xref: /openbmc/qemu/hw/i386/pc_sysfw.c (revision c40d4792)
1 /*
2  * QEMU PC System Firmware
3  *
4  * Copyright (c) 2003-2004 Fabrice Bellard
5  * Copyright (c) 2011-2012 Intel Corporation
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "qapi/error.h"
28 #include "sysemu/block-backend.h"
29 #include "qemu/error-report.h"
30 #include "qemu/option.h"
31 #include "qemu/units.h"
32 #include "hw/sysbus.h"
33 #include "hw/hw.h"
34 #include "hw/i386/pc.h"
35 #include "hw/boards.h"
36 #include "hw/loader.h"
37 #include "sysemu/sysemu.h"
38 #include "hw/block/flash.h"
39 #include "sysemu/kvm.h"
40 
41 #define BIOS_FILENAME "bios.bin"
42 
43 typedef struct PcSysFwDevice {
44     SysBusDevice busdev;
45     uint8_t isapc_ram_fw;
46 } PcSysFwDevice;
47 
48 static void pc_isa_bios_init(MemoryRegion *rom_memory,
49                              MemoryRegion *flash_mem,
50                              int ram_size)
51 {
52     int isa_bios_size;
53     MemoryRegion *isa_bios;
54     uint64_t flash_size;
55     void *flash_ptr, *isa_bios_ptr;
56 
57     flash_size = memory_region_size(flash_mem);
58 
59     /* map the last 128KB of the BIOS in ISA space */
60     isa_bios_size = MIN(flash_size, 128 * KiB);
61     isa_bios = g_malloc(sizeof(*isa_bios));
62     memory_region_init_ram(isa_bios, NULL, "isa-bios", isa_bios_size,
63                            &error_fatal);
64     memory_region_add_subregion_overlap(rom_memory,
65                                         0x100000 - isa_bios_size,
66                                         isa_bios,
67                                         1);
68 
69     /* copy ISA rom image from top of flash memory */
70     flash_ptr = memory_region_get_ram_ptr(flash_mem);
71     isa_bios_ptr = memory_region_get_ram_ptr(isa_bios);
72     memcpy(isa_bios_ptr,
73            ((uint8_t*)flash_ptr) + (flash_size - isa_bios_size),
74            isa_bios_size);
75 
76     memory_region_set_readonly(isa_bios, true);
77 }
78 
79 #define FLASH_MAP_UNIT_MAX 2
80 
81 /* We don't have a theoretically justifiable exact lower bound on the base
82  * address of any flash mapping. In practice, the IO-APIC MMIO range is
83  * [0xFEE00000..0xFEE01000[ -- see IO_APIC_DEFAULT_ADDRESS --, leaving free
84  * only 18MB-4KB below 4G. For now, restrict the cumulative mapping to 8MB in
85  * size.
86  */
87 #define FLASH_MAP_BASE_MIN ((hwaddr)(4 * GiB - 8 * MiB))
88 
89 /* This function maps flash drives from 4G downward, in order of their unit
90  * numbers. The mapping starts at unit#0, with unit number increments of 1, and
91  * stops before the first missing flash drive, or before
92  * unit#FLASH_MAP_UNIT_MAX, whichever is reached first.
93  *
94  * Addressing within one flash drive is of course not reversed.
95  *
96  * An error message is printed and the process exits if:
97  * - the size of the backing file for a flash drive is non-positive, or not a
98  *   multiple of the required sector size, or
99  * - the current mapping's base address would fall below FLASH_MAP_BASE_MIN.
100  *
101  * The drive with unit#0 (if available) is mapped at the highest address, and
102  * it is passed to pc_isa_bios_init(). Merging several drives for isa-bios is
103  * not supported.
