File: | src/sys/arch/amd64/stand/boot/../libsa/memprobe.c |
Warning: | line 242, column 17 Value stored to 'pm' during its initialization is never read |
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1 | /* $OpenBSD: memprobe.c,v 1.19 2021/01/28 18:54:52 deraadt Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 1997-1999 Michael Shalayeff |
5 | * Copyright (c) 1997-1999 Tobias Weingartner |
6 | * All rights reserved. |
7 | * |
8 | * Redistribution and use in source and binary forms, with or without |
9 | * modification, are permitted provided that the following conditions |
10 | * are met: |
11 | * 1. Redistributions of source code must retain the above copyright |
12 | * notice, this list of conditions and the following disclaimer. |
13 | * 2. Redistributions in binary form must reproduce the above copyright |
14 | * notice, this list of conditions and the following disclaimer in the |
15 | * documentation and/or other materials provided with the distribution. |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
19 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
27 | * SUCH DAMAGE. |
28 | * |
29 | */ |
30 | |
31 | #include <sys/param.h> |
32 | #include <machine/biosvar.h> |
33 | #include <dev/isa/isareg.h> |
34 | #include <stand/boot/bootarg.h> |
35 | #include "libsa.h" |
36 | |
37 | u_int cnvmem, extmem; /* XXX - compatibility */ |
38 | |
39 | bios_memmap_t bios_memmap[64]; /* This is easier */ |
40 | |
41 | /* |
42 | * Check gateA20 |
43 | * |
44 | * A sanity check. |
45 | */ |
46 | static __inline int |
47 | checkA20(void) |
48 | { |
49 | register char *p = (char *)0x100000; |
50 | register char *q = (char *)0x000000; |
51 | int st; |
52 | |
53 | /* Simple check */ |
54 | if (*p != *q) |
55 | return 1; |
56 | |
57 | /* Complex check */ |
58 | *p = ~(*p); |
59 | st = (*p != *q); |
60 | *p = ~(*p); |
61 | |
62 | return st; |
63 | } |
64 | |
65 | /* |
66 | * BIOS int 15, AX=E820 |
67 | * |
68 | * This is the "preferred" method. |
69 | */ |
70 | static __inline bios_memmap_t * |
71 | bios_E820(bios_memmap_t *mp) |
72 | { |
73 | int rc, off = 0, sig, gotcha = 0; |
74 | |
75 | do { |
76 | BIOS_regs.biosr_es = ((u_int)(mp) >> 4); |
77 | __asm volatile(DOINT(0x15)"int $0x20+(" "0x15" ")" "; setc %b1" |
78 | : "=a" (sig), "=d" (rc), "=b" (off) |
79 | : "0" (0xE820), "1" (0x534d4150), "b" (off), |
80 | "c" (sizeof(*mp)), "D" (((u_int)mp) & 0xf) |
81 | : "cc", "memory"); |
82 | off = BIOS_regs.biosr_bx; |
83 | |
84 | if (rc & 0xff || sig != 0x534d4150) |
85 | break; |
86 | gotcha++; |
87 | if (!mp->type) |
88 | mp->type = BIOS_MAP_RES0x02; |
89 | mp++; |
90 | } while (off); |
91 | |
92 | if (!gotcha) |
93 | return NULL((void *)0); |
94 | #ifdef DEBUG |
95 | printf("0x15[E820] "); |
96 | #endif |
97 | return mp; |
98 | } |
99 | |
100 | /* |
101 | * BIOS int 15, AX=8800 |
102 | * |
103 | * Only used if int 15, AX=E801 does not work. |
104 | * Machines with this are restricted to 64MB. |
105 | */ |
106 | static __inline bios_memmap_t * |
107 | bios_8800(bios_memmap_t *mp) |
108 | { |
109 | int rc, mem; |
110 | |
111 | __asm volatile(DOINT(0x15)"int $0x20+(" "0x15" ")" "; setc %b0" |
112 | : "=c" (rc), "=a" (mem) : "a" (0x8800)); |
113 | |
114 | if (rc & 0xff) |
115 | return NULL((void *)0); |
116 | #ifdef DEBUG |
117 | printf("0x15[8800] "); |
118 | #endif |
119 | /* Fill out a BIOS_MAP */ |
120 | mp->addr = 1024 * 1024; /* 1MB */ |
121 | mp->size = (mem & 0xffff) * 1024; |
122 | mp->type = BIOS_MAP_FREE0x01; |
123 | |
124 | return ++mp; |
125 | } |
126 | |
127 | /* |
