1 /*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 /*
28 * Obtain memory configuration information from the BIOS
29 */
30 #include <stand.h>
31 #include <machine/pc/bios.h>
32 #include "bootstrap.h"
33 #include "libi386.h"
34 #include "btxv86.h"
35 #include "smbios.h"
36
37 vm_offset_t memtop, memtop_copyin, high_heap_base;
38 uint32_t bios_basemem, bios_extmem, high_heap_size;
39
40 static struct bios_smap_xattr smap;
41
42 /*
43 * Used to track which method was used to set BIOS memory
44 * regions.
45 */
46 static uint8_t b_bios_probed;
47 #define B_BASEMEM_E820 0x1
48 #define B_BASEMEM_12 0x2
49 #define B_EXTMEM_E820 0x4
50 #define B_EXTMEM_E801 0x8
51 #define B_EXTMEM_8800 0x10
52
53 /*
54 * The minimum amount of memory to reserve in bios_extmem for the heap.
55 */
56 #define HEAP_MIN (64 * 1024 * 1024)
57
58 /*
59 * Products in this list need quirks to detect
60 * memory correctly. You need both maker and product as
61 * reported by smbios.
62 */
63 /* e820 might not return useful extended memory */
64 #define BQ_DISTRUST_E820_EXTMEM 0x1
65 struct bios_getmem_quirks {
66 const char *bios_vendor;
67 const char *maker;
68 const char *product;
69 int quirk;
70 };
71
72 static struct bios_getmem_quirks quirks[] = {
73 {"coreboot", "Acer", "Peppy", BQ_DISTRUST_E820_EXTMEM},
74 {"coreboot", "Dell", "Wolf", BQ_DISTRUST_E820_EXTMEM},
75 {NULL, NULL, NULL, 0}
76 };
77
78 static int
bios_getquirks(void)79 bios_getquirks(void)
80 {
81 int i;
82
83 for (i = 0; quirks[i].quirk != 0; ++i) {
84 if (smbios_match(quirks[i].bios_vendor, quirks[i].maker,
85 quirks[i].product))
86 return (quirks[i].quirk);
87 }
88
89 return (0);
90 }
91
92 void
bios_getmem(void)93 bios_getmem(void)
94 {
95 uint64_t size;
96
97 /* Parse system memory map */
98 v86.ebx = 0;
99 do {
100 v86.ctl = V86_FLAGS;
101 v86.addr = 0x15; /* int 0x15 function 0xe820 */
102 v86.eax = 0xe820;
103 v86.ecx = sizeof(struct bios_smap_xattr);
104 v86.edx = SMAP_SIG;
105 v86.es = VTOPSEG(&smap);
106 v86.edi = VTOPOFF(&smap);
107 v86int();
108 if ((V86_CY(v86.efl)) || (v86.eax != SMAP_SIG))
109 break;
110 /* look for a low-memory segment that's large enough */
111 if ((smap.type == SMAP_TYPE_MEMORY) && (smap.base == 0) &&
112 (smap.length >= (512 * 1024))) {
113 bios_basemem = smap.length;
114 b_bios_probed |= B_BASEMEM_E820;
115 }
116
117 /* look for the first segment in 'extended' memory */
118 if ((smap.type == SMAP_TYPE_MEMORY) &&
119 (smap.base == 0x100000) &&
120 !(bios_getquirks() & BQ_DISTRUST_E820_EXTMEM)) {
121 bios_extmem = smap.length;
122 b_bios_probed |= B_EXTMEM_E820;
123 }
124
125 /*
126 * Look for the highest segment in 'extended' memory beyond
127 * 1MB but below 4GB.
128 */
129 if ((smap.type == SMAP_TYPE_MEMORY) &&
130 (smap.base > 0x100000) &&
131 (smap.base < 0x100000000ull)) {
132 size = smap.length;
133
134 /*
135 * If this segment crosses the 4GB boundary,
136 * truncate it.
137 */
138 if (smap.base + size > 0x100000000ull)
139 size = 0x100000000ull - smap.base;
140
141 /*
142 * To make maximum space for the kernel and the modules,
143 * set heap to use highest HEAP_MIN bytes below 4GB.