104  */
105 static void pc_system_flash_init(MemoryRegion *rom_memory)
106 {
107     int unit;
108     DriveInfo *pflash_drv;
109     BlockBackend *blk;
110     int64_t size;
111     char *fatal_errmsg = NULL;
112     hwaddr phys_addr = 0x100000000ULL;
113     int sector_bits, sector_size;
114     pflash_t *system_flash;
115     MemoryRegion *flash_mem;
116     char name[64];
117     void *flash_ptr;
118     int ret, flash_size;
119 
120     sector_bits = 12;
121     sector_size = 1 << sector_bits;
122 
123     for (unit = 0;
124          (unit < FLASH_MAP_UNIT_MAX &&
125           (pflash_drv = drive_get(IF_PFLASH, 0, unit)) != NULL);
126          ++unit) {
127         blk = blk_by_legacy_dinfo(pflash_drv);
128         size = blk_getlength(blk);
129         if (size < 0) {
130             fatal_errmsg = g_strdup_printf("failed to get backing file size");
131         } else if (size == 0) {
132             fatal_errmsg = g_strdup_printf("PC system firmware (pflash) "
133                                "cannot have zero size");
134         } else if ((size % sector_size) != 0) {
135             fatal_errmsg = g_strdup_printf("PC system firmware (pflash) "
136                                "must be a multiple of 0x%x", sector_size);
137         } else if (phys_addr < size || phys_addr - size < FLASH_MAP_BASE_MIN) {
138             fatal_errmsg = g_strdup_printf("oversized backing file, pflash "
139                                "segments cannot be mapped under "
140                                TARGET_FMT_plx, FLASH_MAP_BASE_MIN);
141         }
142         if (fatal_errmsg != NULL) {
143             Location loc;
144 
145             /* push a new, "none" location on the location stack; overwrite its
146              * contents with the location saved in the option; print the error
147              * (includes location); pop the top
148              */
149             loc_push_none(&loc);
150             if (pflash_drv->opts != NULL) {
151                 qemu_opts_loc_restore(pflash_drv->opts);
152             }
153             error_report("%s", fatal_errmsg);
154             loc_pop(&loc);
155             g_free(fatal_errmsg);
156             exit(1);
157         }
158 
159         phys_addr -= size;
160 
161         /* pflash_cfi01_register() creates a deep copy of the name */
162         snprintf(name, sizeof name, "system.flash%d", unit);
163         system_flash = pflash_cfi01_register(phys_addr, NULL /* qdev */, name,
164                                              size, blk, sector_size,
165                                              size >> sector_bits,
166                                              1      /* width */,
167                                              0x0000 /* id0 */,
168                                              0x0000 /* id1 */,
169                                              0x0000 /* id2 */,
170                                              0x0000 /* id3 */,
171                                              0      /* be */);
172         if (unit == 0) {
173             flash_mem = pflash_cfi01_get_memory(system_flash);
174             pc_isa_bios_init(rom_memory, flash_mem, size);
175 
176             /* Encrypt the pflash boot ROM */
177             if (kvm_memcrypt_enabled()) {
178                 flash_ptr = memory_region_get_ram_ptr(flash_mem);
179                 flash_size = memory_region_size(flash_mem);
180                 ret = kvm_memcrypt_encrypt_data(flash_ptr, flash_size);
181                 if (ret) {
182                     error_report("failed to encrypt pflash rom");
183                     exit(1);
184                 }
185             }
186         }
187     }
188 }
189 
190 static void old_pc_system_rom_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
191 {
192     char *filename;
193     MemoryRegion *bios, *isa_bios;
194     int bios_size, isa_bios_size;
195     int ret;
196 
197     /* BIOS load */
198     if (bios_name == NULL) {
199         bios_name = BIOS_FILENAME;
200     }
201     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
202     if (filename) {
203         bios_size = get_image_size(filename);
204     } else {
205         bios_size = -1;
206     }
207     if (bios_size <= 0 ||
208         (bios_size % 65536) != 0) {
209         goto bios_error;
210     }
211     bios = g_malloc(sizeof(*bios));
212     memory_region_init_ram(bios, NULL, "pc.bios", bios_size, &error_fatal);
213     if (!isapc_ram_fw) {
214         memory_region_set_readonly(bios, true);
215     }
216     ret = rom_add_file_fixed(bios_name, (uint32_t)(-bios_size), -1);
217     if (ret != 0) {
218     bios_error:
219         fprintf(stderr, "qemu: could not load PC BIOS '%s'\n", bios_name);
220         exit(1);
221     }
222     g_free(filename);
223 
224     /* map the last 128KB of the BIOS in ISA space */
225     isa_bios_size = MIN(bios_size, 128 * KiB);
226     isa_bios = g_malloc(sizeof(*isa_bios));
227     memory_region_init_alias(isa_bios, NULL, "isa-bios", bios,
228                              bios_size - isa_bios_size, isa_bios_size);
229     memory_region_add_subregion_overlap(rom_memory,
230                                         0x100000 - isa_bios_size,
231                                         isa_bios,
232                                         1);
233     if (!isapc_ram_fw) {
234         memory_region_set_readonly(isa_bios, true);
235     }
236 
237     /* map all the bios at the top of memory */
238     memory_region_add_subregion(rom_memory,
239                                 (uint32_t)(-bios_size),
240                                 bios);
241 }
242 
243 void pc_system_firmware_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
244 {
245     DriveInfo *pflash_drv;
246 
247     pflash_drv = drive_get(IF_PFLASH, 0, 0);
248 
249     if (isapc_ram_fw || pflash_drv == NULL) {
250         /* When a pflash drive is not found, use rom-mode */
251         old_pc_system_rom_init(rom_memory, isapc_ram_fw);
252         return;
253     }
254 
255     if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
256         /* Older KVM cannot execute from device memory. So, flash memory
257          * cannot be used unless the readonly memory kvm capability is present. */
258         fprintf(stderr, "qemu: pflash with kvm requires KVM readonly memory support\n");
259         exit(1);
260     }
261 
262     pc_system_flash_init(rom_memory);
263 }
264