1 /*-
2 * Copyright (c) 2013 The FreeBSD Foundation
3 *
4 * This software was developed by Benno Rice under sponsorship from
5 * the FreeBSD Foundation.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/param.h>
29
30 #include <stand.h>
31 #include <bootstrap.h>
32
33 #include <efi.h>
34 #include <efilib.h>
35
36 #include "loader_efi.h"
37
38 #define M(x) ((x) * 1024 * 1024)
39 #define G(x) (1ULL * (x) * 1024 * 1024 * 1024)
40
41 #if defined(__amd64__)
42 #include <machine/cpufunc.h>
43 #include <machine/specialreg.h>
44 #include <machine/vmparam.h>
45
46 /*
47 * The code is excerpted from sys/x86/x86/identcpu.c: identify_cpu(),
48 * identify_hypervisor(), and dev/hyperv/vmbus/hyperv.c: hyperv_identify().
49 */
50 #define CPUID_LEAF_HV_MAXLEAF 0x40000000
51 #define CPUID_LEAF_HV_INTERFACE 0x40000001
52 #define CPUID_LEAF_HV_FEATURES 0x40000003
53 #define CPUID_LEAF_HV_LIMITS 0x40000005
54 #define CPUID_HV_IFACE_HYPERV 0x31237648 /* HV#1 */
55 #define CPUID_HV_MSR_TIME_REFCNT 0x0002 /* MSR_HV_TIME_REF_COUNT */
56 #define CPUID_HV_MSR_HYPERCALL 0x0020
57
58 static int
running_on_hyperv(void)59 running_on_hyperv(void)
60 {
61 char hv_vendor[16];
62 uint32_t regs[4];
63
64 do_cpuid(1, regs);
65 if ((regs[2] & CPUID2_HV) == 0)
66 return (0);
67
68 do_cpuid(CPUID_LEAF_HV_MAXLEAF, regs);
69 if (regs[0] < CPUID_LEAF_HV_LIMITS)
70 return (0);
71
72 ((uint32_t *)&hv_vendor)[0] = regs[1];
73 ((uint32_t *)&hv_vendor)[1] = regs[2];
74 ((uint32_t *)&hv_vendor)[2] = regs[3];
75 hv_vendor[12] = '\0';
76 if (strcmp(hv_vendor, "Microsoft Hv") != 0)
77 return (0);
78
79 do_cpuid(CPUID_LEAF_HV_INTERFACE, regs);
80 if (regs[0] != CPUID_HV_IFACE_HYPERV)
81 return (0);
82
83 do_cpuid(CPUID_LEAF_HV_FEATURES, regs);
84 if ((regs[0] & CPUID_HV_MSR_HYPERCALL) == 0)
85 return (0);
86 if ((regs[0] & CPUID_HV_MSR_TIME_REFCNT) == 0)
87 return (0);
88
89 return (1);
90 }
91
92 static void
efi_verify_staging_size(unsigned long * nr_pages)93 efi_verify_staging_size(unsigned long *nr_pages)
94 {
95 UINTN sz;
96 EFI_MEMORY_DESCRIPTOR *map = NULL, *p;
97 EFI_PHYSICAL_ADDRESS start, end;
98 UINTN key, dsz;
99 UINT32 dver;
100 EFI_STATUS status;
101 int i, ndesc;
102 unsigned long available_pages = 0;
103
104 sz = 0;
105
106 for (;;) {
107 status = BS->GetMemoryMap(&sz, map, &key, &dsz, &dver);
108 if (!EFI_ERROR(status))
109 break;
110
111 if (status != EFI_BUFFER_TOO_SMALL) {
112 printf("Can't read memory map: %lu\n",
113 EFI_ERROR_CODE(status));
114 goto out;
115 }
116
117 free(map);
118
119 /* Allocate 10 descriptors more than the size reported,
120 * to allow for any fragmentation caused by calling
121 * malloc */
122 map = malloc(sz + (10 * dsz));
123 if (map == NULL) {
124 printf("Unable to allocate memory\n");
125 goto out;
126 }
127 }
128
129 ndesc = sz / dsz;
130 for (i = 0, p = map; i < ndesc;
131 i++, p = NextMemoryDescriptor(p, dsz)) {
132 start = p->PhysicalStart;
133 end = start + p->NumberOfPages * EFI_PAGE_SIZE;
134
135 if (KERNLOAD < start || KERNLOAD >= end)
136 continue;
137
138 available_pages = p->NumberOfPages -
139 ((KERNLOAD - start) >> EFI_PAGE_SHIFT);
140 break;
141 }
142
143 if (available_pages == 0) {
144 printf("Can't find valid memory map for staging area!\n");
145 goto out;
146 }
147
148 i++;
149 p = NextMemoryDescriptor(p, dsz);
150
151 for ( ; i < ndesc;
152 i++, p = NextMemoryDescriptor(p, dsz)) {
153 if (p->Type != EfiConventionalMemory &&
154 p->Type != EfiLoaderData)
