1 /* $OpenBSD: memprobe.c,v 1.58 2024/11/18 02:32:22 mlarkin 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 #ifndef EFIBOOT 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) "; 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_RES; 89 mp++; 90 } while (off); 91 92 if (!gotcha) 93 return NULL; 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=E820 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) "; setc %b0" 112 : "=c" (rc), "=a" (mem) : "a" (0x8800)); 113 114 if (rc & 0xff) 115 return NULL; 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_FREE; 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) : "=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_FREE; 145 146 return ++mp; 147 } 148 149 150 /* 151 * addrprobe(kloc): Probe memory at address kloc * 1024. 152 * 153 * This is a hack, but it seems to work ok. Maybe this is 154 * the *real* way that you are supposed to do probing??? 155 * 156 * Modify the original a bit. We write everything first, and 157 * then test for the values. This should croak on machines that 158 * return values just written on non-existent memory... 159 * 160 * BTW: These machines are pretty broken IMHO. 161 * 162 * XXX - Does not detect aliased memory. 163 */ 164 const u_int addrprobe_pat[] = { 165 0x00000000, 0xFFFFFFFF, 166 0x01010101, 0x10101010, 167 0x55555555, 0xCCCCCCCC 168 }; 169 static int 170 addrprobe(u_int kloc) 171 { 172 volatile u_int *loc; 173 register u_int i, ret = 0; 174 u_int save[nitems(addrprobe_pat)]; 175 176 /* Get location */ 177 loc = (int *)(intptr_t)(kloc * 1024); 178 179 save[0] = *loc; 180 /* Probe address */ 181 for (i = 0; i < nitems(addrprobe_pat); i++) { 182 *loc = addrprobe_pat[i]; 183 if (*loc != addrprobe_pat[i]) 184 ret++; 185 } 186 *loc = save[0]; 187 188 if (!ret) { 189 /* Write address */ 190 for (i = 0; i < nitems(addrprobe_pat); i++) { 191 save[i] = loc[i]; 192 loc[i] = addrprobe_pat[i]; 193 } 194 195 /* Read address */ 196 for (i = 0; i < nitems(addrprobe_pat); i++) { 197 if (loc[i] != addrprobe_pat[i]) 198 ret++; 199 loc[i] = save[i]; 200 } 201 } 202 203 return ret; 204 } 205 206 /* 207 * Probe for all extended memory. 208 * 209 * This is only used as a last resort. If we resort to this 210 * routine, we are getting pretty desperate. Hopefully nobody 211 * has to rely on this after all the work above. 212 * 213 * XXX - Does not detect aliased memory. 214 * XXX - Could be destructive, as it does write. 215 */ 216 static __inline bios_memmap_t * 217 badprobe(bios_memmap_t *mp) 218 { 219 u_int64_t ram; 220 #ifdef DEBUG 221 printf("scan "); 222 #endif 223 /* 224 * probe extended memory 225 * 226 * There is no need to do this in assembly language. This is 227 * much easier to debug in C anyways. 228 */ 229 for (ram = 1024; ram < 512 * 1024; ram += 4) 230 if (addrprobe(ram)) 231 break; 232 233 mp->addr = 1024 * 1024; 234 mp->size = (ram - 1024) * 1024; 235 mp->type = BIOS_MAP_FREE; 236 237 return ++mp; 238 } 239 240 bios_memmap_t bios_memmap[64]; /* This is easier */ 241 242 void 243 memprobe(void) 244 { 245 bios_memmap_t *pm = bios_memmap, *im; 246 247 #ifdef DEBUG 248 printf(" mem("); 249 #else 250 printf(" mem["); 251 #endif 252 253 if ((pm = bios_E820(bios_memmap)) == NULL) { 254 im = bios_int12(bios_memmap); 255 pm = bios_8800(im); 256 if (pm == NULL) 257 pm = badprobe(im); 258 if (pm == NULL) { 259 printf(" No Extended memory detected."); 260 pm = im; 261 } 262 } 263 pm->type = BIOS_MAP_END; 264 265 /* XXX - gotta peephole optimize the list */ 266 267 /* Remove APM needed RAM */ 268 apmfixmem(); 269 270 #ifdef DEBUG 271 printf(")["); 272 #endif 273 274 /* XXX - Compatibility, remove later (smpprobe() relies on it) */ 275 extmem = cnvmem = 0; 276 for (im = bios_memmap; im->type != BIOS_MAP_END; im++) { 277 /* Count only "good" memory chunks 12K and up in size */ 278 if ((im->type == BIOS_MAP_FREE) && (im->size >= 12 * 1024)) { 279 if (im->size > 1024 * 1024) 280 printf("%uM ", (u_int)(im->size / 281 (1024 * 1024))); 282 else 283 printf("%uK ", (u_int)im->size / 1024); 284 285 /* 286 * Compute compatibility values: 287 * cnvmem -- is the upper boundary of conventional 288 * memory (below IOM_BEGIN (=640k)) 289 * extmem -- is the size of the contiguous extended 290 * memory segment starting at 1M 291 * 292 * We ignore "good" memory in the 640K-1M hole. 293 * We drop "machine {cnvmem,extmem}" commands. 