xref: /openbmc/qemu/hw/i386/pc_sysfw.c (revision d1fd31f8)
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 "hw/sysbus.h"
32 #include "hw/hw.h"
33 #include "hw/i386/pc.h"
34 #include "hw/boards.h"
35 #include "hw/loader.h"
36 #include "sysemu/sysemu.h"
37 #include "hw/block/flash.h"
38 #include "sysemu/kvm.h"
39 
40 #define BIOS_FILENAME "bios.bin"
41 
42 typedef struct PcSysFwDevice {
43     SysBusDevice busdev;
44     uint8_t isapc_ram_fw;
45 } PcSysFwDevice;
46 
47 static void pc_isa_bios_init(MemoryRegion *rom_memory,
48                              MemoryRegion *flash_mem,
49                              int ram_size)
50 {
51     int isa_bios_size;
52     MemoryRegion *isa_bios;
53     uint64_t flash_size;
54     void *flash_ptr, *isa_bios_ptr;
55 
56     flash_size = memory_region_size(flash_mem);
57 
58     /* map the last 128KB of the BIOS in ISA space */
59     isa_bios_size = MIN(flash_size, 128 * 1024);
60     isa_bios = g_malloc(sizeof(*isa_bios));
61     memory_region_init_ram(isa_bios, NULL, "isa-bios", isa_bios_size,
62                            &error_fatal);
63     memory_region_add_subregion_overlap(rom_memory,
64                                         0x100000 - isa_bios_size,
65                                         isa_bios,
66                                         1);
67 
68     /* copy ISA rom image from top of flash memory */
69     flash_ptr = memory_region_get_ram_ptr(flash_mem);
70     isa_bios_ptr = memory_region_get_ram_ptr(isa_bios);
71     memcpy(isa_bios_ptr,
72            ((uint8_t*)flash_ptr) + (flash_size - isa_bios_size),
73            isa_bios_size);
74 
75     memory_region_set_readonly(isa_bios, true);
76 }
77 
78 #define FLASH_MAP_UNIT_MAX 2
79 
80 /* We don't have a theoretically justifiable exact lower bound on the base
81  * address of any flash mapping. In practice, the IO-APIC MMIO range is
82  * [0xFEE00000..0xFEE01000[ -- see IO_APIC_DEFAULT_ADDRESS --, leaving free
83  * only 18MB-4KB below 4G. For now, restrict the cumulative mapping to 8MB in
84  * size.
85  */
86 #define FLASH_MAP_BASE_MIN ((hwaddr)(0x100000000ULL - 8*1024*1024))
87 
88 /* This function maps flash drives from 4G downward, in order of their unit
89  * numbers. The mapping starts at unit#0, with unit number increments of 1, and
90  * stops before the first missing flash drive, or before
91  * unit#FLASH_MAP_UNIT_MAX, whichever is reached first.
92  *
93  * Addressing within one flash drive is of course not reversed.
94  *
95  * An error message is printed and the process exits if:
96  * - the size of the backing file for a flash drive is non-positive, or not a
97  *   multiple of the required sector size, or
98  * - the current mapping's base address would fall below FLASH_MAP_BASE_MIN.
99  *
100  * The drive with unit#0 (if available) is mapped at the highest address, and
101  * it is passed to pc_isa_bios_init(). Merging several drives for isa-bios is
102  * not supported.
103  */
104 static void pc_system_flash_init(MemoryRegion *rom_memory)
105 {
106     int unit;
107     DriveInfo *pflash_drv;
108     BlockBackend *blk;
109     int64_t size;
110     char *fatal_errmsg = NULL;
111     hwaddr phys_addr = 0x100000000ULL;
112     int sector_bits, sector_size;
113     pflash_t *system_flash;
114     MemoryRegion *flash_mem;
115     char name[64];
116     void *flash_ptr;
117     int ret, flash_size;
118 
119     sector_bits = 12;
120     sector_size = 1 << sector_bits;
121 
122     for (unit = 0;
123          (unit < FLASH_MAP_UNIT_MAX &&
124           (pflash_drv = drive_get(IF_PFLASH, 0, unit)) != NULL);
125          ++unit) {
126         blk = blk_by_legacy_dinfo(pflash_drv);
127         size = blk_getlength(blk);
128         if (size < 0) {
129             fatal_errmsg = g_strdup_printf("failed to get backing file size");
130         } else if (size == 0) {
131             fatal_errmsg = g_strdup_printf("PC system firmware (pflash) "
132                                "cannot have zero size");
133         } else if ((size % sector_size) != 0) {
134             fatal_errmsg = g_strdup_printf("PC system firmware (pflash) "
135                                "must be a multiple of 0x%x", sector_size);
136         } else if (phys_addr < size || phys_addr - size < FLASH_MAP_BASE_MIN) {
137             fatal_errmsg = g_strdup_printf("oversized backing file, pflash "
138                                "segments cannot be mapped under "
139                                TARGET_FMT_plx, FLASH_MAP_BASE_MIN);
140         }
141         if (fatal_errmsg != NULL) {
142             Location loc;
143 
144             /* push a new, "none" location on the location stack; overwrite its
145              * contents with the location saved in the option; print the error
