xref: /openbmc/qemu/hw/riscv/boot.c (revision ca5aa28e)
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     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(&harts->harts[0]);
40     return mcc->misa_mxl_max == MXL_RV32;
41 }
42 
43 /*
44  * Return the per-socket PLIC hart topology configuration string
45  * (caller must free with g_free())
46  */
47 char *riscv_plic_hart_config_string(int hart_count)
48 {
49     g_autofree const char **vals = g_new(const char *, hart_count + 1);
50     int i;
51 
52     for (i = 0; i < hart_count; i++) {
53         CPUState *cs = qemu_get_cpu(i);
54         CPURISCVState *env = &RISCV_CPU(cs)->env;
55 
56         if (kvm_enabled()) {
57             vals[i] = "S";
58         } else if (riscv_has_ext(env, RVS)) {
59             vals[i] = "MS";
60         } else {
61             vals[i] = "M";
62         }
63     }
64     vals[i] = NULL;
65 
66     /* g_strjoinv() obliges us to cast away const here */
67     return g_strjoinv(",", (char **)vals);
68 }
69 
70 target_ulong riscv_calc_kernel_start_addr(RISCVHartArrayState *harts,
71                                           target_ulong firmware_end_addr) {
72     if (riscv_is_32bit(harts)) {
73         return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
74     } else {
75         return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
76     }
77 }
78 
79 const char *riscv_default_firmware_name(RISCVHartArrayState *harts)
80 {
81     if (riscv_is_32bit(harts)) {
82         return RISCV32_BIOS_BIN;
83     }
84 
85     return RISCV64_BIOS_BIN;
86 }
87 
88 static char *riscv_find_bios(const char *bios_filename)
89 {
90     char *filename;
91 
92     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_filename);
93     if (filename == NULL) {
94         if (!qtest_enabled()) {
95             /*
96              * We only ship OpenSBI binary bios images in the QEMU source.
97              * For machines that use images other than the default bios,
98              * running QEMU test will complain hence let's suppress the error
99              * report for QEMU testing.
100              */
101             error_report("Unable to find the RISC-V BIOS \"%s\"",
102                          bios_filename);
103             exit(1);
104         }
105     }
106 
107     return filename;
108 }
109 
110 char *riscv_find_firmware(const char *firmware_filename,
111                           const char *default_machine_firmware)
112 {
113     char *filename = NULL;
114 
115     if ((!firmware_filename) || (!strcmp(firmware_filename, "default"))) {
116         /*
117          * The user didn't specify -bios, or has specified "-bios default".
118          * That means we are going to load the OpenSBI binary included in
119          * the QEMU source.
120          */
121         filename = riscv_find_bios(default_machine_firmware);
122     } else if (strcmp(firmware_filename, "none")) {
123         filename = riscv_find_bios(firmware_filename);
124     }
125 
126     return filename;
127 }
128 
129 target_ulong riscv_find_and_load_firmware(MachineState *machine,
130                                           const char *default_machine_firmware,
131                                           hwaddr *firmware_load_addr,
132                                           symbol_fn_t sym_cb)
133 {
134     char *firmware_filename;
135     target_ulong firmware_end_addr = *firmware_load_addr;
136 
137     firmware_filename = riscv_find_firmware(machine->firmware,
138                                             default_machine_firmware);
139 
140     if (firmware_filename) {
141         /* If not "none" load the firmware */
142         firmware_end_addr = riscv_load_firmware(firmware_filename,
143                                                 firmware_load_addr, sym_cb);
144         g_free(firmware_filename);
145     }
146 
147     return firmware_end_addr;
148 }
149 
150 target_ulong riscv_load_firmware(const char *firmware_filename,
151                                  hwaddr *firmware_load_addr,
152                                  symbol_fn_t sym_cb)
153 {
154     uint64_t firmware_entry, firmware_end;
155     ssize_t firmware_size;
156 
157     g_assert(firmware_filename != NULL);
158 
159     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
160                          &firmware_entry, NULL, &firmware_end, NULL,
161                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
162         *firmware_load_addr = firmware_entry;
163         return firmware_end;
164     }
165 
166     firmware_size = load_image_targphys_as(firmware_filename,
167                                            *firmware_load_addr,
168                                            current_machine->ram_size, NULL);
169 
170     if (firmware_size > 0) {
171         return *firmware_load_addr + firmware_size;
172     }
173 
174     error_report("could not load firmware '%s'", firmware_filename);
175     exit(1);
176 }
177 
178 static void riscv_load_initrd(MachineState *machine, uint64_t kernel_entry)
179 {
180     const char *filename = machine->initrd_filename;
181     uint64_t mem_size = machine->ram_size;
182     void *fdt = machine->fdt;
183     hwaddr start, end;
184     ssize_t size;
185 
186     g_assert(filename != NULL);
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 put the initrd at 512MB to allow large kernels
194      * to boot.