144 */
145 if (high_heap_base < smap.base && size >= HEAP_MIN) {
146 high_heap_base = smap.base + size - HEAP_MIN;
147 high_heap_size = HEAP_MIN;
148 }
149 }
150 } while (v86.ebx != 0);
151
152 /* Fall back to the old compatibility function for base memory */
153 if (bios_basemem == 0) {
154 v86.ctl = 0;
155 v86.addr = 0x12; /* int 0x12 */
156 v86int();
157
158 bios_basemem = (v86.eax & 0xffff) * 1024;
159 b_bios_probed |= B_BASEMEM_12;
160 }
161
162 /*
163 * Fall back through several compatibility functions for extended
164 * memory.
165 */
166 if (bios_extmem == 0) {
167 v86.ctl = V86_FLAGS;
168 v86.addr = 0x15; /* int 0x15 function 0xe801 */
169 v86.eax = 0xe801;
170 v86int();
171 if (!(V86_CY(v86.efl))) {
172 /*
173 * Clear high_heap; it may end up overlapping
174 * with the segment we're determining here.
175 * Let the default "steal stuff from top of
176 * bios_extmem" code below pick up on it.
177 */
178 high_heap_size = 0;
179 high_heap_base = 0;
180
181 /*
182 * %cx is the number of 1KiB blocks between 1..16MiB.
183 * It can only be up to 0x3c00; if it's smaller then
184 * there's a PC AT memory hole so we can't treat
185 * it as contiguous.
186 */
187 bios_extmem = (v86.ecx & 0xffff) * 1024;
188 if (bios_extmem == (1024 * 0x3c00))
189 bios_extmem += (v86.edx & 0xffff) * 64 * 1024;
190
191 /* truncate bios_extmem */
192 if (bios_extmem > 0x3ff00000)
193 bios_extmem = 0x3ff00000;
194
195 b_bios_probed |= B_EXTMEM_E801;
196 }
197 }
198 if (bios_extmem == 0) {
199 v86.ctl = 0;
200 v86.addr = 0x15; /* int 0x15 function 0x88 */
201 v86.eax = 0x8800;
202 v86int();
203 bios_extmem = (v86.eax & 0xffff) * 1024;
204 b_bios_probed |= B_EXTMEM_8800;
205 }
206
207 /* Set memtop to actual top of memory */
208 if (high_heap_size != 0) {
209 memtop = memtop_copyin = high_heap_base;
210 } else {
211 memtop = memtop_copyin = 0x100000 + bios_extmem;
212 }
213
214 /*
215 * If we have extended memory and did not find a suitable heap
216 * region in the SMAP, use the last HEAP_MIN of 'extended' memory as a
217 * high heap candidate.
218 */
219 if (bios_extmem >= HEAP_MIN && high_heap_size < HEAP_MIN) {
220 high_heap_size = HEAP_MIN;
221 high_heap_base = memtop - HEAP_MIN;
222 memtop = memtop_copyin = high_heap_base;
223 }
224 }
225
226 static int
command_biosmem(int argc,char * argv[])227 command_biosmem(int argc, char *argv[])
228 {
229 int bq = bios_getquirks();
230
231 printf("bios_basemem: 0x%llx\n", (unsigned long long)bios_basemem);
232 printf("bios_extmem: 0x%llx\n", (unsigned long long)bios_extmem);
233 printf("memtop: 0x%llx\n", (unsigned long long)memtop);
234 printf("high_heap_base: 0x%llx\n", (unsigned long long)high_heap_base);
235 printf("high_heap_size: 0x%llx\n", (unsigned long long)high_heap_size);
236 printf("bios_quirks: 0x%02x", bq);
237 if (bq & BQ_DISTRUST_E820_EXTMEM)
238 printf(" BQ_DISTRUST_E820_EXTMEM");
239 printf("\n");
240 printf("b_bios_probed: 0x%02x", (int)b_bios_probed);
241 if (b_bios_probed & B_BASEMEM_E820)
242 printf(" B_BASEMEM_E820");
243 if (b_bios_probed & B_BASEMEM_12)
244 printf(" B_BASEMEM_12");
245 if (b_bios_probed & B_EXTMEM_E820)
246 printf(" B_EXTMEM_E820");
247 if (b_bios_probed & B_EXTMEM_E801)
248 printf(" B_EXTMEM_E801");
249 if (b_bios_probed & B_EXTMEM_8800)
250 printf(" B_EXTMEM_8800");
251 printf("\n");
252
253 return (CMD_OK);
254 }
255
256 COMMAND_SET(biosmem, "biosmem", "show BIOS memory setup", command_biosmem);
257