xref: /openbmc/qemu/hw/riscv/boot.c (revision 9bc9e95119445d7a430b0fc8b7daf22a3612bbd3)
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          return firmware_end;
163      }
164  
165      firmware_size = load_image_targphys_as(firmware_filename,
166                                             firmware_load_addr,
167                                             current_machine->ram_size, NULL);
168  
169      if (firmware_size > 0) {
170          return firmware_load_addr + firmware_size;
171      }
172  
173      error_report("could not load firmware '%s'", firmware_filename);
174      exit(1);
175  }
176  
177  static void riscv_load_initrd(MachineState *machine, uint64_t kernel_entry)
178  {
179      const char *filename = machine->initrd_filename;
180      uint64_t mem_size = machine->ram_size;
181      void *fdt = machine->fdt;
182      hwaddr start, end;
183      ssize_t size;
184  
185      g_assert(filename != NULL);
186  
187      /*
188       * We want to put the initrd far enough into RAM that when the
189       * kernel is uncompressed it will not clobber the initrd. However
190       * on boards without much RAM we must ensure that we still leave
191       * enough room for a decent sized initrd, and on boards with large
192       * amounts of RAM, we put the initrd at 512MB to allow large kernels
193       * to boot.
194       * So for boards with less than 1GB of RAM we put the initrd
195       * halfway into RAM, and for boards with 1GB of RAM or more we put
196       * the initrd at 512MB.
197       */
198      start = kernel_entry + MIN(mem_size / 2, 512 * MiB);
199  
200      size = load_ramdisk(filename, start, mem_size - start);
201      if (size == -1) {
202          size = load_image_targphys(filename, start, mem_size - start);
203          if (size == -1) {
204              error_report("could not load ramdisk '%s'", filename);
205              exit(1);
206          }
207      }
208  
209      /* Some RISC-V machines (e.g. opentitan) don't have a fdt. */
210      if (fdt) {
211          end = start + size;
212          qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-start", start);
213          qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-end", end);
214      }
215  }
216  
217  target_ulong riscv_load_kernel(MachineState *machine,
218                                 RISCVHartArrayState *harts,
219                                 target_ulong kernel_start_addr,
220                                 bool load_initrd,
221                                 symbol_fn_t sym_cb)
222  {
223      const char *kernel_filename = machine->kernel_filename;
224      uint64_t kernel_load_base, kernel_entry;
225      void *fdt = machine->fdt;
226  
227      g_assert(kernel_filename != NULL);
228  
229      /*
230       * NB: Use low address not ELF entry point to ensure that the fw_dynamic
231       * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
232       * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
233       * the (expected) load address load address. This allows kernels to have
234       * separate SBI and ELF entry points (used by FreeBSD, for example).
235       */
236      if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
237                           NULL, &kernel_load_base, NULL, NULL, 0,
238                           EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
239          kernel_entry = kernel_load_base;
240          goto out;
241      }
242  
243      if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
244                         NULL, NULL, NULL) > 0) {
245          goto out;
246      }
247  
248      if (load_image_targphys_as(kernel_filename, kernel_start_addr,
249                                 current_machine->ram_size, NULL) > 0) {
250          kernel_entry = kernel_start_addr;
251          goto out;
252      }
253  
254      error_report("could not load kernel '%s'", kernel_filename);
255      exit(1);
256  
257  out:
258      /*
259       * For 32 bit CPUs 'kernel_entry' can be sign-extended by
260       * load_elf_ram_sym().
261       */
262      if (riscv_is_32bit(harts)) {
263          kernel_entry = extract64(kernel_entry, 0, 32);
264      }
265  
266      if (load_initrd && machine->initrd_filename) {
267          riscv_load_initrd(machine, kernel_entry);
268      }
269  
270      if (fdt && machine->kernel_cmdline && *machine->kernel_cmdline) {
271          qemu_fdt_setprop_string(fdt, "/chosen", "bootargs",
272                                  machine->kernel_cmdline);
273      }
274  
275      return kernel_entry;
276  }
277  
278  /*
279   * This function makes an assumption that the DRAM interval
280   * 'dram_base' + 'dram_size' is contiguous.
281   *
282   * Considering that 'dram_end' is the lowest value between
283   * the end of the DRAM block and MachineState->ram_size, the
284   * FDT location will vary according to 'dram_base':
285   *
286   * - if 'dram_base' is less that 3072 MiB, the FDT will be
287   * put at the lowest value between 3072 MiB and 'dram_end';
288   *
289   * - if 'dram_base' is higher than 3072 MiB, the FDT will be
290   * put at 'dram_end'.
291   *
292   * The FDT is fdt_packed() during the calculation.
293   */
294  uint64_t riscv_compute_fdt_addr(hwaddr dram_base, hwaddr dram_size,
295                                  MachineState *ms)
296  {
297      int ret = fdt_pack(ms->fdt);
298      hwaddr dram_end, temp;
299      int fdtsize;
300  
301      /* Should only fail if we've built a corrupted tree */
302      g_assert(ret == 0);
303  
304      fdtsize = fdt_totalsize(ms->fdt);
305      if (fdtsize <= 0) {
306          error_report("invalid device-tree");
307          exit(1);
308      }
309  
310      /*
311       * A dram_size == 0, usually from a MemMapEntry[].size element,
312       * means that the DRAM block goes all the way to ms->ram_size.
