| 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 | } |