195      * So for boards with less than 1GB of RAM we put the initrd
196      * halfway into RAM, and for boards with 1GB of RAM or more we put
197      * the initrd at 512MB.
198      */
199     start = kernel_entry + MIN(mem_size / 2, 512 * 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     /* Some RISC-V machines (e.g. opentitan) don't have a fdt. */
211     if (fdt) {
212         end = start + size;
213         qemu_fdt_setprop_u64(fdt, "/chosen", "linux,initrd-start", start);
214         qemu_fdt_setprop_u64(fdt, "/chosen", "linux,initrd-end", end);
215     }
216 }
217 
218 target_ulong riscv_load_kernel(MachineState *machine,
219                                RISCVHartArrayState *harts,
220                                target_ulong kernel_start_addr,
221                                bool load_initrd,
222                                symbol_fn_t sym_cb)
223 {
224     const char *kernel_filename = machine->kernel_filename;
225     uint64_t kernel_load_base, kernel_entry;
226     void *fdt = machine->fdt;
227 
228     g_assert(kernel_filename != NULL);
229 
230     /*
231      * NB: Use low address not ELF entry point to ensure that the fw_dynamic
232      * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
233      * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
234      * the (expected) load address load address. This allows kernels to have
235      * separate SBI and ELF entry points (used by FreeBSD, for example).
236      */
237     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
238                          NULL, &kernel_load_base, NULL, NULL, 0,
239                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
240         kernel_entry = kernel_load_base;
241         goto out;
242     }
243 
244     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
245                        NULL, NULL, NULL) > 0) {
246         goto out;
247     }
248 
249     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
250                                current_machine->ram_size, NULL) > 0) {
251         kernel_entry = kernel_start_addr;
252         goto out;
253     }
254 
255     error_report("could not load kernel '%s'", kernel_filename);
256     exit(1);
257 
258 out:
259     /*
260      * For 32 bit CPUs 'kernel_entry' can be sign-extended by
261      * load_elf_ram_sym().
262      */
263     if (riscv_is_32bit(harts)) {
264         kernel_entry = extract64(kernel_entry, 0, 32);
265     }
266 
267     if (load_initrd && machine->initrd_filename) {
268         riscv_load_initrd(machine, kernel_entry);
269     }
270 
271     if (fdt && machine->kernel_cmdline && *machine->kernel_cmdline) {
272         qemu_fdt_setprop_string(fdt, "/chosen", "bootargs",
273                                 machine->kernel_cmdline);
274     }
275 
276     return kernel_entry;
277 }
278 
279 /*
280  * This function makes an assumption that the DRAM interval
281  * 'dram_base' + 'dram_size' is contiguous.
282  *
283  * Considering that 'dram_end' is the lowest value between
284  * the end of the DRAM block and MachineState->ram_size, the
285  * FDT location will vary according to 'dram_base':
286  *
287  * - if 'dram_base' is less that 3072 MiB, the FDT will be
288  * put at the lowest value between 3072 MiB and 'dram_end';
289  *
290  * - if 'dram_base' is higher than 3072 MiB, the FDT will be
291  * put at 'dram_end'.
292  *
293  * The FDT is fdt_packed() during the calculation.
294  */
295 uint64_t riscv_compute_fdt_addr(hwaddr dram_base, hwaddr dram_size,
296                                 MachineState *ms)
297 {
298     int ret = fdt_pack(ms->fdt);
299     hwaddr dram_end, temp;
300     int fdtsize;
301 
302     /* Should only fail if we've built a corrupted tree */
303     g_assert(ret == 0);
304 
305     fdtsize = fdt_totalsize(ms->fdt);
306     if (fdtsize <= 0) {
307         error_report("invalid device-tree");
308         exit(1);
309     }
310 
311     /*
312      * A dram_size == 0, usually from a MemMapEntry[].size element,
313      * means that the DRAM block goes all the way to ms->ram_size.
314      */
315     dram_end = dram_base;
316     dram_end += dram_size ? MIN(ms->ram_size, dram_size) : ms->ram_size;
317 
318     /*
319      * We should put fdt as far as possible to avoid kernel/initrd overwriting
320      * its content. But it should be addressable by 32 bit system as well.
321      * Thus, put it at an 2MB aligned address that less than fdt size from the
322      * end of dram or 3GB whichever is lesser.
323      */
324     temp = (dram_base < 3072 * MiB) ? MIN(dram_end, 3072 * MiB) : dram_end;
325 
326     return QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
327 }
328 
329 /*
330  * 'fdt_addr' is received as hwaddr because boards might put
331  * the FDT beyond 32-bit addressing boundary.
