xref: /openbmc/qemu/hw/riscv/boot.c (revision 0fbb5d2d)
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_32bit(RISCVHartArrayState *harts)
37 {
38     return harts->harts[0].env.misa_mxl_max == MXL_RV32;
39 }
40 
41 /*
42  * Return the per-socket PLIC hart topology configuration string
43  * (caller must free with g_free())
44  */
45 char *riscv_plic_hart_config_string(int hart_count)
46 {
47     g_autofree const char **vals = g_new(const char *, hart_count + 1);
48     int i;
49 
50     for (i = 0; i < hart_count; i++) {
51         CPUState *cs = qemu_get_cpu(i);
52         CPURISCVState *env = &RISCV_CPU(cs)->env;
53 
54         if (riscv_has_ext(env, RVS)) {
55             vals[i] = "MS";
56         } else {
57             vals[i] = "M";
58         }
59     }
60     vals[i] = NULL;
61 
62     /* g_strjoinv() obliges us to cast away const here */
63     return g_strjoinv(",", (char **)vals);
64 }
65 
66 target_ulong riscv_calc_kernel_start_addr(RISCVHartArrayState *harts,
67                                           target_ulong firmware_end_addr) {
68     if (riscv_is_32bit(harts)) {
69         return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
70     } else {
71         return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
72     }
73 }
74 
75 target_ulong riscv_find_and_load_firmware(MachineState *machine,
76                                           const char *default_machine_firmware,
77                                           hwaddr firmware_load_addr,
78                                           symbol_fn_t sym_cb)
79 {
80     char *firmware_filename = NULL;
81     target_ulong firmware_end_addr = firmware_load_addr;
82 
83     if ((!machine->firmware) || (!strcmp(machine->firmware, "default"))) {
84         /*
85          * The user didn't specify -bios, or has specified "-bios default".
86          * That means we are going to load the OpenSBI binary included in
87          * the QEMU source.
88          */
89         firmware_filename = riscv_find_firmware(default_machine_firmware);
90     } else if (strcmp(machine->firmware, "none")) {
91         firmware_filename = riscv_find_firmware(machine->firmware);
92     }
93 
94     if (firmware_filename) {
95         /* If not "none" load the firmware */
96         firmware_end_addr = riscv_load_firmware(firmware_filename,
97                                                 firmware_load_addr, sym_cb);
98         g_free(firmware_filename);
99     }
100 
101     return firmware_end_addr;
102 }
103 
104 char *riscv_find_firmware(const char *firmware_filename)
105 {
106     char *filename;
107 
108     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware_filename);
109     if (filename == NULL) {
110         if (!qtest_enabled()) {
111             /*
112              * We only ship plain binary bios images in the QEMU source.
113              * With Spike machine that uses ELF images as the default bios,
114              * running QEMU test will complain hence let's suppress the error
115              * report for QEMU testing.
116              */
117             error_report("Unable to load the RISC-V firmware \"%s\"",
118                          firmware_filename);
119             exit(1);
120         }
121     }
122 
123     return filename;
124 }
125 
126 target_ulong riscv_load_firmware(const char *firmware_filename,
127                                  hwaddr firmware_load_addr,
128                                  symbol_fn_t sym_cb)
129 {
130     uint64_t firmware_entry, firmware_size, firmware_end;
131 
132     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
133                          &firmware_entry, NULL, &firmware_end, NULL,
134                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
135         return firmware_end;
136     }
137 
138     firmware_size = load_image_targphys_as(firmware_filename,
139                                            firmware_load_addr,
140                                            current_machine->ram_size, NULL);
141 
142     if (firmware_size > 0) {
143         return firmware_load_addr + firmware_size;
144     }
145 
146     error_report("could not load firmware '%s'", firmware_filename);
147     exit(1);
148 }
149 
150 target_ulong riscv_load_kernel(const char *kernel_filename,
151                                target_ulong kernel_start_addr,
152                                symbol_fn_t sym_cb)
153 {
154     uint64_t kernel_load_base, kernel_entry;
155 
156     /*
157      * NB: Use low address not ELF entry point to ensure that the fw_dynamic
158      * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
159      * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
160      * the (expected) load address load address. This allows kernels to have
161      * separate SBI and ELF entry points (used by FreeBSD, for example).
