
39static void
40dump_map()
41{
42 dprintf(1, "e820 map has %d items:\n", e820_count);
43 int i;
44 for (i=0; i<e820_count; i++) {
45 struct e820entry *e = &e820_list[i];
46 u64 e_end = e->start + e->size;
47 dprintf(1, " %d: %x%x - %x%x = %d\n", i
48 , (u32)(e->start >> 32), (u32)e->start
49 , (u32)(e_end >> 32), (u32)e_end
50 , e->type);
51 }
52}
53
54// Add a new entry to the list. This scans for overlaps and keeps the
55// list sorted.
56void
57add_e820(u64 start, u64 size, u32 type)
58{
59 dprintf(8, "Add to e820 map: %x %x %d\n", (u32)start, (u32)size, type);
60
61 if (! size)
62 // Huh? Nothing to do.
63 return;
64
65 u64 end = start + size;
66 int i;
67 for (i=0; i<e820_count; i++) {
68 struct e820entry *e = &e820_list[i];
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -040069 if (end < e->start)
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040070 // Simple insertion point.
71 break;
72 u64 e_end = e->start + e->size;
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -040073 if (start > e_end)
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040074 // No overlap.
75 continue;
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -040076 // New item overlaps (or borders) an existing one.
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040077 if (start > e->start) {
78 e->size = start - e->start;
79 i++;
80 if (end < e_end)
81 // Need to split existing item
82 insert_e820(i, end, e_end - end, e->type);
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -040083 if (type == e->type) {
84 // Same type - merge them.
85 size += start - e->start;
86 start = e->start;
87 i--;
88 remove_e820(i);
89 }
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040090 }
Kevin O'Connorb8d7a472008-06-21 11:43:32 -040091 if (type != E820_HOLE) {
92 insert_e820(i, start, size, type);
93 i++;
94 }
Kevin O'Connor59a23bb2008-06-08 23:09:42 -040095 // Remove all existing items that are completely overlapped.
96 while (i<e820_count) {
97 e = &e820_list[i];
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -040098 if (end < e->start)
99 // No overlap - done.
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400100 break;
101 e_end = e->start + e->size;
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -0400102 if (end >= e_end) {
103 // Existing item completely overlapped - remove it.
104 remove_e820(i);
105 continue;
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400106 }
Kevin O'Connoraa0c66d2008-06-11 21:23:24 -0400107 // Not completely overlapped - adjust its start.
108 e->start = end;
109 e->size = e_end - e->start;
110 if (type == e->type) {
111 // Same type - merge them.
112 (e-1)->size += e->size;
113 remove_e820(i);
114 }
115 break;
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400116 }
117 //dump_map();
118 return;
119 }
120 // Just insert item.
121 insert_e820(i, start, size, type);
122 //dump_map();
123}
124
Kevin O'Connor15b31652008-08-29 21:21:09 -0400125// Symbols defined in romlayout.S
126extern char freespace2_start, freespace2_end;
127
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400128u32 bios_table_cur_addr, bios_table_end_addr;
129
130// Prep for memmap stuff - init bios table locations.
131void
132memmap_setup()
133{
Kevin O'Connor2fda7cb2008-07-05 20:41:53 -0400134 bios_table_cur_addr = (u32)&freespace2_start;
135 bios_table_end_addr = (u32)&freespace2_end;
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400136 dprintf(1, "bios_table_addr: 0x%08x end=0x%08x\n",
137 bios_table_cur_addr, bios_table_end_addr);
Kevin O'Connord995b3d2008-11-08 13:05:27 -0500138
139 bios_table_cur_addr = ALIGN(bios_table_cur_addr, 4);
140 u32 msize = CONFIG_MAX_E820 * sizeof(e820_list[0]);
141 if (bios_table_cur_addr + msize > bios_table_end_addr) {
142 dprintf(1, "No room for e820 map!\n");
143 return;
144 }
Kevin O'Connoracf13742008-11-29 11:19:19 -0500145 e820_count = 0;
Kevin O'Connord995b3d2008-11-08 13:05:27 -0500146 e820_list = (void*)bios_table_cur_addr;
147 bios_table_cur_addr += msize;
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400148}
149
Kevin O'Connor9649a962008-12-10 20:53:35 -0500150// Report on final memory locations.
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400151void
152memmap_finalize()
153{
154 dump_map();
155
Kevin O'Connor15b31652008-08-29 21:21:09 -0400156 dprintf(1, "final bios_table_addr: 0x%08x (used %d%%)\n"
157 , bios_table_cur_addr
158 , (100 * (bios_table_cur_addr - (u32)&freespace2_start)
159 / ((u32)&freespace2_end - (u32)&freespace2_start)));
Kevin O'Connor0525d292008-07-04 06:18:30 -0400160 if (bios_table_cur_addr > bios_table_end_addr)
161 BX_PANIC("bios_table_end_addr overflow!\n");
Kevin O'Connor59a23bb2008-06-08 23:09:42 -0400162}