128 | * BIOS int 0x12 Get Conventional Memory |
129 | * |
130 | * Only used if int 15, AX=E820 does not work. |
131 | */ |
132 | static __inline bios_memmap_t * |
133 | bios_int12(bios_memmap_t *mp) |
134 | { |
135 | int mem; |
136 | #ifdef DEBUG |
137 | printf("0x12 "); |
138 | #endif |
139 | __asm volatile(DOINT(0x12)"int $0x20+(" "0x12" ")" : "=a" (mem) :: "%ecx", "%edx", "cc"); |
140 | |
141 | /* Fill out a bios_memmap_t */ |
142 | mp->addr = 0; |
143 | mp->size = (mem & 0xffff) * 1024; |
144 | mp->type = BIOS_MAP_FREE0x01; |
145 | |
146 | return ++mp; |
147 | } |
148 | |
149 | /* |
150 | * addrprobe(kloc): Probe memory at address kloc * 1024. |
151 | * |
152 | * This is a hack, but it seems to work ok. Maybe this is |
153 | * the *real* way that you are supposed to do probing??? |
154 | * |
155 | * Modify the original a bit. We write everything first, and |
156 | * then test for the values. This should croak on machines that |
157 | * return values just written on non-existent memory... |
158 | * |
159 | * BTW: These machines are pretty broken IMHO. |
160 | * |
161 | * XXX - Does not detect aliased memory. |
162 | */ |
163 | const u_int addrprobe_pat[] = { |
164 | 0x00000000, 0xFFFFFFFF, |
165 | 0x01010101, 0x10101010, |
166 | 0x55555555, 0xCCCCCCCC |
167 | }; |
168 | static int |
169 | addrprobe(u_int kloc) |
170 | { |
171 | volatile u_int *loc; |
172 | register u_int i, ret = 0; |
173 | u_int save[nitems(addrprobe_pat)(sizeof((addrprobe_pat)) / sizeof((addrprobe_pat)[0]))]; |
174 | |
175 | /* Get location */ |
176 | loc = (int *)(intptr_t)(kloc * 1024); |
177 | |
178 | save[0] = *loc; |
179 | /* Probe address */ |
180 | for (i = 0; i < nitems(addrprobe_pat)(sizeof((addrprobe_pat)) / sizeof((addrprobe_pat)[0])); i++) { |
181 | *loc = addrprobe_pat[i]; |
182 | if (*loc != addrprobe_pat[i]) |
183 | ret++; |
184 | } |
185 | *loc = save[0]; |
186 | |
187 | if (!ret) { |
188 | /* Write address */ |
189 | for (i = 0; i < nitems(addrprobe_pat)(sizeof((addrprobe_pat)) / sizeof((addrprobe_pat)[0])); i++) { |
190 | save[i] = loc[i]; |
191 | loc[i] = addrprobe_pat[i]; |
192 | } |
193 | |
194 | /* Read address */ |
195 | for (i = 0; i < nitems(addrprobe_pat)(sizeof((addrprobe_pat)) / sizeof((addrprobe_pat)[0])); i++) { |
196 | if (loc[i] != addrprobe_pat[i]) |
197 | ret++; |
198 | loc[i] = save[i]; |
199 | } |
200 | } |
201 | |
202 | return ret; |
203 | } |
204 | |
205 | /* |
206 | * Probe for all extended memory. |
207 | * |
208 | * This is only used as a last resort. If we resort to this |
209 | * routine, we are getting pretty desperate. Hopefully nobody |
210 | * has to rely on this after all the work above. |
211 | * |
212 | * XXX - Does not detect aliased memory. |
213 | * XXX - Could be destructive, as it does write. |
214 | */ |
215 | static __inline bios_memmap_t * |
216 | badprobe(bios_memmap_t *mp) |
217 | { |
218 | u_int64_t ram; |
219 | #ifdef DEBUG |
220 | printf("scan "); |
221 | #endif |
222 | /* |
223 | * probe extended memory |
224 | * |
225 | * There is no need to do this in assembly language. This is |
226 | * much easier to debug in C anyways. |
227 | */ |
228 | for (ram = 1024; ram < 512 * 1024; ram += 4) |
229 | if (addrprobe(ram)) |
230 | break; |
231 | |
232 | mp->addr = 1024 * 1024; |
233 | mp->size = (ram - 1024) * 1024; |
234 | mp->type = BIOS_MAP_FREE0x01; |
235 | |
236 | return ++mp; |
237 | } |
238 | |
239 | void |
240 | memprobe(void) |
241 | { |
242 | bios_memmap_t *pm = bios_memmap, *im; |
Value stored to 'pm' during its initialization is never read | |
243 | |
