summaryrefslogtreecommitdiffstats
path: root/src/boot/efi/util.c
blob: 5678b50c3100f79deaae506f56d6146c2fc8ffd6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * Copyright (C) 2012-2013 Kay Sievers <kay@vrfy.org>
 * Copyright (C) 2012 Harald Hoyer <harald@redhat.com>
 */

#include <efi.h>
#include <efilib.h>

#include "util.h"

/*
 * Allocated random UUID, intended to be shared across tools that implement
 * the (ESP)\loader\entries\<vendor>-<revision>.conf convention and the
 * associated EFI variables.
 */
static const EFI_GUID loader_guid = { 0x4a67b082, 0x0a4c, 0x41cf, {0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f} };

#ifdef __x86_64__
UINT64 ticks_read(VOID) {
        UINT64 a, d;
        __asm__ volatile ("rdtsc" : "=a" (a), "=d" (d));
        return (d << 32) | a;
}
#else
UINT64 ticks_read(VOID) {
        UINT64 val;
        __asm__ volatile ("rdtsc" : "=A" (val));
        return val;
}
#endif

/* count TSC ticks during a millisecond delay */
UINT64 ticks_freq(VOID) {
        UINT64 ticks_start, ticks_end;

        ticks_start = ticks_read();
        uefi_call_wrapper(BS->Stall, 1, 1000);
        ticks_end = ticks_read();

        return (ticks_end - ticks_start) * 1000;
}

UINT64 time_usec(VOID) {
        UINT64 ticks;
        static UINT64 freq;

        ticks = ticks_read();
        if (ticks == 0)
                return 0;

        if (freq == 0) {
                freq = ticks_freq();
                if (freq == 0)
                        return 0;
        }

        return 1000 * 1000 * ticks / freq;
}

EFI_STATUS efivar_set_raw(const EFI_GUID *vendor, CHAR16 *name, CHAR8 *buf, UINTN size, BOOLEAN persistent) {
        UINT32 flags;

        flags = EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS;
        if (persistent)
                flags |= EFI_VARIABLE_NON_VOLATILE;

        return uefi_call_wrapper(RT->SetVariable, 5, name, (EFI_GUID *)vendor, flags, size, buf);
}

EFI_STATUS efivar_set(CHAR16 *name, CHAR16 *value, BOOLEAN persistent) {
        return efivar_set_raw(&loader_guid, name, (CHAR8 *)value, value ? (StrLen(value)+1) * sizeof(CHAR16) : 0, persistent);
}

EFI_STATUS efivar_set_int(CHAR16 *name, UINTN i, BOOLEAN persistent) {
        CHAR16 str[32];

        SPrint(str, 32, L"%d", i);
        return efivar_set(name, str, persistent);
}

EFI_STATUS efivar_get(CHAR16 *name, CHAR16 **value) {
        CHAR8 *buf;
        CHAR16 *val;
        UINTN size;
        EFI_STATUS err;

        err = efivar_get_raw(&loader_guid, name, &buf, &size);
        if (EFI_ERROR(err))
                return err;

        val = StrDuplicate((CHAR16 *)buf);
        if (!val) {
                FreePool(buf);
                return EFI_OUT_OF_RESOURCES;
        }

        *value = val;
        return EFI_SUCCESS;
}

EFI_STATUS efivar_get_int(CHAR16 *name, UINTN *i) {
        CHAR16 *val;
        EFI_STATUS err;

        err = efivar_get(name, &val);
        if (!EFI_ERROR(err)) {
                *i = Atoi(val);
                FreePool(val);
        }
        return err;
}

EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, CHAR16 *name, CHAR8 **buffer, UINTN *size) {
        CHAR8 *buf;
        UINTN l;
        EFI_STATUS err;

        l = sizeof(CHAR16 *) * EFI_MAXIMUM_VARIABLE_SIZE;
        buf = AllocatePool(l);
        if (!buf)
                return EFI_OUT_OF_RESOURCES;

        err = uefi_call_wrapper(RT->GetVariable, 5, name, (EFI_GUID *)vendor, NULL, &l, buf);
        if (!EFI_ERROR(err)) {
                *buffer = buf;
                if (size)
                        *size = l;
        } else
                FreePool(buf);
        return err;

}

VOID efivar_set_time_usec(CHAR16 *name, UINT64 usec) {
        CHAR16 str[32];

        if (usec == 0)
                usec = time_usec();
        if (usec == 0)
                return;

