xref: /openbmc/qemu/hw/riscv/boot.c (revision 096b778f)
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/datadir.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 #include "sysemu/kvm.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 (kvm_enabled()) {
55             vals[i] = "S";
56         } else if (riscv_has_ext(env, RVS)) {
57             vals[i] = "MS";
58         } else {
59             vals[i] = "M";
60         }
61     }
62     vals[i] = NULL;
63 
64     /* g_strjoinv() obliges us to cast away const here */
65     return g_strjoinv(",", (char **)vals);
66 }
67 
68 target_ulong riscv_calc_kernel_start_addr(RISCVHartArrayState *harts,
69                                           target_ulong firmware_end_addr) {
70     if (riscv_is_32bit(harts)) {
71         return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
72     } else {
73         return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
74     }
75 }
76 
77 target_ulong riscv_find_and_load_firmware(MachineState *machine,
78                                           const char *default_machine_firmware,
79                                           hwaddr firmware_load_addr,
80                                           symbol_fn_t sym_cb)
81 {
82     char *firmware_filename = NULL;
83     target_ulong firmware_end_addr = firmware_load_addr;
84 
85     if ((!machine->firmware) || (!strcmp(machine->firmware, "default"))) {
86         /*
87          * The user didn't specify -bios, or has specified "-bios default".
88          * That means we are going to load the OpenSBI binary included in
89          * the QEMU source.
90          */
91         firmware_filename = riscv_find_firmware(default_machine_firmware);
92     } else if (strcmp(machine->firmware, "none")) {
93         firmware_filename = riscv_find_firmware(machine->firmware);
94     }
95 
96     if (firmware_filename) {
97         /* If not "none" load the firmware */
98         firmware_end_addr = riscv_load_firmware(firmware_filename,
99                                                 firmware_load_addr, sym_cb);
100         g_free(firmware_filename);
101     }
102 
103     return firmware_end_addr;
104 }
105 
106 char *riscv_find_firmware(const char *firmware_filename)
107 {
108     char *filename;
109 
110     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware_filename);
111     if (filename == NULL) {
112         if (!qtest_enabled()) {
113             /*
114              * We only ship plain binary bios images in the QEMU source.
115              * With Spike machine that uses ELF images as the default bios,
116              * running QEMU test will complain hence let's suppress the error
117              * report for QEMU testing.
118              */
119             error_report("Unable to load the RISC-V firmware \"%s\"",
120                          firmware_filename);
121             exit(1);
122         }
123     }
124 
125     return filename;
126 }
127 
128 target_ulong riscv_load_firmware(const char *firmware_filename,
129                                  hwaddr firmware_load_addr,
130                                  symbol_fn_t sym_cb)
131 {
132     uint64_t firmware_entry, firmware_size, firmware_end;
133 
134     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
135                          &firmware_entry, NULL, &firmware_end, NULL,
136                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
137         return firmware_end;
138     }
139 
140     firmware_size = load_image_targphys_as(firmware_filename,
141                                            firmware_load_addr,
142                                            current_machine->ram_size, NULL);
143 
144     if (firmware_size > 0) {
145         return firmware_load_addr + firmware_size;
146     }
147 
148     error_report("could not load firmware '%s'", firmware_filename);
149     exit(1);
150 }
151 
152 target_ulong riscv_load_kernel(const char *kernel_filename,
153                                target_ulong kernel_start_addr,
154                                symbol_fn_t sym_cb)
155 {
156     uint64_t kernel_load_base, kernel_entry;
157 
158     /*
159      * NB: Use low address not ELF entry point to ensure that the fw_dynamic
160      * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
161      * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
162      * the (expected) load address load address. This allows kernels to have
163      * separate SBI and ELF entry points (used by FreeBSD, for example).
164      */
165     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
166                          NULL, &kernel_load_base, NULL, NULL, 0,
167                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
168         return kernel_load_base;
169     }
170 
171     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
172                        NULL, NULL, NULL) > 0) {
173         return kernel_entry;
174     }
175 
176     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
177                                current_machine->ram_size, NULL) > 0) {
178         return kernel_start_addr;
179     }
180 
181     error_report("could not load kernel '%s'", kernel_filename);
182     exit(1);
183 }
184 
185 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
186                          uint64_t kernel_entry, hwaddr *start)
187 {
188     int size;
189 
190     /*
191      * We want to put the initrd far enough into RAM that when the
192      * kernel is uncompressed it will not clobber the initrd. However
193      * on boards without much RAM we must ensure that we still leave
194      * enough room for a decent sized initrd, and on boards with large
195      * amounts of RAM we must avoid the initrd being so far up in RAM
196      * that it is outside lowmem and inaccessible to the kernel.