244 | #ifdef DEBUG |
245 | printf(" mem("); |
246 | #else |
247 | printf(" mem["); |
248 | #endif |
249 | |
250 | if ((pm = bios_E820(bios_memmap)) == NULL((void *)0)) { |
251 | im = bios_int12(bios_memmap); |
252 | pm = bios_8800(im); |
253 | if (pm == NULL((void *)0)) |
254 | pm = badprobe(im); |
255 | if (pm == NULL((void *)0)) { |
256 | printf(" No Extended memory detected."); |
257 | pm = im; |
258 | } |
259 | } |
260 | pm->type = BIOS_MAP_END0x00; |
261 | |
262 | /* XXX - gotta peephole optimize the list */ |
263 | |
264 | #ifdef DEBUG |
265 | printf(")["); |
266 | #endif |
267 | |
268 | /* XXX - Compatibility, remove later (smpprobe() relies on it) */ |
269 | extmem = cnvmem = 0; |
270 | for (im = bios_memmap; im->type != BIOS_MAP_END0x00; im++) { |
271 | /* Count only "good" memory chunks 12K and up in size */ |
272 | if ((im->type == BIOS_MAP_FREE0x01) && (im->size >= 12 * 1024)) { |
273 | if (im->size > 1024 * 1024) |
274 | printf("%uM ", (u_int)(im->size / |
275 | (1024 * 1024))); |
276 | else |
277 | printf("%uK ", (u_int)im->size / 1024); |
278 | |
279 | /* |
280 | * Compute compatibility values: |
281 | * cnvmem -- is the upper boundary of conventional |
282 | * memory (below IOM_BEGIN (=640k)) |
283 | * extmem -- is the size of the contiguous extended |
284 | * memory segment starting at 1M |
285 | * |
286 | * We ignore "good" memory in the 640K-1M hole. |
287 | * We drop "machine {cnvmem,extmem}" commands. |
288 | */ |
289 | if (im->addr < IOM_BEGIN0x0a0000) |
290 | cnvmem = max(cnvmem,(((cnvmem)>(im->addr + im->size))? (cnvmem) : (im-> addr + im->size)) |
291 | im->addr + im->size)(((cnvmem)>(im->addr + im->size))? (cnvmem) : (im-> addr + im->size)) / 1024; |
292 | if (im->addr >= IOM_END0x100000 && |
293 | (im->addr / 1024) == (extmem + 1024)) |
294 | extmem += im->size / 1024; |
295 | } |
296 | } |
297 | |
298 | /* |
299 | * Adjust extmem to be no more than 4G (which it usually is not |
300 | * anyways). In order for an x86 type machine (amd64/etc) to use |
301 | * more than 4GB of memory, it will need to grok and use the bios |
302 | * memory map we pass it. Note that above we only count CONTIGUOUS |
303 | * memory from the 1MB boundary on for extmem (think I/O holes). |
304 | * |
305 | * extmem is in KB, and we have 4GB - 1MB (base/io hole) worth of it. |
306 | */ |
307 | if (extmem > 4 * 1024 * 1024 - 1024) |
308 | extmem = 4 * 1024 * 1024 - 1024; |
309 | |
310 | /* Check if gate A20 is on */ |
311 | printf("a20=o%s] ", checkA20()? "n" : "ff!"); |
312 | } |
313 | |
314 | void |
315 | dump_biosmem(bios_memmap_t *tm) |
316 | { |
317 | register bios_memmap_t *p; |
318 | register u_int total = 0; |
319 | |
320 | if (tm == NULL((void *)0)) |
321 | tm = bios_memmap; |
322 | |
323 | for (p = tm; p->type != BIOS_MAP_END0x00; p++) { |
324 | printf("Region %ld: type %u at 0x%llx for %uKB\n", |
325 | (long)(p - tm), p->type, p->addr, |
326 | (u_int)(p->size / 1024)); |
327 | |
328 | if (p->type == BIOS_MAP_FREE0x01) |
329 | total += p->size / 1024; |
330 | } |
331 | |
332 | printf("Low ram: %dKB High ram: %dKB\n", cnvmem, extmem); |
333 | printf("Total free memory: %uKB\n", total); |
334 | } |
335 | |
336 | int |
337 | mem_limit(long long ml) |
338 | { |
339 | register bios_memmap_t *p; |
340 | |
341 | for (p = bios_memmap; p->type != BIOS_MAP_END0x00; p++) { |
342 | register int64_t sp = p->addr, ep = p->addr + p->size; |
343 | |
344 | if (p->type != BIOS_MAP_FREE0x01) |
345 | continue; |
346 | |
347 | /* Wholly above limit, nuke it */ |
348 | if ((sp >= ml) && (ep >= ml)) { |
