xref: /openbmc/qemu/hw/riscv/boot.c (revision d3592955af2a015be1d7138643b4a010eee0ff0c)
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 void riscv_boot_info_init(RISCVBootInfo *info, RISCVHartArrayState *harts)
71 {
72     info->kernel_size = 0;
73     info->is_32bit = riscv_is_32bit(harts);
74 }
75 
76 target_ulong riscv_calc_kernel_start_addr(RISCVBootInfo *info,
77                                           target_ulong firmware_end_addr) {
78     if (info->is_32bit) {
79         return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
80     } else {
81         return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
82     }
83 }
84 
85 const char *riscv_default_firmware_name(RISCVHartArrayState *harts)
86 {
87     if (riscv_is_32bit(harts)) {
88         return RISCV32_BIOS_BIN;
89     }
90 
91     return RISCV64_BIOS_BIN;
92 }
93 
94 static char *riscv_find_bios(const char *bios_filename)
95 {
96     char *filename;
97 
98     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_filename);
99     if (filename == NULL) {
100         if (!qtest_enabled()) {
101             /*
102              * We only ship OpenSBI binary bios images in the QEMU source.
103              * For machines that use images other than the default bios,
104              * running QEMU test will complain hence let's suppress the error
105              * report for QEMU testing.
106              */
107             error_report("Unable to find the RISC-V BIOS \"%s\"",
108                          bios_filename);
109             exit(1);
110         }
111     }
112 
113     return filename;
114 }
115 
116 char *riscv_find_firmware(const char *firmware_filename,
117                           const char *default_machine_firmware)
118 {
119     char *filename = NULL;
120 
121     if ((!firmware_filename) || (!strcmp(firmware_filename, "default"))) {
122         /*
123          * The user didn't specify -bios, or has specified "-bios default".
124          * That means we are going to load the OpenSBI binary included in
125          * the QEMU source.
126          */
127         filename = riscv_find_bios(default_machine_firmware);
128     } else if (strcmp(firmware_filename, "none")) {
129         filename = riscv_find_bios(firmware_filename);
130     }
131 
132     return filename;
133 }
134 
135 target_ulong riscv_find_and_load_firmware(MachineState *machine,
136                                           const char *default_machine_firmware,
137                                           hwaddr *firmware_load_addr,
138                                           symbol_fn_t sym_cb)
139 {
140     char *firmware_filename;
141     target_ulong firmware_end_addr = *firmware_load_addr;
142 
143     firmware_filename = riscv_find_firmware(machine->firmware,
144                                             default_machine_firmware);
145 
146     if (firmware_filename) {
147         /* If not "none" load the firmware */
148         firmware_end_addr = riscv_load_firmware(firmware_filename,
149                                                 firmware_load_addr, sym_cb);
150         g_free(firmware_filename);
151     }
152 
153     return firmware_end_addr;
154 }
155 
156 target_ulong riscv_load_firmware(const char *firmware_filename,
157                                  hwaddr *firmware_load_addr,
158                                  symbol_fn_t sym_cb)
159 {
160     uint64_t firmware_entry, firmware_end;
161     ssize_t firmware_size;
162 
163     g_assert(firmware_filename != NULL);
164 
165     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
166                          &firmware_entry, NULL, &firmware_end, NULL,
167                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
168         *firmware_load_addr = firmware_entry;
169         return firmware_end;
170     }
171 
172     firmware_size = load_image_targphys_as(firmware_filename,
173                                            *firmware_load_addr,
174                                            current_machine->ram_size, NULL);
175 
176     if (firmware_size > 0) {
177         return *firmware_load_addr + firmware_size;
178     }
179 
180     error_report("could not load firmware '%s'", firmware_filename);
181     exit(1);
182 }
183 
184 static void riscv_load_initrd(MachineState *machine, RISCVBootInfo *info)
185 {
186     const char *filename = machine->initrd_filename;
187     uint64_t mem_size = machine->ram_size;
188     void *fdt = machine->fdt;
189     hwaddr start, end;
190     ssize_t size;
191 
192     g_assert(filename != NULL);
193 
194     /*
195      * We want to put the initrd far enough into RAM that when the
196      * kernel is uncompressed it will not clobber the initrd. However
197      * on boards without much RAM we must ensure that we still leave
198      * enough room for a decent sized initrd, and on boards with large
199      * amounts of RAM, we put the initrd at 512MB to allow large kernels
200      * to boot.
201      * So for boards with less than 1GB of RAM we put the initrd
202      * halfway into RAM, and for boards with 1GB of RAM or more we put
203      * the initrd at 512MB.