162      */
163     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
164                          NULL, &kernel_load_base, NULL, NULL, 0,
165                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
166         return kernel_load_base;
167     }
168 
169     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
170                        NULL, NULL, NULL) > 0) {
171         return kernel_entry;
172     }
173 
174     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
175                                current_machine->ram_size, NULL) > 0) {
176         return kernel_start_addr;
177     }
178 
179     error_report("could not load kernel '%s'", kernel_filename);
180     exit(1);
181 }
182 
183 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
184                          uint64_t kernel_entry, hwaddr *start)
185 {
186     int size;
187 
188     /*
189      * We want to put the initrd far enough into RAM that when the
190      * kernel is uncompressed it will not clobber the initrd. However
191      * on boards without much RAM we must ensure that we still leave
192      * enough room for a decent sized initrd, and on boards with large
193      * amounts of RAM we must avoid the initrd being so far up in RAM
194      * that it is outside lowmem and inaccessible to the kernel.
195      * So for boards with less  than 256MB of RAM we put the initrd
196      * halfway into RAM, and for boards with 256MB of RAM or more we put
197      * the initrd at 128MB.
198      */
199     *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
200 
201     size = load_ramdisk(filename, *start, mem_size - *start);
202     if (size == -1) {
203         size = load_image_targphys(filename, *start, mem_size - *start);
204         if (size == -1) {
205             error_report("could not load ramdisk '%s'", filename);
206             exit(1);
207         }
208     }
209 
210     return *start + size;
211 }
212 
213 uint32_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
214 {
215     uint32_t temp, fdt_addr;
216     hwaddr dram_end = dram_base + mem_size;
217     int ret, fdtsize = fdt_totalsize(fdt);
218 
219     if (fdtsize <= 0) {
220         error_report("invalid device-tree");
221         exit(1);
222     }
223 
224     /*
225      * We should put fdt as far as possible to avoid kernel/initrd overwriting
226      * its content. But it should be addressable by 32 bit system as well.
227      * Thus, put it at an 16MB aligned address that less than fdt size from the
228      * end of dram or 3GB whichever is lesser.
229      */
230     temp = MIN(dram_end, 3072 * MiB);
231     fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 16 * MiB);
232 
233     ret = fdt_pack(fdt);
234     /* Should only fail if we've built a corrupted tree */
235     g_assert(ret == 0);
236     /* copy in the device tree */
237     qemu_fdt_dumpdtb(fdt, fdtsize);
238 
239     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
240                           &address_space_memory);
241 
242     return fdt_addr;
243 }
244 
245 void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
246                                   hwaddr rom_size, uint32_t reset_vec_size,
247                                   uint64_t kernel_entry)
248 {
249     struct fw_dynamic_info dinfo;
250     size_t dinfo_len;
251 
252     if (sizeof(dinfo.magic) == 4) {
253         dinfo.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
254         dinfo.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
255         dinfo.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
256         dinfo.next_addr = cpu_to_le32(kernel_entry);
257     } else {
258         dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
259         dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
260         dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
261         dinfo.next_addr = cpu_to_le64(kernel_entry);
262     }
263     dinfo.options = 0;
264     dinfo.boot_hart = 0;
265     dinfo_len = sizeof(dinfo);
266 
267     /**
268      * copy the dynamic firmware info. This information is specific to
269      * OpenSBI but doesn't break any other firmware as long as they don't
270      * expect any certain value in "a2" register.
271      */
272     if (dinfo_len > (rom_size - reset_vec_size)) {
273         error_report("not enough space to store dynamic firmware info");
274         exit(1);
275     }
276 
277     rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
278                            rom_base + reset_vec_size,
279                            &address_space_memory);
280 }
281 
282 void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
283                                hwaddr start_addr,
284                                hwaddr rom_base, hwaddr rom_size,
285                                uint64_t kernel_entry,
286                                uint32_t fdt_load_addr, void *fdt)
287 {
288     int i;
289     uint32_t start_addr_hi32 = 0x00000000;
290 
291     if (!riscv_is_32bit(harts)) {
292         start_addr_hi32 = start_addr >> 32;
293     }
294     /* reset vector */
295     uint32_t reset_vec[10] = {
296         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
297         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
298         0xf1402573,                  /*     csrr   a0, mhartid  */
299         0,
300         0,
301         0x00028067,                  /*     jr     t0 */
302         start_addr,                  /* start: .dword */
303         start_addr_hi32,
304         fdt_load_addr,               /* fdt_laddr: .dword */
305         0x00000000,
306                                      /* fw_dyn: */
307     };
308     if (riscv_is_32bit(harts)) {
309         reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
310         reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
311     } else {
312         reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
313         reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
314     }
315 
316     /* copy in the reset vector in little_endian byte order */
317     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
318         reset_vec[i] = cpu_to_le32(reset_vec[i]);
319     }
320     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
321                           rom_base, &address_space_memory);
322     riscv_rom_copy_firmware_info(machine, rom_base, rom_size, sizeof(reset_vec),
323                                  kernel_entry);
324 
325     return;
326 }
327