294 */ 295 if (im->addr < IOM_BEGIN) 296 cnvmem = max(cnvmem, 297 im->addr + im->size) / 1024; 298 if (im->addr >= IOM_END) 299 extmem += im->size / 1024; 300 } 301 } 302 303 /* Check if gate A20 is on */ 304 printf("a20=o%s] ", checkA20()? "n" : "ff!"); 305 } 306 #endif 307 308 void 309 dump_biosmem(bios_memmap_t *tm) 310 { 311 register bios_memmap_t *p; 312 register u_int total = 0; 313 314 if (tm == NULL) 315 tm = bios_memmap; 316 317 for (p = tm; p->type != BIOS_MAP_END; p++) { 318 printf("Region %ld: type %u at 0x%llx for %uKB\n", 319 (long)(p - tm), p->type, p->addr, 320 (u_int)(p->size / 1024)); 321 322 if (p->type == BIOS_MAP_FREE) 323 total += p->size / 1024; 324 } 325 326 printf("Low ram: %dKB High ram: %dKB\n", cnvmem, extmem); 327 printf("Total free memory: %uKB\n", total); 328 } 329 330 int 331 mem_limit(long long ml) 332 { 333 register bios_memmap_t *p; 334 335 for (p = bios_memmap; p->type != BIOS_MAP_END; p++) { 336 register int64_t sp = p->addr, ep = p->addr + p->size; 337 338 if (p->type != BIOS_MAP_FREE) 339 continue; 340 341 /* Wholly above limit, nuke it */ 342 if ((sp >= ml) && (ep >= ml)) { 343 bcopy (p + 1, p, (char *)bios_memmap + 344 sizeof(bios_memmap) - (char *)p); 345 } else if ((sp < ml) && (ep >= ml)) { 346 p->size -= (ep - ml); 347 } 348 } 349 return 0; 350 } 351 352 int 353 mem_delete(long long sa, long long ea) 354 { 355 register bios_memmap_t *p; 356 357 for (p = bios_memmap; p->type != BIOS_MAP_END; p++) { 358 if (p->type == BIOS_MAP_FREE) { 359 register int64_t sp = p->addr, ep = p->addr + p->size; 360 361 /* can we eat it as a whole? */ 362 if ((sa - sp) <= PAGE_SIZE && (ep - ea) <= PAGE_SIZE) { 363 bcopy(p + 1, p, (char *)bios_memmap + 364 sizeof(bios_memmap) - (char *)p); 365 break; 366 /* eat head or legs */ 367 } else if (sa <= sp && sp < ea) { 368 p->addr = ea; 369 p->size = ep - ea; 370 break; 371 } else if (sa < ep && ep <= ea) { 372 p->size = sa - sp; 373 break; 374 } else if (sp < sa && ea < ep) { 375 /* bite in half */ 376 bcopy(p, p + 1, (char *)bios_memmap + 377 sizeof(bios_memmap) - (char *)p - 378 sizeof(bios_memmap[0])); 379 p[1].addr = ea; 380 p[1].size = ep - ea; 381 p->size = sa - sp; 382 break; 383 } 384 } 385 } 386 return 0; 387 } 388 389 int 390 mem_add(long long sa, long long ea) 391 { 392 register bios_memmap_t *p; 393 394 for (p = bios_memmap; p->type != BIOS_MAP_END; p++) { 395 if (p->type == BIOS_MAP_FREE) { 396 register int64_t sp = p->addr, ep = p->addr + p->size; 397 398 /* is it already there? */ 399 if (sp <= sa && ea <= ep) { 400 break; 401 /* join head or legs */ 402 } else if (sa < sp && sp <= ea) { 403 p->addr = sa; 404 p->size = ep - sa; 405 break; 406 } else if (sa <= ep && ep < ea) { 407 p->size = ea - sp; 408 break; 409 } else if (ea < sp) { 410 /* insert before */ 411 bcopy(p, p + 1, (char *)bios_memmap + 412 sizeof(bios_memmap) - (char *)(p - 1)); 413 p->addr = sa; 414 p->size = ea - sa; 415 break; 416 } 417 } 418 } 419 420 /* meaning add new item at the end of the list */ 421 if (p->type == BIOS_MAP_END) { 422 p[1] = p[0]; 423 p->type = BIOS_MAP_FREE; 424 p->addr = sa; 425 p->size = ea - sa; 426 } 427 428 return 0; 429 } 430 431 void 432 mem_pass(void) 433 { 434 bios_memmap_t *p; 435 436 for (p = bios_memmap; p->type != BIOS_MAP_END; p++) 437 ; 438 addbootarg(BOOTARG_MEMMAP, (p - bios_memmap + 1) * sizeof *bios_memmap, 439 bios_memmap); 440 } 441