xref: /openbmc/qemu/hw/riscv/boot.c (revision c0a635f3)
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 #if defined(TARGET_RISCV32)
37 #define fw_dynamic_info_data(__val)     cpu_to_le32(__val)
38 #else
39 #define fw_dynamic_info_data(__val)     cpu_to_le64(__val)
40 #endif
41 
42 bool riscv_is_32_bit(MachineState *machine)
43 {
44     /*
45      * To determine if the CPU is 32-bit we need to check a few different CPUs.
46      *
47      * If the CPU starts with rv32
48      * If the CPU is a sifive 3 seriries CPU (E31, U34)
49      * If it's the Ibex CPU
50      */
51     if (!strncmp(machine->cpu_type, "rv32", 4) ||
52         (!strncmp(machine->cpu_type, "sifive", 6) &&
53             machine->cpu_type[8] == '3') ||
54         !strncmp(machine->cpu_type, "lowrisc-ibex", 12)) {
55         return true;
56     } else {
57         return false;
58     }
59 }
60 
61 target_ulong riscv_calc_kernel_start_addr(MachineState *machine,
62                                           target_ulong firmware_end_addr) {
63     if (riscv_is_32_bit(machine)) {
64         return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
65     } else {
66         return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
67     }
68 }
69 
70 target_ulong riscv_find_and_load_firmware(MachineState *machine,
71                                           const char *default_machine_firmware,
72                                           hwaddr firmware_load_addr,
73                                           symbol_fn_t sym_cb)
74 {
75     char *firmware_filename = NULL;
76     target_ulong firmware_end_addr = firmware_load_addr;
77 
78     if ((!machine->firmware) || (!strcmp(machine->firmware, "default"))) {
79         /*
80          * The user didn't specify -bios, or has specified "-bios default".
81          * That means we are going to load the OpenSBI binary included in
82          * the QEMU source.
83          */
84         firmware_filename = riscv_find_firmware(default_machine_firmware);
85     } else if (strcmp(machine->firmware, "none")) {
86         firmware_filename = riscv_find_firmware(machine->firmware);
87     }
88 
89     if (firmware_filename) {
90         /* If not "none" load the firmware */
91         firmware_end_addr = riscv_load_firmware(firmware_filename,
92                                                 firmware_load_addr, sym_cb);
93         g_free(firmware_filename);
94     }
95 
96     return firmware_end_addr;
97 }
98 
99 char *riscv_find_firmware(const char *firmware_filename)
100 {
101     char *filename;
102 
103     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware_filename);
104     if (filename == NULL) {
105         if (!qtest_enabled()) {
106             /*
107              * We only ship plain binary bios images in the QEMU source.
108              * With Spike machine that uses ELF images as the default bios,
109              * running QEMU test will complain hence let's suppress the error
110              * report for QEMU testing.
111              */
112             error_report("Unable to load the RISC-V firmware \"%s\"",
113                          firmware_filename);
114             exit(1);
115         }
116     }
117 
118     return filename;
119 }
120 
121 target_ulong riscv_load_firmware(const char *firmware_filename,
122                                  hwaddr firmware_load_addr,
123                                  symbol_fn_t sym_cb)
124 {
125     uint64_t firmware_entry, firmware_size, firmware_end;
126 
127     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
128                          &firmware_entry, NULL, &firmware_end, NULL,
129                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
130         return firmware_end;
131     }
132 
133     firmware_size = load_image_targphys_as(firmware_filename,
134                                            firmware_load_addr,
135                                            current_machine->ram_size, NULL);
136 
137     if (firmware_size > 0) {
138         return firmware_load_addr + firmware_size;
139     }
140 
141     error_report("could not load firmware '%s'", firmware_filename);
142     exit(1);
143 }
144 
145 target_ulong riscv_load_kernel(const char *kernel_filename,
146                                target_ulong kernel_start_addr,
147                                symbol_fn_t sym_cb)
148 {
149     uint64_t kernel_entry;
150 
151     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
152                          &kernel_entry, NULL, NULL, NULL, 0,
153                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
154         return kernel_entry;
155     }
156 
157     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
158                        NULL, NULL, NULL) > 0) {
159         return kernel_entry;
160     }
161 
162     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
163                                current_machine->ram_size, NULL) > 0) {
164         return kernel_start_addr;
165     }
166 
167     error_report("could not load kernel '%s'", kernel_filename);
168     exit(1);
169 }
170 
171 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
172                          uint64_t kernel_entry, hwaddr *start)
173 {
174     int size;
175 
176     /*
177      * We want to put the initrd far enough into RAM that when the
178      * kernel is uncompressed it will not clobber the initrd. However
179      * on boards without much RAM we must ensure that we still leave
180      * enough room for a decent sized initrd, and on boards with large
181      * amounts of RAM we must avoid the initrd being so far up in RAM
182      * that it is outside lowmem and inaccessible to the kernel.