155 break;
156
157 if (p->PhysicalStart != end)
158 break;
159
160 end = p->PhysicalStart + p->NumberOfPages * EFI_PAGE_SIZE;
161
162 available_pages += p->NumberOfPages;
163 }
164
165 if (*nr_pages > available_pages) {
166 printf("Staging area's size is reduced: %ld -> %ld!\n",
167 *nr_pages, available_pages);
168 *nr_pages = available_pages;
169 }
170 out:
171 free(map);
172 }
173 #endif /* __amd64__ */
174
175 #if defined(__arm__)
176 #define DEFAULT_EFI_STAGING_SIZE 32
177 #else
178 #define DEFAULT_EFI_STAGING_SIZE 64
179 #endif
180 #ifndef EFI_STAGING_SIZE
181 #define EFI_STAGING_SIZE DEFAULT_EFI_STAGING_SIZE
182 #endif
183
184 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \
185 defined(__riscv)
186 #define EFI_STAGING_2M_ALIGN 1
187 #else
188 #define EFI_STAGING_2M_ALIGN 0
189 #endif
190
191 #if defined(__amd64__)
192 #define EFI_STAGING_SLOP M(8)
193 #else
194 #define EFI_STAGING_SLOP 0
195 #endif
196
197 static u_long staging_slop = EFI_STAGING_SLOP;
198
199 EFI_PHYSICAL_ADDRESS staging, staging_end, staging_base;
200 bool stage_offset_set = false;
201 ssize_t stage_offset;
202
203 static void
efi_copy_free(void)204 efi_copy_free(void)
205 {
206 BS->FreePages(staging_base, (staging_end - staging_base) /
207 EFI_PAGE_SIZE);
208 stage_offset_set = false;
209 stage_offset = 0;
210 }
211
212 #ifdef __amd64__
213 int copy_staging = COPY_STAGING_AUTO;
214
215 static int
command_copy_staging(int argc,char * argv[])216 command_copy_staging(int argc, char *argv[])
217 {
218 static const char *const mode[3] = {
219 [COPY_STAGING_ENABLE] = "enable",
220 [COPY_STAGING_DISABLE] = "disable",
221 [COPY_STAGING_AUTO] = "auto",
222 };
223 int prev, res;
224
225 res = CMD_OK;
226 if (argc > 2) {
227 res = CMD_ERROR;
228 } else if (argc == 2) {
229 prev = copy_staging;
230 if (strcmp(argv[1], "enable") == 0)
231 copy_staging = COPY_STAGING_ENABLE;
232 else if (strcmp(argv[1], "disable") == 0)
233 copy_staging = COPY_STAGING_DISABLE;
234 else if (strcmp(argv[1], "auto") == 0)
235 copy_staging = COPY_STAGING_AUTO;
236 else {
237 printf("usage: copy_staging enable|disable|auto\n");
238 res = CMD_ERROR;
239 }
240 if (res == CMD_OK && prev != copy_staging) {
241 printf("changed copy_staging, unloading kernel\n");
242 unload();
243 efi_copy_free();
244 efi_copy_init();
245 }
246 } else {
247 printf("copy staging: %s\n", mode[copy_staging]);
248 }
249 return (res);
250 }
251 COMMAND_SET(copy_staging, "copy_staging", "copy staging", command_copy_staging);
252 #endif
253
254 static int
command_staging_slop(int argc,char * argv[])255 command_staging_slop(int argc, char *argv[])
256 {
257 char *endp;
258 u_long new, prev;
259 int res;
260
261 res = CMD_OK;
262 if (argc > 2) {
263 res = CMD_ERROR;
264 } else if (argc == 2) {
265 new = strtoul(argv[1], &endp, 0);
266 if (*endp != '\0') {
267 printf("invalid slop value\n");
268 res = CMD_ERROR;
269 }
270 if (res == CMD_OK && staging_slop != new) {
271 printf("changed slop, unloading kernel\n");
272 unload();
273 efi_copy_free();
274 efi_copy_init();
275 }
276 } else {
277 printf("staging slop %#lx\n", staging_slop);
278 }
279 return (res);
280 }
281 COMMAND_SET(staging_slop, "staging_slop", "set staging slop",
282 command_staging_slop);
283
284 #if defined(__amd64__)
285 /*
286 * The staging area must reside in the first 1GB or 4GB physical
287 * memory: see elf64_exec() in
288 * boot/efi/loader/arch/amd64/elf64_freebsd.c.