        SPrint(str, 32, L"%ld", usec);
        efivar_set(name, str, FALSE);
}

static INTN utf8_to_16(CHAR8 *stra, CHAR16 *c) {
        CHAR16 unichar;
        UINTN len;
        UINTN i;

        if (stra[0] < 0x80)
                len = 1;
        else if ((stra[0] & 0xe0) == 0xc0)
                len = 2;
        else if ((stra[0] & 0xf0) == 0xe0)
                len = 3;
        else if ((stra[0] & 0xf8) == 0xf0)
                len = 4;
        else if ((stra[0] & 0xfc) == 0xf8)
                len = 5;
        else if ((stra[0] & 0xfe) == 0xfc)
                len = 6;
        else
                return -1;

        switch (len) {
        case 1:
                unichar = stra[0];
                break;
        case 2:
                unichar = stra[0] & 0x1f;
                break;
        case 3:
                unichar = stra[0] & 0x0f;
                break;
        case 4:
                unichar = stra[0] & 0x07;
                break;
        case 5:
                unichar = stra[0] & 0x03;
                break;
        case 6:
                unichar = stra[0] & 0x01;
                break;
        }

        for (i = 1; i < len; i++) {
                if ((stra[i] & 0xc0) != 0x80)
                        return -1;
                unichar <<= 6;
                unichar |= stra[i] & 0x3f;
        }

        *c = unichar;
        return len;
}

CHAR16 *stra_to_str(CHAR8 *stra) {
        UINTN strlen;
        UINTN len;
        UINTN i;
        CHAR16 *str;

        len = strlena(stra);
        str = AllocatePool((len + 1) * sizeof(CHAR16));

        strlen = 0;
        i = 0;
        while (i < len) {
                INTN utf8len;

                utf8len = utf8_to_16(stra + i, str + strlen);
                if (utf8len <= 0) {
                        /* invalid utf8 sequence, skip the garbage */
                        i++;
                        continue;
                }

                strlen++;
                i += utf8len;
        }
        str[strlen] = '\0';
        return str;
}

CHAR16 *stra_to_path(CHAR8 *stra) {
        CHAR16 *str;
        UINTN strlen;
        UINTN len;
        UINTN i;

        len = strlena(stra);
        str = AllocatePool((len + 2) * sizeof(CHAR16));

        str[0] = '\\';
        strlen = 1;
        i = 0;
        while (i < len) {
                INTN utf8len;

                utf8len = utf8_to_16(stra + i, str + strlen);
                if (utf8len <= 0) {
                        /* invalid utf8 sequence, skip the garbage */
                        i++;
                        continue;
                }

                if (str[strlen] == '/')
                        str[strlen] = '\\';
                if (str[strlen] == '\\' && str[strlen-1] == '\\') {
                        /* skip double slashes */
                        i += utf8len;
                        continue;
                }

                strlen++;
                i += utf8len;
        }
        str[strlen] = '\0';
        return str;
}

CHAR8 *strchra(CHAR8 *s, CHAR8 c) {
        do {
                if (*s == c)
                        return s;
        } while (*s++);
        return NULL;
}

INTN file_read(EFI_FILE_HANDLE dir, CHAR16 *name, UINTN off, UINTN size, CHAR8 **content) {
        EFI_FILE_HANDLE handle;
        CHAR8 *buf;
        UINTN buflen;
        EFI_STATUS err;
        UINTN len;

        err = uefi_call_wrapper(dir->Open, 5, dir, &handle, name, EFI_FILE_MODE_READ, 0ULL);
        if (EFI_ERROR(err))
                return err;

        if (size == 0) {
                EFI_FILE_INFO *info;

                info = LibFileInfo(handle);
                buflen = info->FileSize+1;
                FreePool(info);
        } else
                buflen = size;

        if (off > 0) {
                err = uefi_call_wrapper(handle->SetPosition, 2, handle, off);
                if (EFI_ERROR(err))
                        return err;
        }

        buf = AllocatePool(buflen);
        err = uefi_call_wrapper(handle->Read, 3, handle, &buflen, buf);
        if (!EFI_ERROR(err)) {
                buf[buflen] = '\0';
                *content = buf;
                len = buflen;
        } else {
                len = err;
                FreePool(buf);
        }

        uefi_call_wrapper(handle->Close, 1, handle);
        return len;
}