1 /*-
2 * Copyright (c) 2013 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Benno Rice under sponsorship from
6 * the FreeBSD Foundation.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33
34 #include <stand.h>
35 #include <bootstrap.h>
36
37 #include <efi.h>
38 #include <efilib.h>
39
40 #include "loader_efi.h"
41
42 #if defined(__i386__) || defined(__amd64__)
43 #include <machine/cpufunc.h>
44 #include <machine/specialreg.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 #define KERNEL_PHYSICAL_BASE (2*1024*1024)
93
94 static void
efi_verify_staging_size(unsigned long * nr_pages)95 efi_verify_staging_size(unsigned long *nr_pages)
96 {
97 UINTN sz;
98 EFI_MEMORY_DESCRIPTOR *map = NULL, *p;
99 EFI_PHYSICAL_ADDRESS start, end;
100 UINTN key, dsz;
101 UINT32 dver;
102 EFI_STATUS status;
103 int i, ndesc;
104 unsigned long available_pages = 0;
105
106 sz = 0;
107
108 for (;;) {
109 status = BS->GetMemoryMap(&sz, map, &key, &dsz, &dver);
110 if (!EFI_ERROR(status))
111 break;
112
113 if (status != EFI_BUFFER_TOO_SMALL) {
114 printf("Can't read memory map: %lu\n",
115 EFI_ERROR_CODE(status));
116 goto out;
117 }
118
119 free(map);
120
121 /* Allocate 10 descriptors more than the size reported,
122 * to allow for any fragmentation caused by calling
123 * malloc */
124 map = malloc(sz + (10 * dsz));
125 if (map == NULL) {
126 printf("Unable to allocate memory\n");
127 goto out;
128 }
129 }
130
131 ndesc = sz / dsz;
132 for (i = 0, p = map; i < ndesc;
133 i++, p = NextMemoryDescriptor(p, dsz)) {
134 start = p->PhysicalStart;
135 end = start + p->NumberOfPages * EFI_PAGE_SIZE;
136
137 if (KERNEL_PHYSICAL_BASE < start ||
138 KERNEL_PHYSICAL_BASE >= end)
139 continue;
140
141 available_pages = p->NumberOfPages -
142 ((KERNEL_PHYSICAL_BASE - start) >> EFI_PAGE_SHIFT);
143 break;
144 }
145
146 if (available_pages == 0) {
147 printf("Can't find valid memory map for staging area!\n");
148 goto out;
149 }
150
151 i++;
152 p = NextMemoryDescriptor(p, dsz);
153
154 for ( ; i < ndesc;
155 i++, p = NextMemoryDescriptor(p, dsz)) {
156 if (p->Type != EfiConventionalMemory &&
157 p->Type != EfiLoaderData)
158 break;
159
160 if (p->PhysicalStart != end)
161 break;
162
163 end = p->PhysicalStart + p->NumberOfPages * EFI_PAGE_SIZE;
164
165 available_pages += p->NumberOfPages;
166 }
167
168 if (*nr_pages > available_pages) {
169 printf("Staging area's size is reduced: %ld -> %ld!\n",
170 *nr_pages, available_pages);
171 *nr_pages = available_pages;
172 }
173 out:
174 free(map);
175 }
176 #endif /* __i386__ || __amd64__ */
177
178 #ifndef EFI_STAGING_SIZE
179 #define EFI_STAGING_SIZE 64
180 #endif
181
182 EFI_PHYSICAL_ADDRESS staging, staging_end;
183 int stage_offset_set = 0;
184 ssize_t stage_offset;
185
186 int
efi_copy_init(void)187 efi_copy_init(void)
188 {
189 EFI_STATUS status;
190
191 unsigned long nr_pages;
192
193 nr_pages = EFI_SIZE_TO_PAGES((EFI_STAGING_SIZE) * 1024 * 1024);
194
195 #if defined(__i386__) || defined(__amd64__)
196 /*
197 * We'll decrease nr_pages, if it's too big. Currently we only
198 * apply this to FreeBSD VM running on Hyper-V. Why? Please see
199 * https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=211746#c28
200 */
201 if (running_on_hyperv())
202 efi_verify_staging_size(&nr_pages);
203
204 /*
205 * The staging area must reside in the the first 1GB physical
206 * memory: see elf64_exec() in
207 * boot/efi/loader/arch/amd64/elf64_freebsd.c.
208 */
209 staging = 1024*1024*1024;
210 status = BS->AllocatePages(AllocateMaxAddress, EfiLoaderData,
211 nr_pages, &staging);
212 #else
213 status = BS->AllocatePages(AllocateAnyPages, EfiLoaderData,
214 nr_pages, &staging);
215 #endif
216 if (EFI_ERROR(status)) {
217 printf("failed to allocate staging area: %lu\n",
218 EFI_ERROR_CODE(status));
219 return (status);
220 }
221 staging_end = staging + nr_pages * EFI_PAGE_SIZE;
222
223 #if defined(__aarch64__) || defined(__arm__)
224 /*
225 * Round the kernel load address to a 2MiB value. This is needed
226 * because the kernel builds a page table based on where it has
227 * been loaded in physical address space. As the kernel will use
228 * either a 1MiB or 2MiB page for this we need to make sure it
229 * is correctly aligned for both cases.
230 */
231 staging = roundup2(staging, 2 * 1024 * 1024);
232 #endif
233
234 return (0);
235 }
236
237 void *
efi_translate(vm_offset_t ptr)238 efi_translate(vm_offset_t ptr)
239 {
240
241 return ((void *)(ptr + stage_offset));
242 }
243
244 ssize_t
efi_copyin(const void * src,vm_offset_t dest,const size_t len)245 efi_copyin(const void *src, vm_offset_t dest, const size_t len)
246 {
247
248 if (!stage_offset_set) {
249 stage_offset = (vm_offset_t)staging - dest;
250 stage_offset_set = 1;
251 }
252
253 /* XXX: Callers do not check for failure. */
254 if (dest + stage_offset + len > staging_end) {
255 errno = ENOMEM;
256 return (-1);
257 }
258 bcopy(src, (void *)(dest + stage_offset), len);
259 return (len);
260 }
261
262 ssize_t
efi_copyout(const vm_offset_t src,void * dest,const size_t len)263 efi_copyout(const vm_offset_t src, void *dest, const size_t len)
264 {
265
266 /* XXX: Callers do not check for failure. */
267 if (src + stage_offset + len > staging_end) {
268 errno = ENOMEM;
269 return (-1);
270 }
271 bcopy((void *)(src + stage_offset), dest, len);
272 return (len);
273 }
274
275
276 ssize_t
efi_readin(const int fd,vm_offset_t dest,const size_t len)277 efi_readin(const int fd, vm_offset_t dest, const size_t len)
278 {
279
280 if (dest + stage_offset + len > staging_end) {
281 errno = ENOMEM;
282 return (-1);
283 }
284 return (read(fd, (void *)(dest + stage_offset), len));
285 }
286
287 void
efi_copy_finish(void)288 efi_copy_finish(void)
289 {
290 uint64_t *src, *dst, *last;
291
292 src = (uint64_t *)(uintptr_t)staging;
293 dst = (uint64_t *)(uintptr_t)(staging - stage_offset);
294 last = (uint64_t *)(uintptr_t)staging_end;
295
296 while (src < last)
297 *dst++ = *src++;
298 }
299