289 */
290 static EFI_PHYSICAL_ADDRESS
get_staging_max(void)291 get_staging_max(void)
292 {
293 EFI_PHYSICAL_ADDRESS res;
294
295 res = copy_staging == COPY_STAGING_ENABLE ? G(1) : G(4);
296 return (res);
297 }
298 #define EFI_ALLOC_METHOD AllocateMaxAddress
299 #else
300 #define EFI_ALLOC_METHOD AllocateAnyPages
301 #endif
302
303 int
efi_copy_init(void)304 efi_copy_init(void)
305 {
306 EFI_STATUS status;
307 unsigned long nr_pages;
308 vm_offset_t ess;
309
310 ess = EFI_STAGING_SIZE;
311 if (ess < DEFAULT_EFI_STAGING_SIZE)
312 ess = DEFAULT_EFI_STAGING_SIZE;
313 nr_pages = EFI_SIZE_TO_PAGES(M(1) * ess);
314
315 #if defined(__amd64__)
316 /*
317 * We'll decrease nr_pages, if it's too big. Currently we only
318 * apply this to FreeBSD VM running on Hyper-V. Why? Please see
319 * https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=211746#c28
320 */
321 if (running_on_hyperv())
322 efi_verify_staging_size(&nr_pages);
323
324 staging = get_staging_max();
325 #endif
326 status = BS->AllocatePages(EFI_ALLOC_METHOD, EfiLoaderCode,
327 nr_pages, &staging);
328 if (EFI_ERROR(status)) {
329 printf("failed to allocate staging area: %lu\n",
330 EFI_ERROR_CODE(status));
331 return (status);
332 }
333 staging_base = staging;
334 staging_end = staging + nr_pages * EFI_PAGE_SIZE;
335
336 #if EFI_STAGING_2M_ALIGN
337 /*
338 * Round the kernel load address to a 2MiB value. This is needed
339 * because the kernel builds a page table based on where it has
340 * been loaded in physical address space. As the kernel will use
341 * either a 1MiB or 2MiB page for this we need to make sure it
342 * is correctly aligned for both cases.
343 */
344 staging = roundup2(staging, M(2));
345 #endif
346
347 return (0);
348 }
349
350 static bool
efi_check_space(vm_offset_t end)351 efi_check_space(vm_offset_t end)
352 {
353 EFI_PHYSICAL_ADDRESS addr, new_base, new_staging;
354 EFI_STATUS status;
355 unsigned long nr_pages;
356
357 end = roundup2(end, EFI_PAGE_SIZE);
358
359 /* There is already enough space */
360 if (end + staging_slop <= staging_end)
361 return (true);
362
363 if (!boot_services_active) {
364 if (end <= staging_end)
365 return (true);
366 panic("efi_check_space: cannot expand staging area "
367 "after boot services were exited\n");
368 }
369
370 /*
371 * Add slop at the end:
372 * 1. amd64 kernel expects to do some very early allocations
373 * by carving out memory after kernend. Slop guarantees
374 * that it does not ovewrite anything useful.
375 * 2. It seems that initial calculation of the staging size
376 * could be somewhat smaller than actually copying in after
377 * boot services are exited. Slop avoids calling
378 * BS->AllocatePages() when it cannot work.
379 */
380 end += staging_slop;
381
382 nr_pages = EFI_SIZE_TO_PAGES(end - staging_end);
383 #if defined(__amd64__)
384 /*
385 * amd64 needs all memory to be allocated under the 1G or 4G boundary.
386 */
387 if (end > get_staging_max())
388 goto before_staging;
389 #endif
390
391 /* Try to allocate more space after the previous allocation */
392 addr = staging_end;
393 status = BS->AllocatePages(AllocateAddress, EfiLoaderCode, nr_pages,
394 &addr);
395 if (!EFI_ERROR(status)) {
396 staging_end = staging_end + nr_pages * EFI_PAGE_SIZE;
397 return (true);
398 }
399
400 before_staging:
401 /* Try allocating space before the previous allocation */
402 if (staging < nr_pages * EFI_PAGE_SIZE)
403 goto expand;
404 addr = staging - nr_pages * EFI_PAGE_SIZE;
405 #if EFI_STAGING_2M_ALIGN
406 /* See efi_copy_init for why this is needed */
407 addr = rounddown2(addr, M(2));
408 #endif
409 nr_pages = EFI_SIZE_TO_PAGES(staging_base - addr);
410 status = BS->AllocatePages(AllocateAddress, EfiLoaderCode, nr_pages,
411 &addr);
412 if (!EFI_ERROR(status)) {
413 /*
414 * Move the old allocation and update the state so
415 * translation still works.
