xref: /openbmc/qemu/hw/riscv/boot.c (revision 5b6c291b)
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/datadir.h"
23 #include "qemu/units.h"
24 #include "qemu/error-report.h"
25 #include "exec/cpu-defs.h"
26 #include "hw/boards.h"
27 #include "hw/loader.h"
28 #include "hw/riscv/boot.h"
29 #include "hw/riscv/boot_opensbi.h"
30 #include "elf.h"
31 #include "sysemu/device_tree.h"
32 #include "sysemu/qtest.h"
33 
34 #include <libfdt.h>
35 
36 bool riscv_is_32_bit(MachineState *machine)
37 {
38     /*
39      * To determine if the CPU is 32-bit we need to check a few different CPUs.
40      *
41      * If the CPU starts with rv32
42      * If the CPU is a sifive 3 seriries CPU (E31, U34)
43      * If it's the Ibex CPU
44      */
45     if (!strncmp(machine->cpu_type, "rv32", 4) ||
46         (!strncmp(machine->cpu_type, "sifive", 6) &&
47             machine->cpu_type[8] == '3') ||
48         !strncmp(machine->cpu_type, "lowrisc-ibex", 12)) {
49         return true;
50     } else {
51         return false;
52     }
53 }
54 
55 target_ulong riscv_calc_kernel_start_addr(MachineState *machine,
56                                           target_ulong firmware_end_addr) {
57     if (riscv_is_32_bit(machine)) {
58         return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
59     } else {
60         return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
61     }
62 }
63 
64 target_ulong riscv_find_and_load_firmware(MachineState *machine,
65                                           const char *default_machine_firmware,
66                                           hwaddr firmware_load_addr,
67                                           symbol_fn_t sym_cb)
68 {
69     char *firmware_filename = NULL;
70     target_ulong firmware_end_addr = firmware_load_addr;
71 
72     if ((!machine->firmware) || (!strcmp(machine->firmware, "default"))) {
73         /*
74          * The user didn't specify -bios, or has specified "-bios default".
75          * That means we are going to load the OpenSBI binary included in
76          * the QEMU source.
77          */
78         firmware_filename = riscv_find_firmware(default_machine_firmware);
79     } else if (strcmp(machine->firmware, "none")) {
80         firmware_filename = riscv_find_firmware(machine->firmware);
81     }
82 
83     if (firmware_filename) {
84         /* If not "none" load the firmware */
85         firmware_end_addr = riscv_load_firmware(firmware_filename,
86                                                 firmware_load_addr, sym_cb);
87         g_free(firmware_filename);
88     }
89 
90     return firmware_end_addr;
91 }
92 
93 char *riscv_find_firmware(const char *firmware_filename)
94 {
95     char *filename;
96 
97     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware_filename);
98     if (filename == NULL) {
99         if (!qtest_enabled()) {
100             /*
101              * We only ship plain binary bios images in the QEMU source.
102              * With Spike machine that uses ELF images as the default bios,
103              * running QEMU test will complain hence let's suppress the error
104              * report for QEMU testing.
105              */
106             error_report("Unable to load the RISC-V firmware \"%s\"",
107                          firmware_filename);
108             exit(1);
109         }
110     }
111 
112     return filename;
113 }
114 
115 target_ulong riscv_load_firmware(const char *firmware_filename,
116                                  hwaddr firmware_load_addr,
117                                  symbol_fn_t sym_cb)
118 {
119     uint64_t firmware_entry, firmware_size, firmware_end;
120 
121     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
122                          &firmware_entry, NULL, &firmware_end, NULL,
123                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
124         return firmware_end;
125     }
126 
127     firmware_size = load_image_targphys_as(firmware_filename,
128                                            firmware_load_addr,
129                                            current_machine->ram_size, NULL);
130 
131     if (firmware_size > 0) {
132         return firmware_load_addr + firmware_size;
133     }
134 
135     error_report("could not load firmware '%s'", firmware_filename);
136     exit(1);
137 }
138 
139 target_ulong riscv_load_kernel(const char *kernel_filename,
140                                target_ulong kernel_start_addr,
141                                symbol_fn_t sym_cb)
142 {
143     uint64_t kernel_entry;
144 
145     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
146                          &kernel_entry, NULL, NULL, NULL, 0,
147                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
148         return kernel_entry;
149     }
150 
151     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
152                        NULL, NULL, NULL) > 0) {
153         return kernel_entry;
154     }
155 
156     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
157                                current_machine->ram_size, NULL) > 0) {
158         return kernel_start_addr;
159     }
160 
161     error_report("could not load kernel '%s'", kernel_filename);
162     exit(1);
163 }
164 
165 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
166                          uint64_t kernel_entry, hwaddr *start)
167 {
168     int size;
169 
170     /*
171      * We want to put the initrd far enough into RAM that when the
172      * kernel is uncompressed it will not clobber the initrd. However
173      * on boards without much RAM we must ensure that we still leave
174      * enough room for a decent sized initrd, and on boards with large
175      * amounts of RAM we must avoid the initrd being so far up in RAM
176      * that it is outside lowmem and inaccessible to the kernel.
