xref: /openbmc/qemu/hw/riscv/boot.c (revision 6baabe5cf8d42ce6bc542fb3ec0bfc10c0ee6c5e)
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/loader.h"
26 #include "hw/riscv/boot.h"
27 #include "hw/boards.h"
28 #include "elf.h"
29 
30 #if defined(TARGET_RISCV32)
31 # define KERNEL_BOOT_ADDRESS 0x80400000
32 #else
33 # define KERNEL_BOOT_ADDRESS 0x80200000
34 #endif
35 
36 void riscv_find_and_load_firmware(MachineState *machine,
37                                   const char *default_machine_firmware,
38                                   hwaddr firmware_load_addr)
39 {
40     char *firmware_filename;
41 
42     if (!machine->firmware) {
43         /*
44          * The user didn't specify -bios.
45          * At the moment we default to loading nothing when this hapens.
46          * In the future this defaul will change to loading the prebuilt
47          * OpenSBI firmware. Let's warn the user and then continue.
48         */
49         warn_report("No -bios option specified. Not loading a firmware.");
50         warn_report("This default will change in QEMU 4.3. Please use the " \
51                     "-bios option to aviod breakages when this happens.");
52         warn_report("See QEMU's deprecation documentation for details");
53         return;
54     }
55 
56     if (!strcmp(machine->firmware, "default")) {
57         /*
58          * The user has specified "-bios default". That means we are going to
59          * load the OpenSBI binary included in the QEMU source.
60          *
61          * We can't load the binary by default as it will break existing users
62          * as users are already loading their own firmware.
63          *
64          * Let's try to get everyone to specify the -bios option at all times,
65          * so then in the future we can make "-bios default" the default option
66          * if no -bios option is set without breaking anything.
67          */
68         firmware_filename = qemu_find_file(QEMU_FILE_TYPE_BIOS,
69                                            default_machine_firmware);
70         if (firmware_filename == NULL) {
71             error_report("Unable to load the default RISC-V firmware \"%s\"",
72                          default_machine_firmware);
73             exit(1);
74         }
75     } else {
76         firmware_filename = machine->firmware;
77     }
78 
79     if (strcmp(firmware_filename, "none")) {
80         /* If not "none" load the firmware */
81         riscv_load_firmware(firmware_filename, firmware_load_addr);
82     }
83 
84     if (!strcmp(machine->firmware, "default")) {
85         g_free(firmware_filename);
86     }
87 }
88 
89 target_ulong riscv_load_firmware(const char *firmware_filename,
90                                  hwaddr firmware_load_addr)
91 {
92     uint64_t firmware_entry, firmware_start, firmware_end;
93 
94     if (load_elf(firmware_filename, NULL, NULL, NULL, &firmware_entry,
95                  &firmware_start, &firmware_end, 0, EM_RISCV, 1, 0) > 0) {
96         return firmware_entry;
97     }
98 
99     if (load_image_targphys_as(firmware_filename, firmware_load_addr,
100                                ram_size, NULL) > 0) {
101         return firmware_load_addr;
102     }
103 
104     error_report("could not load firmware '%s'", firmware_filename);
105     exit(1);
106 }
107 
108 target_ulong riscv_load_kernel(const char *kernel_filename)
109 {
110     uint64_t kernel_entry, kernel_high;
111 
112     if (load_elf(kernel_filename, NULL, NULL, NULL,
113                  &kernel_entry, NULL, &kernel_high, 0, EM_RISCV, 1, 0) > 0) {
114         return kernel_entry;
115     }
116 
117     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
118                        NULL, NULL, NULL) > 0) {
119         return kernel_entry;
120     }
121 
122     if (load_image_targphys_as(kernel_filename, KERNEL_BOOT_ADDRESS,
123                                ram_size, NULL) > 0) {
124         return KERNEL_BOOT_ADDRESS;
125     }
126 
127     error_report("could not load kernel '%s'", kernel_filename);
128     exit(1);
129 }
130 
131 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
132                          uint64_t kernel_entry, hwaddr *start)
133 {
134     int size;
135 
136     /*
137      * We want to put the initrd far enough into RAM that when the
138      * kernel is uncompressed it will not clobber the initrd. However
139      * on boards without much RAM we must ensure that we still leave
140      * enough room for a decent sized initrd, and on boards with large
141      * amounts of RAM we must avoid the initrd being so far up in RAM
142      * that it is outside lowmem and inaccessible to the kernel.
143      * So for boards with less  than 256MB of RAM we put the initrd
144      * halfway into RAM, and for boards with 256MB of RAM or more we put
145      * the initrd at 128MB.
146      */
147     *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
148 
149     size = load_ramdisk(filename, *start, mem_size - *start);
150     if (size == -1) {
151         size = load_image_targphys(filename, *start, mem_size - *start);
152         if (size == -1) {
153             error_report("could not load ramdisk '%s'", filename);
154             exit(1);
155         }
156     }
157 
158     return *start + size;
159 }
160