204      */
205     start = info->image_low_addr + MIN(mem_size / 2, 512 * MiB);
206 
207     size = load_ramdisk(filename, start, mem_size - start);
208     if (size == -1) {
209         size = load_image_targphys(filename, start, mem_size - start);
210         if (size == -1) {
211             error_report("could not load ramdisk '%s'", filename);
212             exit(1);
213         }
214     }
215 
216     /* Some RISC-V machines (e.g. opentitan) don't have a fdt. */
217     if (fdt) {
218         end = start + size;
219         qemu_fdt_setprop_u64(fdt, "/chosen", "linux,initrd-start", start);
220         qemu_fdt_setprop_u64(fdt, "/chosen", "linux,initrd-end", end);
221     }
222 }
223 
224 void riscv_load_kernel(MachineState *machine,
225                        RISCVBootInfo *info,
226                        target_ulong kernel_start_addr,
227                        bool load_initrd,
228                        symbol_fn_t sym_cb)
229 {
230     const char *kernel_filename = machine->kernel_filename;
231     ssize_t kernel_size;
232     void *fdt = machine->fdt;
233 
234     g_assert(kernel_filename != NULL);
235 
236     /*
237      * NB: Use low address not ELF entry point to ensure that the fw_dynamic
238      * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
239      * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
240      * the (expected) load address load address. This allows kernels to have
241      * separate SBI and ELF entry points (used by FreeBSD, for example).
242      */
243     kernel_size = load_elf_ram_sym(kernel_filename, NULL, NULL, NULL, NULL,
244                                    &info->image_low_addr, &info->image_high_addr,
245                                    NULL, 0, EM_RISCV, 1, 0, NULL, true, sym_cb);
246     if (kernel_size > 0) {
247         info->kernel_size = kernel_size;
248         goto out;
249     }
250 
251     kernel_size = load_uimage_as(kernel_filename, &info->image_low_addr,
252                                  NULL, NULL, NULL, NULL, NULL);
253     if (kernel_size > 0) {
254         info->kernel_size = kernel_size;
255         info->image_high_addr = info->image_low_addr + kernel_size;
256         goto out;
257     }
258 
259     kernel_size = load_image_targphys_as(kernel_filename, kernel_start_addr,
260                                          current_machine->ram_size, NULL);
261     if (kernel_size > 0) {
262         info->kernel_size = kernel_size;
263         info->image_low_addr = kernel_start_addr;
264         info->image_high_addr = info->image_low_addr + kernel_size;
265         goto out;
266     }
267 
268     error_report("could not load kernel '%s'", kernel_filename);
269     exit(1);
270 
271 out:
272     /*
273      * For 32 bit CPUs 'image_low_addr' can be sign-extended by
274      * load_elf_ram_sym().
275      */
276     if (info->is_32bit) {
277         info->image_low_addr = extract64(info->image_low_addr, 0, 32);
278     }
279 
280     if (load_initrd && machine->initrd_filename) {
281         riscv_load_initrd(machine, info);
282     }
283 
284     if (fdt && machine->kernel_cmdline && *machine->kernel_cmdline) {
285         qemu_fdt_setprop_string(fdt, "/chosen", "bootargs",
286                                 machine->kernel_cmdline);
287     }
288 }
289 
290 /*
291  * This function makes an assumption that the DRAM interval
292  * 'dram_base' + 'dram_size' is contiguous.
293  *
294  * Considering that 'dram_end' is the lowest value between
295  * the end of the DRAM block and MachineState->ram_size, the
296  * FDT location will vary according to 'dram_base':
297  *
298  * - if 'dram_base' is less that 3072 MiB, the FDT will be
299  * put at the lowest value between 3072 MiB and 'dram_end';
300  *
301  * - if 'dram_base' is higher than 3072 MiB, the FDT will be
302  * put at 'dram_end'.
303  *
304  * The FDT is fdt_packed() during the calculation.
305  */
306 uint64_t riscv_compute_fdt_addr(hwaddr dram_base, hwaddr dram_size,
307                                 MachineState *ms, RISCVBootInfo *info)
308 {
309     int ret = fdt_pack(ms->fdt);
310     hwaddr dram_end, temp;
311     int fdtsize;
312 
313     /* Should only fail if we've built a corrupted tree */
314     g_assert(ret == 0);
315 
316     fdtsize = fdt_totalsize(ms->fdt);
317     if (fdtsize <= 0) {
318         error_report("invalid device-tree");
319         exit(1);
320     }
321 
322     /*
323      * A dram_size == 0, usually from a MemMapEntry[].size element,
324      * means that the DRAM block goes all the way to ms->ram_size.