349 | bcopy (p + 1, p, (char *)bios_memmap +((void)memmove((p),(p + 1),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)p))) |
350 | sizeof(bios_memmap) - (char *)p)((void)memmove((p),(p + 1),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)p))); |
351 | } else if ((sp < ml) && (ep >= ml)) { |
352 | p->size -= (ep - ml); |
353 | } |
354 | } |
355 | return 0; |
356 | } |
357 | |
358 | int |
359 | mem_delete(long long sa, long long ea) |
360 | { |
361 | register bios_memmap_t *p; |
362 | |
363 | for (p = bios_memmap; p->type != BIOS_MAP_END0x00; p++) { |
364 | if (p->type == BIOS_MAP_FREE0x01) { |
365 | register int64_t sp = p->addr, ep = p->addr + p->size; |
366 | |
367 | /* can we eat it as a whole? */ |
368 | if ((sa - sp) <= PAGE_SIZE(1 << 12) && (ep - ea) <= PAGE_SIZE(1 << 12)) { |
369 | bcopy(p + 1, p, (char *)bios_memmap +((void)memmove((p),(p + 1),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)p))) |
370 | sizeof(bios_memmap) - (char *)p)((void)memmove((p),(p + 1),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)p))); |
371 | break; |
372 | /* eat head or legs */ |
373 | } else if (sa <= sp && sp < ea) { |
374 | p->addr = ea; |
375 | p->size = ep - ea; |
376 | break; |
377 | } else if (sa < ep && ep <= ea) { |
378 | p->size = sa - sp; |
379 | break; |
380 | } else if (sp < sa && ea < ep) { |
381 | /* bite in half */ |
382 | bcopy(p, p + 1, (char *)bios_memmap +((void)memmove((p + 1),(p),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)p - sizeof(bios_memmap[0])))) |
383 | sizeof(bios_memmap) - (char *)p -((void)memmove((p + 1),(p),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)p - sizeof(bios_memmap[0])))) |
384 | sizeof(bios_memmap[0]))((void)memmove((p + 1),(p),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)p - sizeof(bios_memmap[0])))); |
385 | p[1].addr = ea; |
386 | p[1].size = ep - ea; |
387 | p->size = sa - sp; |
388 | break; |
389 | } |
390 | } |
391 | } |
392 | return 0; |
393 | } |
394 | |
395 | int |
396 | mem_add(long long sa, long long ea) |
397 | { |
398 | register bios_memmap_t *p; |
399 | |
400 | for (p = bios_memmap; p->type != BIOS_MAP_END0x00; p++) { |
401 | if (p->type == BIOS_MAP_FREE0x01) { |
402 | register int64_t sp = p->addr, ep = p->addr + p->size; |
403 | |
404 | /* is it already there? */ |
405 | if (sp <= sa && ea <= ep) { |
406 | break; |
407 | /* join head or legs */ |
408 | } else if (sa < sp && sp <= ea) { |
409 | p->addr = sa; |
410 | p->size = ep - sa; |
411 | break; |
412 | } else if (sa <= ep && ep < ea) { |
413 | p->size = ea - sp; |
414 | break; |
415 | } else if (ea < sp) { |
416 | /* insert before */ |
417 | bcopy(p, p + 1, (char *)bios_memmap +((void)memmove((p + 1),(p),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)(p - 1)))) |
418 | sizeof(bios_memmap) - (char *)(p - 1))((void)memmove((p + 1),(p),((char *)bios_memmap + sizeof(bios_memmap ) - (char *)(p - 1)))); |
419 | p->addr = sa; |
420 | p->size = ea - sa; |
421 | break; |
422 | } |
423 | } |
424 | } |
425 | |
426 | /* meaning add new item at the end of the list */ |
427 | if (p->type == BIOS_MAP_END0x00) { |
428 | p[1] = p[0]; |
429 | p->type = BIOS_MAP_FREE0x01; |
430 | p->addr = sa; |
431 | p->size = ea - sa; |
432 | } |
433 | |
434 | return 0; |
435 | } |
436 | |
437 | void |
438 | mem_pass(void) |
439 | { |
440 | bios_memmap_t *p; |
441 | |
442 | for (p = bios_memmap; p->type != BIOS_MAP_END0x00; p++) |
443 | ; |
444 | addbootarg(BOOTARG_MEMMAP0, (p - bios_memmap + 1) * sizeof *bios_memmap, |
445 | bios_memmap); |
446 | } |