313       */
314      dram_end = dram_base;
315      dram_end += dram_size ? MIN(ms->ram_size, dram_size) : ms->ram_size;
316  
317      /*
318       * We should put fdt as far as possible to avoid kernel/initrd overwriting
319       * its content. But it should be addressable by 32 bit system as well.
320       * Thus, put it at an 2MB aligned address that less than fdt size from the
321       * end of dram or 3GB whichever is lesser.
322       */
323      temp = (dram_base < 3072 * MiB) ? MIN(dram_end, 3072 * MiB) : dram_end;
324  
325      return QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
326  }
327  
328  /*
329   * 'fdt_addr' is received as hwaddr because boards might put
330   * the FDT beyond 32-bit addressing boundary.
331   */
332  void riscv_load_fdt(hwaddr fdt_addr, void *fdt)
333  {
334      uint32_t fdtsize = fdt_totalsize(fdt);
335  
336      /* copy in the device tree */
337      qemu_fdt_dumpdtb(fdt, fdtsize);
338  
339      rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
340                            &address_space_memory);
341      qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
342                          rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
343  }
344  
345  void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
346                                    hwaddr rom_size, uint32_t reset_vec_size,
347                                    uint64_t kernel_entry)
348  {
349      struct fw_dynamic_info dinfo;
350      size_t dinfo_len;
351  
352      if (sizeof(dinfo.magic) == 4) {
353          dinfo.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
354          dinfo.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
355          dinfo.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
356          dinfo.next_addr = cpu_to_le32(kernel_entry);
357      } else {
358          dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
359          dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
360          dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
361          dinfo.next_addr = cpu_to_le64(kernel_entry);
362      }
363      dinfo.options = 0;
364      dinfo.boot_hart = 0;
365      dinfo_len = sizeof(dinfo);
366  
367      /**
368       * copy the dynamic firmware info. This information is specific to
369       * OpenSBI but doesn't break any other firmware as long as they don't
370       * expect any certain value in "a2" register.
371       */
372      if (dinfo_len > (rom_size - reset_vec_size)) {
373          error_report("not enough space to store dynamic firmware info");
374          exit(1);
375      }
376  
377      rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
378                             rom_base + reset_vec_size,
379                             &address_space_memory);
380  }
381  
382  void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
383                                 hwaddr start_addr,
384                                 hwaddr rom_base, hwaddr rom_size,
385                                 uint64_t kernel_entry,
386                                 uint64_t fdt_load_addr)
387  {
388      int i;
389      uint32_t start_addr_hi32 = 0x00000000;
390      uint32_t fdt_load_addr_hi32 = 0x00000000;
391  
392      if (!riscv_is_32bit(harts)) {
393          start_addr_hi32 = start_addr >> 32;
394          fdt_load_addr_hi32 = fdt_load_addr >> 32;
395      }
396      /* reset vector */
397      uint32_t reset_vec[10] = {
398          0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
399          0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
400          0xf1402573,                  /*     csrr   a0, mhartid  */
401          0,
402          0,
403          0x00028067,                  /*     jr     t0 */
404          start_addr,                  /* start: .dword */
405          start_addr_hi32,
406          fdt_load_addr,               /* fdt_laddr: .dword */
407          fdt_load_addr_hi32,
408                                       /* fw_dyn: */
409      };
410      if (riscv_is_32bit(harts)) {
411          reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
412          reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
413      } else {
414          reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
415          reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
416      }
417  
418      if (!harts->harts[0].cfg.ext_zicsr) {
419          /*
420           * The Zicsr extension has been disabled, so let's ensure we don't
421           * run the CSR instruction. Let's fill the address with a non
422           * compressed nop.
423           */
424          reset_vec[2] = 0x00000013;   /*     addi   x0, x0, 0 */
425      }
426  
427      /* copy in the reset vector in little_endian byte order */
428      for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
429          reset_vec[i] = cpu_to_le32(reset_vec[i]);
430      }
431      rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
432                            rom_base, &address_space_memory);
433      riscv_rom_copy_firmware_info(machine, rom_base, rom_size, sizeof(reset_vec),
434                                   kernel_entry);
435  }
436  
437  void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr)
438  {
439      CPUState *cs;
440  
441      for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
442          RISCVCPU *riscv_cpu = RISCV_CPU(cs);
443          riscv_cpu->env.kernel_addr = kernel_addr;
444          riscv_cpu->env.fdt_addr = fdt_addr;
445      }
446  }
447  
448  void riscv_setup_firmware_boot(MachineState *machine)
449  {
450      if (machine->kernel_filename) {
451          FWCfgState *fw_cfg;
452          fw_cfg = fw_cfg_find();
453  
454          assert(fw_cfg);
455          /*
456           * Expose the kernel, the command line, and the initrd in fw_cfg.
457           * We don't process them here at all, it's all left to the
458           * firmware.
459           */
460          load_image_to_fw_cfg(fw_cfg,
461                               FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA,
462                               machine->kernel_filename,
463                               true);
464          load_image_to_fw_cfg(fw_cfg,
465                               FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA,
466                               machine->initrd_filename, false);
467  
468          if (machine->kernel_cmdline) {
469              fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
470                             strlen(machine->kernel_cmdline) + 1);
471              fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA,
472                                machine->kernel_cmdline);
473          }
474      }
475  }
476