416 */
417 staging_base = addr;
418 memmove((void *)(uintptr_t)staging_base,
419 (void *)(uintptr_t)staging, staging_end - staging);
420 stage_offset -= staging - staging_base;
421 staging = staging_base;
422 return (true);
423 }
424
425 expand:
426 nr_pages = EFI_SIZE_TO_PAGES(end - (vm_offset_t)staging);
427 #if EFI_STAGING_2M_ALIGN
428 nr_pages += M(2) / EFI_PAGE_SIZE;
429 #endif
430 #if defined(__amd64__)
431 new_base = get_staging_max();
432 #endif
433 status = BS->AllocatePages(EFI_ALLOC_METHOD, EfiLoaderCode,
434 nr_pages, &new_base);
435 if (!EFI_ERROR(status)) {
436 #if EFI_STAGING_2M_ALIGN
437 new_staging = roundup2(new_base, M(2));
438 #else
439 new_staging = new_base;
440 #endif
441 /*
442 * Move the old allocation and update the state so
443 * translation still works.
444 */
445 memcpy((void *)(uintptr_t)new_staging,
446 (void *)(uintptr_t)staging, staging_end - staging);
447 BS->FreePages(staging_base, (staging_end - staging_base) /
448 EFI_PAGE_SIZE);
449 stage_offset -= staging - new_staging;
450 staging = new_staging;
451 staging_end = new_base + nr_pages * EFI_PAGE_SIZE;
452 staging_base = new_base;
453 return (true);
454 }
455
456 printf("efi_check_space: Unable to expand staging area\n");
457 return (false);
458 }
459
460 void *
efi_translate(vm_offset_t ptr)461 efi_translate(vm_offset_t ptr)
462 {
463
464 return ((void *)(ptr + stage_offset));
465 }
466
467 ssize_t
efi_copyin(const void * src,vm_offset_t dest,const size_t len)468 efi_copyin(const void *src, vm_offset_t dest, const size_t len)
469 {
470
471 if (!stage_offset_set) {
472 stage_offset = (vm_offset_t)staging - dest;
473 stage_offset_set = true;
474 }
475
476 /* XXX: Callers do not check for failure. */
477 if (!efi_check_space(dest + stage_offset + len)) {
478 errno = ENOMEM;
479 return (-1);
480 }
481 bcopy(src, (void *)(dest + stage_offset), len);
482 return (len);
483 }
484
485 ssize_t
efi_copyout(const vm_offset_t src,void * dest,const size_t len)486 efi_copyout(const vm_offset_t src, void *dest, const size_t len)
487 {
488
489 /* XXX: Callers do not check for failure. */
490 if (src + stage_offset + len > staging_end) {
491 errno = ENOMEM;
492 return (-1);
493 }
494 bcopy((void *)(src + stage_offset), dest, len);
495 return (len);
496 }
497
498 ssize_t
efi_readin(readin_handle_t fd,vm_offset_t dest,const size_t len)499 efi_readin(readin_handle_t fd, vm_offset_t dest, const size_t len)
500 {
501
502 if (!stage_offset_set) {
503 stage_offset = (vm_offset_t)staging - dest;
504 stage_offset_set = true;
505 }
506
507 if (!efi_check_space(dest + stage_offset + len)) {
508 errno = ENOMEM;
509 return (-1);
510 }
511 return (VECTX_READ(fd, (void *)(dest + stage_offset), len));
512 }
513
514 void
efi_copy_finish(void)515 efi_copy_finish(void)
516 {
517 uint64_t *src, *dst, *last;
518
519 src = (uint64_t *)(uintptr_t)staging;
520 dst = (uint64_t *)(uintptr_t)(staging - stage_offset);
521 last = (uint64_t *)(uintptr_t)staging_end;
522
523 while (src < last)
524 *dst++ = *src++;
525 }
526
527 void
efi_copy_finish_nop(void)528 efi_copy_finish_nop(void)
529 {
530 }
531