xref: /openbmc/qemu/hw/riscv/boot.c (revision 9d3f7108bc43e93ceef7faa27c87eea8295c33ed)
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 #include "sysemu/reset.h"
34 
35 #include <libfdt.h>
36 
37 bool riscv_is_32bit(RISCVHartArrayState *harts)
38 {
39     return harts->harts[0].env.misa_mxl_max == MXL_RV32;
40 }
41 
42 /*
43  * Return the per-socket PLIC hart topology configuration string
44  * (caller must free with g_free())
45  */
46 char *riscv_plic_hart_config_string(int hart_count)
47 {
48     g_autofree const char **vals = g_new(const char *, hart_count + 1);
49     int i;
50 
51     for (i = 0; i < hart_count; i++) {
52         CPUState *cs = qemu_get_cpu(i);
53         CPURISCVState *env = &RISCV_CPU(cs)->env;
54 
55         if (kvm_enabled()) {
56             vals[i] = "S";
57         } else if (riscv_has_ext(env, RVS)) {
58             vals[i] = "MS";
59         } else {
60             vals[i] = "M";
61         }
62     }
63     vals[i] = NULL;
64 
65     /* g_strjoinv() obliges us to cast away const here */
66     return g_strjoinv(",", (char **)vals);
67 }
68 
69 target_ulong riscv_calc_kernel_start_addr(RISCVHartArrayState *harts,
70                                           target_ulong firmware_end_addr) {
71     if (riscv_is_32bit(harts)) {
72         return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
73     } else {
74         return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
75     }
76 }
77 
78 const char *riscv_default_firmware_name(RISCVHartArrayState *harts)
79 {
80     if (riscv_is_32bit(harts)) {
81         return RISCV32_BIOS_BIN;
82     }
83 
84     return RISCV64_BIOS_BIN;
85 }
86 
87 static char *riscv_find_firmware(const char *firmware_filename)
88 {
89     char *filename;
90 
91     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware_filename);
92     if (filename == NULL) {
93         if (!qtest_enabled()) {
94             /*
95              * We only ship OpenSBI binary bios images in the QEMU source.
96              * For machines that use images other than the default bios,
97              * running QEMU test will complain hence let's suppress the error
98              * report for QEMU testing.
99              */
100             error_report("Unable to load the RISC-V firmware \"%s\"",
101                          firmware_filename);
102             exit(1);
103         }
104     }
105 
106     return filename;
107 }
108 
109 target_ulong riscv_find_and_load_firmware(MachineState *machine,
110                                           const char *default_machine_firmware,
111                                           hwaddr firmware_load_addr,
112                                           symbol_fn_t sym_cb)
113 {
114     char *firmware_filename = NULL;
115     target_ulong firmware_end_addr = firmware_load_addr;
116 
117     if ((!machine->firmware) || (!strcmp(machine->firmware, "default"))) {
118         /*
119          * The user didn't specify -bios, or has specified "-bios default".
120          * That means we are going to load the OpenSBI binary included in
121          * the QEMU source.
122          */
123         firmware_filename = riscv_find_firmware(default_machine_firmware);
124     } else if (strcmp(machine->firmware, "none")) {
125         firmware_filename = riscv_find_firmware(machine->firmware);
126     }
127 
128     if (firmware_filename) {
129         /* If not "none" load the firmware */
130         firmware_end_addr = riscv_load_firmware(firmware_filename,
131                                                 firmware_load_addr, sym_cb);
132         g_free(firmware_filename);
133     }
134 
135     return firmware_end_addr;
136 }
137 
138 target_ulong riscv_load_firmware(const char *firmware_filename,
139                                  hwaddr firmware_load_addr,
140                                  symbol_fn_t sym_cb)
141 {
142     uint64_t firmware_entry, firmware_end;
143     ssize_t firmware_size;
144 
145     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
146                          &firmware_entry, NULL, &firmware_end, NULL,
147                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
148         return firmware_end;
149     }
150 
151     firmware_size = load_image_targphys_as(firmware_filename,
152                                            firmware_load_addr,
153                                            current_machine->ram_size, NULL);
154 
155     if (firmware_size > 0) {
156         return firmware_load_addr + firmware_size;
157     }
158 
159     error_report("could not load firmware '%s'", firmware_filename);
160     exit(1);
161 }
162 
163 target_ulong riscv_load_kernel(const char *kernel_filename,
164                                target_ulong kernel_start_addr,
165                                symbol_fn_t sym_cb)
166 {
167     uint64_t kernel_load_base, kernel_entry;
168 
169     /*
170      * NB: Use low address not ELF entry point to ensure that the fw_dynamic
171      * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
172      * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
173      * the (expected) load address load address. This allows kernels to have
174      * separate SBI and ELF entry points (used by FreeBSD, for example).
175      */
176     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
177                          NULL, &kernel_load_base, NULL, NULL, 0,
178                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
179         return kernel_load_base;
180     }
181 
182     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
183                        NULL, NULL, NULL) > 0) {
184         return kernel_entry;
185     }
186 
187     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
188                                current_machine->ram_size, NULL) > 0) {
189         return kernel_start_addr;
190     }
191 
192     error_report("could not load kernel '%s'", kernel_filename);
193     exit(1);
194 }
195 
196 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
197                          uint64_t kernel_entry, hwaddr *start)
198 {
199     ssize_t size;
200 
201     /*
202      * We want to put the initrd far enough into RAM that when the
203      * kernel is uncompressed it will not clobber the initrd. However
204      * on boards without much RAM we must ensure that we still leave
205      * enough room for a decent sized initrd, and on boards with large
206      * amounts of RAM we must avoid the initrd being so far up in RAM
207      * that it is outside lowmem and inaccessible to the kernel.