197      * So for boards with less  than 256MB of RAM we put the initrd
198      * halfway into RAM, and for boards with 256MB of RAM or more we put
199      * the initrd at 128MB.
200      */
201     *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
202 
203     size = load_ramdisk(filename, *start, mem_size - *start);
204     if (size == -1) {
205         size = load_image_targphys(filename, *start, mem_size - *start);
206         if (size == -1) {
207             error_report("could not load ramdisk '%s'", filename);
208             exit(1);
209         }
210     }
211 
212     return *start + size;
213 }
214 
215 uint32_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
216 {
217     uint32_t temp, fdt_addr;
218     hwaddr dram_end = dram_base + mem_size;
219     int ret, fdtsize = fdt_totalsize(fdt);
220 
221     if (fdtsize <= 0) {
222         error_report("invalid device-tree");
223         exit(1);
224     }
225 
226     /*
227      * We should put fdt as far as possible to avoid kernel/initrd overwriting
228      * its content. But it should be addressable by 32 bit system as well.
229      * Thus, put it at an 16MB aligned address that less than fdt size from the
230      * end of dram or 3GB whichever is lesser.
231      */
232     temp = MIN(dram_end, 3072 * MiB);
233     fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 16 * MiB);
234 
235     ret = fdt_pack(fdt);
236     /* Should only fail if we've built a corrupted tree */
237     g_assert(ret == 0);
238     /* copy in the device tree */
239     qemu_fdt_dumpdtb(fdt, fdtsize);
240 
241     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
242                           &address_space_memory);
243 
244     return fdt_addr;
245 }
246 
247 void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
248                                   hwaddr rom_size, uint32_t reset_vec_size,
249                                   uint64_t kernel_entry)
250 {
251     struct fw_dynamic_info dinfo;
252     size_t dinfo_len;
253 
254     if (sizeof(dinfo.magic) == 4) {
255         dinfo.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
256         dinfo.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
257         dinfo.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
258         dinfo.next_addr = cpu_to_le32(kernel_entry);
259     } else {
260         dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
261         dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
262         dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
263         dinfo.next_addr = cpu_to_le64(kernel_entry);
264     }
265     dinfo.options = 0;
266     dinfo.boot_hart = 0;
267     dinfo_len = sizeof(dinfo);
268 
269     /**
270      * copy the dynamic firmware info. This information is specific to
271      * OpenSBI but doesn't break any other firmware as long as they don't
272      * expect any certain value in "a2" register.
273      */
274     if (dinfo_len > (rom_size - reset_vec_size)) {
275         error_report("not enough space to store dynamic firmware info");
276         exit(1);
277     }
278 
279     rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
280                            rom_base + reset_vec_size,
281                            &address_space_memory);
282 }
283 
284 void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
285                                hwaddr start_addr,
286                                hwaddr rom_base, hwaddr rom_size,
287                                uint64_t kernel_entry,
288                                uint32_t fdt_load_addr, void *fdt)
289 {
290     int i;
291     uint32_t start_addr_hi32 = 0x00000000;
292 
293     if (!riscv_is_32bit(harts)) {
294         start_addr_hi32 = start_addr >> 32;
295     }
296     /* reset vector */
297     uint32_t reset_vec[10] = {
298         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
299         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
300         0xf1402573,                  /*     csrr   a0, mhartid  */
301         0,
302         0,
303         0x00028067,                  /*     jr     t0 */
304         start_addr,                  /* start: .dword */
305         start_addr_hi32,
306         fdt_load_addr,               /* fdt_laddr: .dword */
307         0x00000000,
308                                      /* fw_dyn: */
309     };
310     if (riscv_is_32bit(harts)) {
311         reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
312         reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
313     } else {
314         reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
315         reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
316     }
317 
318     /* copy in the reset vector in little_endian byte order */
319     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
320         reset_vec[i] = cpu_to_le32(reset_vec[i]);
321     }
322     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
323                           rom_base, &address_space_memory);
324     riscv_rom_copy_firmware_info(machine, rom_base, rom_size, sizeof(reset_vec),
325                                  kernel_entry);
326 
327     return;
328 }
329 
330 void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr)
331 {
332     CPUState *cs;
333 
334     for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
335         RISCVCPU *riscv_cpu = RISCV_CPU(cs);
336         riscv_cpu->env.kernel_addr = kernel_addr;
337         riscv_cpu->env.fdt_addr = fdt_addr;
338     }
339 }
340