146              * (includes location); pop the top
147              */
148             loc_push_none(&loc);
149             if (pflash_drv->opts != NULL) {
150                 qemu_opts_loc_restore(pflash_drv->opts);
151             }
152             error_report("%s", fatal_errmsg);
153             loc_pop(&loc);
154             g_free(fatal_errmsg);
155             exit(1);
156         }
157 
158         phys_addr -= size;
159 
160         /* pflash_cfi01_register() creates a deep copy of the name */
161         snprintf(name, sizeof name, "system.flash%d", unit);
162         system_flash = pflash_cfi01_register(phys_addr, NULL /* qdev */, name,
163                                              size, blk, sector_size,
164                                              size >> sector_bits,
165                                              1      /* width */,
166                                              0x0000 /* id0 */,
167                                              0x0000 /* id1 */,
168                                              0x0000 /* id2 */,
169                                              0x0000 /* id3 */,
170                                              0      /* be */);
171         if (unit == 0) {
172             flash_mem = pflash_cfi01_get_memory(system_flash);
173             pc_isa_bios_init(rom_memory, flash_mem, size);
174 
175             /* Encrypt the pflash boot ROM */
176             if (kvm_memcrypt_enabled()) {
177                 flash_ptr = memory_region_get_ram_ptr(flash_mem);
178                 flash_size = memory_region_size(flash_mem);
179                 ret = kvm_memcrypt_encrypt_data(flash_ptr, flash_size);
180                 if (ret) {
181                     error_report("failed to encrypt pflash rom");
182                     exit(1);
183                 }
184             }
185         }
186     }
187 }
188 
189 static void old_pc_system_rom_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
190 {
191     char *filename;
192     MemoryRegion *bios, *isa_bios;
193     int bios_size, isa_bios_size;
194     int ret;
195 
196     /* BIOS load */
197     if (bios_name == NULL) {
198         bios_name = BIOS_FILENAME;
199     }
200     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
201     if (filename) {
202         bios_size = get_image_size(filename);
203     } else {
204         bios_size = -1;
205     }
206     if (bios_size <= 0 ||
207         (bios_size % 65536) != 0) {
208         goto bios_error;
209     }
210     bios = g_malloc(sizeof(*bios));
211     memory_region_init_ram(bios, NULL, "pc.bios", bios_size, &error_fatal);
212     if (!isapc_ram_fw) {
213         memory_region_set_readonly(bios, true);
214     }
215     ret = rom_add_file_fixed(bios_name, (uint32_t)(-bios_size), -1);
216     if (ret != 0) {
217     bios_error:
218         fprintf(stderr, "qemu: could not load PC BIOS '%s'\n", bios_name);
219         exit(1);
220     }
221     g_free(filename);
222 
223     /* map the last 128KB of the BIOS in ISA space */
224     isa_bios_size = bios_size;
225     if (isa_bios_size > (128 * 1024)) {
226         isa_bios_size = 128 * 1024;
227     }
228     isa_bios = g_malloc(sizeof(*isa_bios));
229     memory_region_init_alias(isa_bios, NULL, "isa-bios", bios,
230                              bios_size - isa_bios_size, isa_bios_size);
231     memory_region_add_subregion_overlap(rom_memory,
232                                         0x100000 - isa_bios_size,
233                                         isa_bios,
234                                         1);
235     if (!isapc_ram_fw) {
236         memory_region_set_readonly(isa_bios, true);
237     }
238 
239     /* map all the bios at the top of memory */
240     memory_region_add_subregion(rom_memory,
241                                 (uint32_t)(-bios_size),
242                                 bios);
243 }
244 
245 void pc_system_firmware_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
246 {
247     DriveInfo *pflash_drv;
248 
249     pflash_drv = drive_get(IF_PFLASH, 0, 0);
250 
251     if (isapc_ram_fw || pflash_drv == NULL) {
252         /* When a pflash drive is not found, use rom-mode */
253         old_pc_system_rom_init(rom_memory, isapc_ram_fw);
254         return;
255     }
256 
257     if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
258         /* Older KVM cannot execute from device memory. So, flash memory
259          * cannot be used unless the readonly memory kvm capability is present. */
260         fprintf(stderr, "qemu: pflash with kvm requires KVM readonly memory support\n");
261         exit(1);
262     }
263 
264     pc_system_flash_init(rom_memory);
265 }
266