208      * So for boards with less  than 256MB of RAM we put the initrd
209      * halfway into RAM, and for boards with 256MB of RAM or more we put
210      * the initrd at 128MB.
211      */
212     *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
213 
214     size = load_ramdisk(filename, *start, mem_size - *start);
215     if (size == -1) {
216         size = load_image_targphys(filename, *start, mem_size - *start);
217         if (size == -1) {
218             error_report("could not load ramdisk '%s'", filename);
219             exit(1);
220         }
221     }
222 
223     return *start + size;
224 }
225 
226 uint64_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
227 {
228     uint64_t temp, fdt_addr;
229     hwaddr dram_end = dram_base + mem_size;
230     int ret, fdtsize = fdt_totalsize(fdt);
231 
232     if (fdtsize <= 0) {
233         error_report("invalid device-tree");
234         exit(1);
235     }
236 
237     /*
238      * We should put fdt as far as possible to avoid kernel/initrd overwriting
239      * its content. But it should be addressable by 32 bit system as well.
240      * Thus, put it at an 2MB aligned address that less than fdt size from the
241      * end of dram or 3GB whichever is lesser.
242      */
243     temp = (dram_base < 3072 * MiB) ? MIN(dram_end, 3072 * MiB) : dram_end;
244     fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
245 
246     ret = fdt_pack(fdt);
247     /* Should only fail if we've built a corrupted tree */
248     g_assert(ret == 0);
249     /* copy in the device tree */
250     qemu_fdt_dumpdtb(fdt, fdtsize);
251 
252     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
253                           &address_space_memory);
254     qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
255                         rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
256 
257     return fdt_addr;
258 }
259 
260 void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
261                                   hwaddr rom_size, uint32_t reset_vec_size,
262                                   uint64_t kernel_entry)
263 {
264     struct fw_dynamic_info dinfo;
265     size_t dinfo_len;
266 
267     if (sizeof(dinfo.magic) == 4) {
268         dinfo.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
269         dinfo.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
270         dinfo.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
271         dinfo.next_addr = cpu_to_le32(kernel_entry);
272     } else {
273         dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
274         dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
275         dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
276         dinfo.next_addr = cpu_to_le64(kernel_entry);
277     }
278     dinfo.options = 0;
279     dinfo.boot_hart = 0;
280     dinfo_len = sizeof(dinfo);
281 
282     /**
283      * copy the dynamic firmware info. This information is specific to
284      * OpenSBI but doesn't break any other firmware as long as they don't
285      * expect any certain value in "a2" register.
286      */
287     if (dinfo_len > (rom_size - reset_vec_size)) {
288         error_report("not enough space to store dynamic firmware info");
289         exit(1);
290     }
291 
292     rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
293                            rom_base + reset_vec_size,
294                            &address_space_memory);
295 }
296 
297 void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
298                                hwaddr start_addr,
299                                hwaddr rom_base, hwaddr rom_size,
300                                uint64_t kernel_entry,
301                                uint64_t fdt_load_addr)
302 {
303     int i;
304     uint32_t start_addr_hi32 = 0x00000000;
305     uint32_t fdt_load_addr_hi32 = 0x00000000;
306 
307     if (!riscv_is_32bit(harts)) {
308         start_addr_hi32 = start_addr >> 32;
309         fdt_load_addr_hi32 = fdt_load_addr >> 32;
310     }
311     /* reset vector */
312     uint32_t reset_vec[10] = {
313         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
314         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
315         0xf1402573,                  /*     csrr   a0, mhartid  */
316         0,
317         0,
318         0x00028067,                  /*     jr     t0 */
319         start_addr,                  /* start: .dword */
320         start_addr_hi32,
321         fdt_load_addr,               /* fdt_laddr: .dword */
322         fdt_load_addr_hi32,
323                                      /* fw_dyn: */
324     };
325     if (riscv_is_32bit(harts)) {
326         reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
327         reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
328     } else {
329         reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
330         reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
331     }
332 
333     /* copy in the reset vector in little_endian byte order */
334     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
335         reset_vec[i] = cpu_to_le32(reset_vec[i]);
336     }
337     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
338                           rom_base, &address_space_memory);
339     riscv_rom_copy_firmware_info(machine, rom_base, rom_size, sizeof(reset_vec),
340                                  kernel_entry);
341 }
342 
343 void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr)
344 {
345     CPUState *cs;
346 
347     for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
348         RISCVCPU *riscv_cpu = RISCV_CPU(cs);
349         riscv_cpu->env.kernel_addr = kernel_addr;
350         riscv_cpu->env.fdt_addr = fdt_addr;
351     }
352 }
353 
354 void riscv_setup_firmware_boot(MachineState *machine)
355 {
356     if (machine->kernel_filename) {
357         FWCfgState *fw_cfg;
358         fw_cfg = fw_cfg_find();
359 
360         assert(fw_cfg);
361         /*
362          * Expose the kernel, the command line, and the initrd in fw_cfg.
363          * We don't process them here at all, it's all left to the
364          * firmware.
365          */
366         load_image_to_fw_cfg(fw_cfg,
367                              FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA,
368                              machine->kernel_filename,
369                              true);
370         load_image_to_fw_cfg(fw_cfg,
371                              FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA,
372                              machine->initrd_filename, false);
373 
374         if (machine->kernel_cmdline) {
375             fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
376                            strlen(machine->kernel_cmdline) + 1);
377             fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA,
378                               machine->kernel_cmdline);
379         }
380     }
381 }
382