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 #include <sys/cdefs.h>
28
29 /*
30 * Obtain memory configuration information from the BIOS
31 */
32 #include <stand.h>
33 #include <machine/pc/bios.h>
34 #include "bootstrap.h"
35 #include "libi386.h"
36 #include "btxv86.h"
37 #include "smbios.h"
38
39 vm_offset_t memtop, memtop_copyin, high_heap_base;
40 uint32_t bios_basemem, bios_extmem, high_heap_size;
41
42 static struct bios_smap_xattr smap;
43
44 /*
45 * Used to track which method was used to set BIOS memory
46 * regions.
47 */
48 static uint8_t b_bios_probed;
49 #define B_BASEMEM_E820 0x1
50 #define B_BASEMEM_12 0x2
51 #define B_EXTMEM_E820 0x4
52 #define B_EXTMEM_E801 0x8
53 #define B_EXTMEM_8800 0x10
54
55 /*
56 * The minimum amount of memory to reserve in bios_extmem for the heap.
57 */
58 #define HEAP_MIN (64 * 1024 * 1024)
59
60 /*
61 * Products in this list need quirks to detect
62 * memory correctly. You need both maker and product as
63 * reported by smbios.
64 */
65 /* e820 might not return useful extended memory */
66 #define BQ_DISTRUST_E820_EXTMEM 0x1
67 struct bios_getmem_quirks {
68 const char *bios_vendor;
69 const char *maker;
70 const char *product;
71 int quirk;
72 };
73
74 static struct bios_getmem_quirks quirks[] = {
75 {"coreboot", "Acer", "Peppy", BQ_DISTRUST_E820_EXTMEM},
76 {NULL, NULL, NULL, 0}
77 };
78
79 static int
bios_getquirks(void)80 bios_getquirks(void)
81 {
82 int i;
83
84 for (i = 0; quirks[i].quirk != 0; ++i) {
85 if (smbios_match(quirks[i].bios_vendor, quirks[i].maker,
86 quirks[i].product))
87 return (quirks[i].quirk);
88 }
89
90 return (0);
91 }
92
93 void
bios_getmem(void)94 bios_getmem(void)
95 {
96 uint64_t size;
97
98 /* Parse system memory map */
99 v86.ebx = 0;
100 do {
101 v86.ctl = V86_FLAGS;
102 v86.addr = 0x15; /* int 0x15 function 0xe820 */
103 v86.eax = 0xe820;
104 v86.ecx = sizeof (struct bios_smap_xattr);
105 v86.edx = SMAP_SIG;
106 v86.es = VTOPSEG(&smap);
107 v86.edi = VTOPOFF(&smap);
108 v86int();
109 if ((V86_CY(v86.efl)) || (v86.eax != SMAP_SIG))
110 break;
111 /* look for a low-memory segment that's large enough */
112 if ((smap.type == SMAP_TYPE_MEMORY) && (smap.base == 0) &&
113 (smap.length >= (512 * 1024))) {
114 bios_basemem = smap.length;
115 b_bios_probed |= B_BASEMEM_E820;
116 }
117
118 /* look for the first segment in 'extended' memory */
119 if ((smap.type == SMAP_TYPE_MEMORY) &&
120 (smap.base == 0x100000) &&
121 !(bios_getquirks() & BQ_DISTRUST_E820_EXTMEM)) {
122 bios_extmem = smap.length;
123 b_bios_probed |= B_EXTMEM_E820;
124 }
125
126 /*
127 * Look for the highest segment in 'extended' memory beyond
128 * 1MB but below 4GB.
129 */
130 if ((smap.type == SMAP_TYPE_MEMORY) &&
131 (smap.base > 0x100000) &&
132 (smap.base < 0x100000000ull)) {
133 size = smap.length;
134
135 /*
136 * If this segment crosses the 4GB boundary,
137 * truncate it.
138 */
139 if (smap.base + size > 0x100000000ull)
140 size = 0x100000000ull - smap.base;
141
142 /*
143 * To make maximum space for the kernel and the modules,
144 * set heap to use highest HEAP_MIN bytes below 4GB.
