xref: /openbmc/qemu/hw/riscv/boot.c (revision b326b6ea)
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 "hw/riscv/boot_opensbi.h"
29 #include "elf.h"
30 #include "sysemu/device_tree.h"
31 #include "sysemu/qtest.h"
32 
33 #include <libfdt.h>
34 
35 #if defined(TARGET_RISCV32)
36 #define fw_dynamic_info_data(__val)     cpu_to_le32(__val)
37 #else
38 #define fw_dynamic_info_data(__val)     cpu_to_le64(__val)
39 #endif
40 
41 bool riscv_is_32_bit(MachineState *machine)
42 {
43     if (!strncmp(machine->cpu_type, "rv32", 4)) {
44         return true;
45     } else {
46         return false;
47     }
48 }
49 
50 target_ulong riscv_calc_kernel_start_addr(MachineState *machine,
51                                           target_ulong firmware_end_addr) {
52     if (riscv_is_32_bit(machine)) {
53         return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
54     } else {
55         return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
56     }
57 }
58 
59 target_ulong riscv_find_and_load_firmware(MachineState *machine,
60                                           const char *default_machine_firmware,
61                                           hwaddr firmware_load_addr,
62                                           symbol_fn_t sym_cb)
63 {
64     char *firmware_filename = NULL;
65     target_ulong firmware_end_addr = firmware_load_addr;
66 
67     if ((!machine->firmware) || (!strcmp(machine->firmware, "default"))) {
68         /*
69          * The user didn't specify -bios, or has specified "-bios default".
70          * That means we are going to load the OpenSBI binary included in
71          * the QEMU source.
72          */
73         firmware_filename = riscv_find_firmware(default_machine_firmware);
74     } else if (strcmp(machine->firmware, "none")) {
75         firmware_filename = riscv_find_firmware(machine->firmware);
76     }
77 
78     if (firmware_filename) {
79         /* If not "none" load the firmware */
80         firmware_end_addr = riscv_load_firmware(firmware_filename,
81                                                 firmware_load_addr, sym_cb);
82         g_free(firmware_filename);
83     }
84 
85     return firmware_end_addr;
86 }
87 
88 char *riscv_find_firmware(const char *firmware_filename)
89 {
90     char *filename;
91 
92     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware_filename);
93     if (filename == NULL) {
94         if (!qtest_enabled()) {
95             /*
96              * We only ship plain binary bios images in the QEMU source.
97              * With Spike machine that uses ELF images as the default bios,
98              * running QEMU test will complain hence let's suppress the error
99              * report for QEMU testing.
100              */
101             error_report("Unable to load the RISC-V firmware \"%s\"",
102                          firmware_filename);
103             exit(1);
104         }
105     }
106 
107     return filename;
108 }
109 
110 target_ulong riscv_load_firmware(const char *firmware_filename,
111                                  hwaddr firmware_load_addr,
112                                  symbol_fn_t sym_cb)
113 {
114     uint64_t firmware_entry, firmware_size, firmware_end;
115 
116     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
117                          &firmware_entry, NULL, &firmware_end, NULL,
118                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
119         return firmware_end;
120     }
121 
122     firmware_size = load_image_targphys_as(firmware_filename,
123                                            firmware_load_addr,
124                                            current_machine->ram_size, NULL);
125 
126     if (firmware_size > 0) {
127         return firmware_load_addr + firmware_size;
128     }
129 
130     error_report("could not load firmware '%s'", firmware_filename);
131     exit(1);
132 }
133 
134 target_ulong riscv_load_kernel(const char *kernel_filename,
135                                target_ulong kernel_start_addr,
136                                symbol_fn_t sym_cb)
137 {
138     uint64_t kernel_entry;
139 
140     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
141                          &kernel_entry, NULL, NULL, NULL, 0,
142                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
143         return kernel_entry;
144     }
145 
146     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
147                        NULL, NULL, NULL) > 0) {
148         return kernel_entry;
149     }
150 
151     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
152                                current_machine->ram_size, NULL) > 0) {
153         return kernel_start_addr;
154     }
155 
156     error_report("could not load kernel '%s'", kernel_filename);
157     exit(1);
158 }
159 
160 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
161                          uint64_t kernel_entry, hwaddr *start)
162 {
163     int size;
164 
165     /*
166      * We want to put the initrd far enough into RAM that when the
167      * kernel is uncompressed it will not clobber the initrd. However
168      * on boards without much RAM we must ensure that we still leave
169      * enough room for a decent sized initrd, and on boards with large
170      * amounts of RAM we must avoid the initrd being so far up in RAM
171      * that it is outside lowmem and inaccessible to the kernel.
