xref: /openbmc/qemu/hw/riscv/boot.c (revision 59a3a1c0)
1 /*
2  * QEMU RISC-V Boot Helper
3  *
4  * Copyright (c) 2017 SiFive, Inc.
5  * Copyright (c) 2019 Alistair Francis <alistair.francis@wdc.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2 or later, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu-common.h"
22 #include "qemu/units.h"
23 #include "qemu/error-report.h"
24 #include "exec/cpu-defs.h"
25 #include "hw/boards.h"
26 #include "hw/loader.h"
27 #include "hw/riscv/boot.h"
28 #include "elf.h"
29 #include "sysemu/qtest.h"
30 
31 #if defined(TARGET_RISCV32)
32 # define KERNEL_BOOT_ADDRESS 0x80400000
33 #else
34 # define KERNEL_BOOT_ADDRESS 0x80200000
35 #endif
36 
37 void riscv_find_and_load_firmware(MachineState *machine,
38                                   const char *default_machine_firmware,
39                                   hwaddr firmware_load_addr)
40 {
41     char *firmware_filename;
42 
43     if (!machine->firmware) {
44         /*
45          * The user didn't specify -bios.
46          * At the moment we default to loading nothing when this hapens.
47          * In the future this defaul will change to loading the prebuilt
48          * OpenSBI firmware. Let's warn the user and then continue.
49         */
50         if (!qtest_enabled()) {
51             warn_report("No -bios option specified. Not loading a firmware.");
52             warn_report("This default will change in a future QEMU release. " \
53                         "Please use the -bios option to avoid breakages when "\
54                         "this happens.");
55             warn_report("See QEMU's deprecation documentation for details.");
56         }
57         return;
58     }
59 
60     if (!strcmp(machine->firmware, "default")) {
61         /*
62          * The user has specified "-bios default". That means we are going to
63          * load the OpenSBI binary included in the QEMU source.
64          *
65          * We can't load the binary by default as it will break existing users
66          * as users are already loading their own firmware.
67          *
68          * Let's try to get everyone to specify the -bios option at all times,
69          * so then in the future we can make "-bios default" the default option
70          * if no -bios option is set without breaking anything.
71          */
72         firmware_filename = qemu_find_file(QEMU_FILE_TYPE_BIOS,
73                                            default_machine_firmware);
74         if (firmware_filename == NULL) {
75             error_report("Unable to load the default RISC-V firmware \"%s\"",
76                          default_machine_firmware);
77             exit(1);
78         }
79     } else {
80         firmware_filename = machine->firmware;
81     }
82 
83     if (strcmp(firmware_filename, "none")) {
84         /* If not "none" load the firmware */
85         riscv_load_firmware(firmware_filename, firmware_load_addr);
86     }
87 
88     if (!strcmp(machine->firmware, "default")) {
89         g_free(firmware_filename);
90     }
91 }
92 
93 target_ulong riscv_load_firmware(const char *firmware_filename,
94                                  hwaddr firmware_load_addr)
95 {
96     uint64_t firmware_entry, firmware_start, firmware_end;
97 
98     if (load_elf(firmware_filename, NULL, NULL, NULL, &firmware_entry,
99                  &firmware_start, &firmware_end, 0, EM_RISCV, 1, 0) > 0) {
100         return firmware_entry;
101     }
102 
103     if (load_image_targphys_as(firmware_filename, firmware_load_addr,
104                                ram_size, NULL) > 0) {
105         return firmware_load_addr;
106     }
107 
108     error_report("could not load firmware '%s'", firmware_filename);
109     exit(1);
110 }
111 
112 target_ulong riscv_load_kernel(const char *kernel_filename)
113 {
114     uint64_t kernel_entry, kernel_high;
115 
116     if (load_elf(kernel_filename, NULL, NULL, NULL,
117                  &kernel_entry, NULL, &kernel_high, 0, EM_RISCV, 1, 0) > 0) {
118         return kernel_entry;
119     }
120 
121     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
122                        NULL, NULL, NULL) > 0) {
123         return kernel_entry;
124     }
125 
126     if (load_image_targphys_as(kernel_filename, KERNEL_BOOT_ADDRESS,
127                                ram_size, NULL) > 0) {
128         return KERNEL_BOOT_ADDRESS;
129     }
130 
131     error_report("could not load kernel '%s'", kernel_filename);
132     exit(1);
133 }
134 
135 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
136                          uint64_t kernel_entry, hwaddr *start)
137 {
138     int size;
139 
140     /*
141      * We want to put the initrd far enough into RAM that when the
142      * kernel is uncompressed it will not clobber the initrd. However
143      * on boards without much RAM we must ensure that we still leave
144      * enough room for a decent sized initrd, and on boards with large
145      * amounts of RAM we must avoid the initrd being so far up in RAM
146      * that it is outside lowmem and inaccessible to the kernel.
147      * So for boards with less  than 256MB of RAM we put the initrd
148      * halfway into RAM, and for boards with 256MB of RAM or more we put
149      * the initrd at 128MB.
150      */
151     *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
152 
153     size = load_ramdisk(filename, *start, mem_size - *start);
154     if (size == -1) {
155         size = load_image_targphys(filename, *start, mem_size - *start);
156         if (size == -1) {
157             error_report("could not load ramdisk '%s'", filename);
158             exit(1);
159         }
160     }
161 
162     return *start + size;
163 }
164