332  */
333 void riscv_load_fdt(hwaddr fdt_addr, void *fdt)
334 {
335     uint32_t fdtsize = fdt_totalsize(fdt);
336 
337     /* copy in the device tree */
338     qemu_fdt_dumpdtb(fdt, fdtsize);
339 
340     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
341                           &address_space_memory);
342     qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
343                         rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
344 }
345 
346 void riscv_rom_copy_firmware_info(MachineState *machine,
347                                   RISCVHartArrayState *harts,
348                                   hwaddr rom_base, hwaddr rom_size,
349                                   uint32_t reset_vec_size,
350                                   uint64_t kernel_entry)
351 {
352     struct fw_dynamic_info32 dinfo32;
353     struct fw_dynamic_info dinfo;
354     size_t dinfo_len;
355 
356     if (riscv_is_32bit(harts)) {
357         dinfo32.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
358         dinfo32.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
359         dinfo32.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
360         dinfo32.next_addr = cpu_to_le32(kernel_entry);
361         dinfo32.options = 0;
362         dinfo32.boot_hart = 0;
363         dinfo_len = sizeof(dinfo32);
364     } else {
365         dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
366         dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
367         dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
368         dinfo.next_addr = cpu_to_le64(kernel_entry);
369         dinfo.options = 0;
370         dinfo.boot_hart = 0;
371         dinfo_len = sizeof(dinfo);
372     }
373 
374     /**
375      * copy the dynamic firmware info. This information is specific to
376      * OpenSBI but doesn't break any other firmware as long as they don't
377      * expect any certain value in "a2" register.
378      */
379     if (dinfo_len > (rom_size - reset_vec_size)) {
380         error_report("not enough space to store dynamic firmware info");
381         exit(1);
382     }
383 
384     rom_add_blob_fixed_as("mrom.finfo",
385                            riscv_is_32bit(harts) ?
386                            (void *)&dinfo32 : (void *)&dinfo,
387                            dinfo_len,
388                            rom_base + reset_vec_size,
389                            &address_space_memory);
390 }
391 
392 void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
393                                hwaddr start_addr,
394                                hwaddr rom_base, hwaddr rom_size,
395                                uint64_t kernel_entry,
396                                uint64_t fdt_load_addr)
397 {
398     int i;
399     uint32_t start_addr_hi32 = 0x00000000;
400     uint32_t fdt_load_addr_hi32 = 0x00000000;
401 
402     if (!riscv_is_32bit(harts)) {
403         start_addr_hi32 = start_addr >> 32;
404         fdt_load_addr_hi32 = fdt_load_addr >> 32;
405     }
406     /* reset vector */
407     uint32_t reset_vec[10] = {
408         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
409         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
410         0xf1402573,                  /*     csrr   a0, mhartid  */
411         0,
412         0,
413         0x00028067,                  /*     jr     t0 */
414         start_addr,                  /* start: .dword */
415         start_addr_hi32,
416         fdt_load_addr,               /* fdt_laddr: .dword */
417         fdt_load_addr_hi32,
418                                      /* fw_dyn: */
419     };
420     if (riscv_is_32bit(harts)) {
421         reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
422         reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
423     } else {
424         reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
425         reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
426     }
427 
428     if (!harts->harts[0].cfg.ext_zicsr) {
429         /*
430          * The Zicsr extension has been disabled, so let's ensure we don't
431          * run the CSR instruction. Let's fill the address with a non
432          * compressed nop.
433          */
434         reset_vec[2] = 0x00000013;   /*     addi   x0, x0, 0 */
435     }
436 
437     /* copy in the reset vector in little_endian byte order */
438     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
439         reset_vec[i] = cpu_to_le32(reset_vec[i]);
440     }
441     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
442                           rom_base, &address_space_memory);
443     riscv_rom_copy_firmware_info(machine, harts,
444                                  rom_base, rom_size,
445                                  sizeof(reset_vec),
446                                  kernel_entry);
447 }
448 
449 void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr)
450 {
451     CPUState *cs;
452 
453     for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
454         RISCVCPU *riscv_cpu = RISCV_CPU(cs);
455         riscv_cpu->env.kernel_addr = kernel_addr;
456         riscv_cpu->env.fdt_addr = fdt_addr;
457     }
458 }
459 
460 void riscv_setup_firmware_boot(MachineState *machine)
461 {
462     if (machine->kernel_filename) {
463         FWCfgState *fw_cfg;
464         fw_cfg = fw_cfg_find();
465 
466         assert(fw_cfg);
467         /*
468          * Expose the kernel, the command line, and the initrd in fw_cfg.
469          * We don't process them here at all, it's all left to the
470          * firmware.
471          */
472         load_image_to_fw_cfg(fw_cfg,
473                              FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA,
474                              machine->kernel_filename,
475                              true);
476         load_image_to_fw_cfg(fw_cfg,
477                              FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA,
478                              machine->initrd_filename, false);
479 
480         if (machine->kernel_cmdline) {
481             fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
482                            strlen(machine->kernel_cmdline) + 1);
483             fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA,
484                               machine->kernel_cmdline);
485         }
486     }
487 }
488