172      * So for boards with less  than 256MB of RAM we put the initrd
173      * halfway into RAM, and for boards with 256MB of RAM or more we put
174      * the initrd at 128MB.
175      */
176     *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
177 
178     size = load_ramdisk(filename, *start, mem_size - *start);
179     if (size == -1) {
180         size = load_image_targphys(filename, *start, mem_size - *start);
181         if (size == -1) {
182             error_report("could not load ramdisk '%s'", filename);
183             exit(1);
184         }
185     }
186 
187     return *start + size;
188 }
189 
190 uint32_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
191 {
192     uint32_t temp, fdt_addr;
193     hwaddr dram_end = dram_base + mem_size;
194     int fdtsize = fdt_totalsize(fdt);
195 
196     if (fdtsize <= 0) {
197         error_report("invalid device-tree");
198         exit(1);
199     }
200 
201     /*
202      * We should put fdt as far as possible to avoid kernel/initrd overwriting
203      * its content. But it should be addressable by 32 bit system as well.
204      * Thus, put it at an aligned address that less than fdt size from end of
205      * dram or 4GB whichever is lesser.
206      */
207     temp = MIN(dram_end, 4096 * MiB);
208     fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
209 
210     fdt_pack(fdt);
211     /* copy in the device tree */
212     qemu_fdt_dumpdtb(fdt, fdtsize);
213 
214     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
215                           &address_space_memory);
216 
217     return fdt_addr;
218 }
219 
220 void riscv_rom_copy_firmware_info(hwaddr rom_base, hwaddr rom_size,
221                               uint32_t reset_vec_size, uint64_t kernel_entry)
222 {
223     struct fw_dynamic_info dinfo;
224     size_t dinfo_len;
225 
226     dinfo.magic = fw_dynamic_info_data(FW_DYNAMIC_INFO_MAGIC_VALUE);
227     dinfo.version = fw_dynamic_info_data(FW_DYNAMIC_INFO_VERSION);
228     dinfo.next_mode = fw_dynamic_info_data(FW_DYNAMIC_INFO_NEXT_MODE_S);
229     dinfo.next_addr = fw_dynamic_info_data(kernel_entry);
230     dinfo.options = 0;
231     dinfo.boot_hart = 0;
232     dinfo_len = sizeof(dinfo);
233 
234     /**
235      * copy the dynamic firmware info. This information is specific to
236      * OpenSBI but doesn't break any other firmware as long as they don't
237      * expect any certain value in "a2" register.
238      */
239     if (dinfo_len > (rom_size - reset_vec_size)) {
240         error_report("not enough space to store dynamic firmware info");
241         exit(1);
242     }
243 
244     rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
245                            rom_base + reset_vec_size,
246                            &address_space_memory);
247 }
248 
249 void riscv_setup_rom_reset_vec(hwaddr start_addr, hwaddr rom_base,
250                                hwaddr rom_size, uint64_t kernel_entry,
251                                uint32_t fdt_load_addr, void *fdt)
252 {
253     int i;
254     uint32_t start_addr_hi32 = 0x00000000;
255 
256     #if defined(TARGET_RISCV64)
257     start_addr_hi32 = start_addr >> 32;
258     #endif
259     /* reset vector */
260     uint32_t reset_vec[10] = {
261         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
262         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
263         0xf1402573,                  /*     csrr   a0, mhartid  */
264 #if defined(TARGET_RISCV32)
265         0x0202a583,                  /*     lw     a1, 32(t0) */
266         0x0182a283,                  /*     lw     t0, 24(t0) */
267 #elif defined(TARGET_RISCV64)
268         0x0202b583,                  /*     ld     a1, 32(t0) */
269         0x0182b283,                  /*     ld     t0, 24(t0) */
270 #endif
271         0x00028067,                  /*     jr     t0 */
272         start_addr,                  /* start: .dword */
273         start_addr_hi32,
274         fdt_load_addr,               /* fdt_laddr: .dword */
275         0x00000000,
276                                      /* fw_dyn: */
277     };
278 
279     /* copy in the reset vector in little_endian byte order */
280     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
281         reset_vec[i] = cpu_to_le32(reset_vec[i]);
282     }
283     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
284                           rom_base, &address_space_memory);
285     riscv_rom_copy_firmware_info(rom_base, rom_size, sizeof(reset_vec),
286                                  kernel_entry);
287 
288     return;
289 }
290