177      * So for boards with less  than 256MB of RAM we put the initrd
178      * halfway into RAM, and for boards with 256MB of RAM or more we put
179      * the initrd at 128MB.
180      */
181     *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
182 
183     size = load_ramdisk(filename, *start, mem_size - *start);
184     if (size == -1) {
185         size = load_image_targphys(filename, *start, mem_size - *start);
186         if (size == -1) {
187             error_report("could not load ramdisk '%s'", filename);
188             exit(1);
189         }
190     }
191 
192     return *start + size;
193 }
194 
195 uint32_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
196 {
197     uint32_t temp, fdt_addr;
198     hwaddr dram_end = dram_base + mem_size;
199     int fdtsize = fdt_totalsize(fdt);
200 
201     if (fdtsize <= 0) {
202         error_report("invalid device-tree");
203         exit(1);
204     }
205 
206     /*
207      * We should put fdt as far as possible to avoid kernel/initrd overwriting
208      * its content. But it should be addressable by 32 bit system as well.
209      * Thus, put it at an aligned address that less than fdt size from end of
210      * dram or 4GB whichever is lesser.
211      */
212     temp = MIN(dram_end, 4096 * MiB);
213     fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
214 
215     fdt_pack(fdt);
216     /* copy in the device tree */
217     qemu_fdt_dumpdtb(fdt, fdtsize);
218 
219     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
220                           &address_space_memory);
221 
222     return fdt_addr;
223 }
224 
225 void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
226                                   hwaddr rom_size, uint32_t reset_vec_size,
227                                   uint64_t kernel_entry)
228 {
229     struct fw_dynamic_info dinfo;
230     size_t dinfo_len;
231 
232     if (sizeof(dinfo.magic) == 4) {
233         dinfo.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
234         dinfo.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
235         dinfo.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
236         dinfo.next_addr = cpu_to_le32(kernel_entry);
237     } else {
238         dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
239         dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
240         dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
241         dinfo.next_addr = cpu_to_le64(kernel_entry);
242     }
243     dinfo.options = 0;
244     dinfo.boot_hart = 0;
245     dinfo_len = sizeof(dinfo);
246 
247     /**
248      * copy the dynamic firmware info. This information is specific to
249      * OpenSBI but doesn't break any other firmware as long as they don't
250      * expect any certain value in "a2" register.
251      */
252     if (dinfo_len > (rom_size - reset_vec_size)) {
253         error_report("not enough space to store dynamic firmware info");
254         exit(1);
255     }
256 
257     rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
258                            rom_base + reset_vec_size,
259                            &address_space_memory);
260 }
261 
262 void riscv_setup_rom_reset_vec(MachineState *machine, hwaddr start_addr,
263                                hwaddr rom_base, hwaddr rom_size,
264                                uint64_t kernel_entry,
265                                uint32_t fdt_load_addr, void *fdt)
266 {
267     int i;
268     uint32_t start_addr_hi32 = 0x00000000;
269 
270     if (!riscv_is_32_bit(machine)) {
271         start_addr_hi32 = start_addr >> 32;
272     }
273     /* reset vector */
274     uint32_t reset_vec[10] = {
275         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
276         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
277         0xf1402573,                  /*     csrr   a0, mhartid  */
278         0,
279         0,
280         0x00028067,                  /*     jr     t0 */
281         start_addr,                  /* start: .dword */
282         start_addr_hi32,
283         fdt_load_addr,               /* fdt_laddr: .dword */
284         0x00000000,
285                                      /* fw_dyn: */
286     };
287     if (riscv_is_32_bit(machine)) {
288         reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
289         reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
290     } else {
291         reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
292         reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
293     }
294 
295     /* copy in the reset vector in little_endian byte order */
296     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
297         reset_vec[i] = cpu_to_le32(reset_vec[i]);
298     }
299     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
300                           rom_base, &address_space_memory);
301     riscv_rom_copy_firmware_info(machine, rom_base, rom_size, sizeof(reset_vec),
302                                  kernel_entry);
303 
304     return;
305 }
306