145 */
146 if (high_heap_base < smap.base && size >= HEAP_MIN) {
147 high_heap_base = smap.base + size - HEAP_MIN;
148 high_heap_size = HEAP_MIN;
149 }
150 }
151 } while (v86.ebx != 0);
152
153 /* Fall back to the old compatibility function for base memory */
154 if (bios_basemem == 0) {
155 v86.ctl = 0;
156 v86.addr = 0x12; /* int 0x12 */
157 v86int();
158
159 bios_basemem = (v86.eax & 0xffff) * 1024;
160 b_bios_probed |= B_BASEMEM_12;
161 }
162
163 /*
164 * Fall back through several compatibility functions for extended
165 * memory.
166 */
167 if (bios_extmem == 0) {
168 v86.ctl = V86_FLAGS;
169 v86.addr = 0x15; /* int 0x15 function 0xe801 */
170 v86.eax = 0xe801;
171 v86int();
172 if (!(V86_CY(v86.efl))) {
173 /*
174 * Clear high_heap; it may end up overlapping
175 * with the segment we're determining here.
176 * Let the default "steal stuff from top of
177 * bios_extmem" code below pick up on it.
178 */
179 high_heap_size = 0;
180 high_heap_base = 0;
181
182 /*
183 * %cx is the number of 1KiB blocks between 1..16MiB.
184 * It can only be up to 0x3c00; if it's smaller then
185 * there's a PC AT memory hole so we can't treat
186 * it as contiguous.
187 */
188 bios_extmem = (v86.ecx & 0xffff) * 1024;
189 if (bios_extmem == (1024 * 0x3c00))
190 bios_extmem += (v86.edx & 0xffff) * 64 * 1024;
191
192 /* truncate bios_extmem */
193 if (bios_extmem > 0x3ff00000)
194 bios_extmem = 0x3ff00000;
195
196 b_bios_probed |= B_EXTMEM_E801;
197 }
198 }
199 if (bios_extmem == 0) {
200 v86.ctl = 0;
201 v86.addr = 0x15; /* int 0x15 function 0x88 */
202 v86.eax = 0x8800;
203 v86int();
204 bios_extmem = (v86.eax & 0xffff) * 1024;
205 b_bios_probed |= B_EXTMEM_8800;
206 }
207
208 /* Set memtop to actual top of memory */
209 if (high_heap_size != 0) {
210 memtop = memtop_copyin = high_heap_base;
211 } else {
212 memtop = memtop_copyin = 0x100000 + bios_extmem;
213 }
214
215 /*
216 * If we have extended memory and did not find a suitable heap
217 * region in the SMAP, use the last HEAP_MIN of 'extended' memory as a
218 * high heap candidate.
219 */
220 if (bios_extmem >= HEAP_MIN && high_heap_size < HEAP_MIN) {
221 high_heap_size = HEAP_MIN;
222 high_heap_base = memtop - HEAP_MIN;
223 memtop = memtop_copyin = high_heap_base;
224 }
225 }
226
227 static int
command_biosmem(int argc __unused,char * argv[]__unused)228 command_biosmem(int argc __unused, char *argv[] __unused)
229 {
230 int bq = bios_getquirks();
231
232 printf("bios_basemem: 0x%llx\n", (unsigned long long)bios_basemem);
233 printf("bios_extmem: 0x%llx\n", (unsigned long long)bios_extmem);
234 printf("memtop: 0x%llx\n", (unsigned long long)memtop);
235 printf("high_heap_base: 0x%llx\n", (unsigned long long)high_heap_base);
236 printf("high_heap_size: 0x%llx\n", (unsigned long long)high_heap_size);
237 printf("bios_quirks: 0x%02x", bq);
238 if (bq & BQ_DISTRUST_E820_EXTMEM)
239 printf(" BQ_DISTRUST_E820_EXTMEM");
240 printf("\n");
241 printf("b_bios_probed: 0x%02x", (int)b_bios_probed);
242 if (b_bios_probed & B_BASEMEM_E820)
243 printf(" B_BASEMEM_E820");
244 if (b_bios_probed & B_BASEMEM_12)
245 printf(" B_BASEMEM_12");
246 if (b_bios_probed & B_EXTMEM_E820)
247 printf(" B_EXTMEM_E820");
248 if (b_bios_probed & B_EXTMEM_E801)
249 printf(" B_EXTMEM_E801");
250 if (b_bios_probed & B_EXTMEM_8800)
251 printf(" B_EXTMEM_8800");
252 printf("\n");
253
254 return (CMD_OK);
255 }
256
257 COMMAND_SET(biosmem, "biosmem", "show BIOS memory setup", command_biosmem);
258