183      * So for boards with less  than 256MB of RAM we put the initrd
184      * halfway into RAM, and for boards with 256MB of RAM or more we put
185      * the initrd at 128MB.
186      */
187     *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
188 
189     size = load_ramdisk(filename, *start, mem_size - *start);
190     if (size == -1) {
191         size = load_image_targphys(filename, *start, mem_size - *start);
192         if (size == -1) {
193             error_report("could not load ramdisk '%s'", filename);
194             exit(1);
195         }
196     }
197 
198     return *start + size;
199 }
200 
201 uint32_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
202 {
203     uint32_t temp, fdt_addr;
204     hwaddr dram_end = dram_base + mem_size;
205     int fdtsize = fdt_totalsize(fdt);
206 
207     if (fdtsize <= 0) {
208         error_report("invalid device-tree");
209         exit(1);
210     }
211 
212     /*
213      * We should put fdt as far as possible to avoid kernel/initrd overwriting
214      * its content. But it should be addressable by 32 bit system as well.
215      * Thus, put it at an aligned address that less than fdt size from end of
216      * dram or 4GB whichever is lesser.
217      */
218     temp = MIN(dram_end, 4096 * MiB);
219     fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
220 
221     fdt_pack(fdt);
222     /* copy in the device tree */
223     qemu_fdt_dumpdtb(fdt, fdtsize);
224 
225     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
226                           &address_space_memory);
227 
228     return fdt_addr;
229 }
230 
231 void riscv_rom_copy_firmware_info(hwaddr rom_base, hwaddr rom_size,
232                               uint32_t reset_vec_size, uint64_t kernel_entry)
233 {
234     struct fw_dynamic_info dinfo;
235     size_t dinfo_len;
236 
237     dinfo.magic = fw_dynamic_info_data(FW_DYNAMIC_INFO_MAGIC_VALUE);
238     dinfo.version = fw_dynamic_info_data(FW_DYNAMIC_INFO_VERSION);
239     dinfo.next_mode = fw_dynamic_info_data(FW_DYNAMIC_INFO_NEXT_MODE_S);
240     dinfo.next_addr = fw_dynamic_info_data(kernel_entry);
241     dinfo.options = 0;
242     dinfo.boot_hart = 0;
243     dinfo_len = sizeof(dinfo);
244 
245     /**
246      * copy the dynamic firmware info. This information is specific to
247      * OpenSBI but doesn't break any other firmware as long as they don't
248      * expect any certain value in "a2" register.
249      */
250     if (dinfo_len > (rom_size - reset_vec_size)) {
251         error_report("not enough space to store dynamic firmware info");
252         exit(1);
253     }
254 
255     rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
256                            rom_base + reset_vec_size,
257                            &address_space_memory);
258 }
259 
260 void riscv_setup_rom_reset_vec(hwaddr start_addr, hwaddr rom_base,
261                                hwaddr rom_size, uint64_t kernel_entry,
262                                uint32_t fdt_load_addr, void *fdt)
263 {
264     int i;
265     uint32_t start_addr_hi32 = 0x00000000;
266 
267     #if defined(TARGET_RISCV64)
268     start_addr_hi32 = start_addr >> 32;
269     #endif
270     /* reset vector */
271     uint32_t reset_vec[10] = {
272         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
273         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
274         0xf1402573,                  /*     csrr   a0, mhartid  */
275 #if defined(TARGET_RISCV32)
276         0x0202a583,                  /*     lw     a1, 32(t0) */
277         0x0182a283,                  /*     lw     t0, 24(t0) */
278 #elif defined(TARGET_RISCV64)
279         0x0202b583,                  /*     ld     a1, 32(t0) */
280         0x0182b283,                  /*     ld     t0, 24(t0) */
281 #endif
282         0x00028067,                  /*     jr     t0 */
283         start_addr,                  /* start: .dword */
284         start_addr_hi32,
285         fdt_load_addr,               /* fdt_laddr: .dword */
286         0x00000000,
287                                      /* fw_dyn: */
288     };
289 
290     /* copy in the reset vector in little_endian byte order */
291     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
292         reset_vec[i] = cpu_to_le32(reset_vec[i]);
293     }
294     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
295                           rom_base, &address_space_memory);
296     riscv_rom_copy_firmware_info(rom_base, rom_size, sizeof(reset_vec),
297                                  kernel_entry);
298 
299     return;
300 }
301