325      */
326     dram_end = dram_base;
327     dram_end += dram_size ? MIN(ms->ram_size, dram_size) : ms->ram_size;
328 
329     /*
330      * We should put fdt as far as possible to avoid kernel/initrd overwriting
331      * its content. But it should be addressable by 32 bit system as well in RV32.
332      * Thus, put it near to the end of dram in RV64, and put it near to the end
333      * of dram or 3GB whichever is lesser in RV32.
334      */
335     if (!info->is_32bit) {
336         temp = dram_end;
337     } else {
338         temp = (dram_base < 3072 * MiB) ? MIN(dram_end, 3072 * MiB) : dram_end;
339     }
340 
341     return QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
342 }
343 
344 /*
345  * 'fdt_addr' is received as hwaddr because boards might put
346  * the FDT beyond 32-bit addressing boundary.
347  */
348 void riscv_load_fdt(hwaddr fdt_addr, void *fdt)
349 {
350     uint32_t fdtsize = fdt_totalsize(fdt);
351 
352     /* copy in the device tree */
353     qemu_fdt_dumpdtb(fdt, fdtsize);
354 
355     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
356                           &address_space_memory);
357     qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
358                         rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
359 }
360 
361 void riscv_rom_copy_firmware_info(MachineState *machine,
362                                   RISCVHartArrayState *harts,
363                                   hwaddr rom_base, hwaddr rom_size,
364                                   uint32_t reset_vec_size,
365                                   uint64_t kernel_entry)
366 {
367     struct fw_dynamic_info32 dinfo32;
368     struct fw_dynamic_info dinfo;
369     size_t dinfo_len;
370 
371     if (riscv_is_32bit(harts)) {
372         dinfo32.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
373         dinfo32.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
374         dinfo32.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
375         dinfo32.next_addr = cpu_to_le32(kernel_entry);
376         dinfo32.options = 0;
377         dinfo32.boot_hart = 0;
378         dinfo_len = sizeof(dinfo32);
379     } else {
380         dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
381         dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
382         dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
383         dinfo.next_addr = cpu_to_le64(kernel_entry);
384         dinfo.options = 0;
385         dinfo.boot_hart = 0;
386         dinfo_len = sizeof(dinfo);
387     }
388 
389     /**
390      * copy the dynamic firmware info. This information is specific to
391      * OpenSBI but doesn't break any other firmware as long as they don't
392      * expect any certain value in "a2" register.
393      */
394     if (dinfo_len > (rom_size - reset_vec_size)) {
395         error_report("not enough space to store dynamic firmware info");
396         exit(1);
397     }
398 
399     rom_add_blob_fixed_as("mrom.finfo",
400                            riscv_is_32bit(harts) ?
401                            (void *)&dinfo32 : (void *)&dinfo,
402                            dinfo_len,
403                            rom_base + reset_vec_size,
404                            &address_space_memory);
405 }
406 
407 void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
408                                hwaddr start_addr,
409                                hwaddr rom_base, hwaddr rom_size,
410                                uint64_t kernel_entry,
411                                uint64_t fdt_load_addr)
412 {
413     int i;
414     uint32_t start_addr_hi32 = 0x00000000;
415     uint32_t fdt_load_addr_hi32 = 0x00000000;
416 
417     if (!riscv_is_32bit(harts)) {
418         start_addr_hi32 = start_addr >> 32;
419         fdt_load_addr_hi32 = fdt_load_addr >> 32;
420     }
421     /* reset vector */
422     uint32_t reset_vec[10] = {
423         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
424         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
425         0xf1402573,                  /*     csrr   a0, mhartid  */
426         0,
427         0,
428         0x00028067,                  /*     jr     t0 */
429         start_addr,                  /* start: .dword */
430         start_addr_hi32,
431         fdt_load_addr,               /* fdt_laddr: .dword */
432         fdt_load_addr_hi32,
433                                      /* fw_dyn: */
434     };
435     if (riscv_is_32bit(harts)) {
436         reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
437         reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
438     } else {
439         reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
440         reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
441     }
442 
443     if (!harts->harts[0].cfg.ext_zicsr) {
444         /*
445          * The Zicsr extension has been disabled, so let's ensure we don't
446          * run the CSR instruction. Let's fill the address with a non
447          * compressed nop.
448          */
449         reset_vec[2] = 0x00000013;   /*     addi   x0, x0, 0 */
450     }
451 
452     /* copy in the reset vector in little_endian byte order */
453     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
454         reset_vec[i] = cpu_to_le32(reset_vec[i]);
455     }
456     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
457                           rom_base, &address_space_memory);
458     riscv_rom_copy_firmware_info(machine, harts,
459                                  rom_base, rom_size,
460                                  sizeof(reset_vec),
461                                  kernel_entry);
462 }
463 
464 void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr)
465 {
466     CPUState *cs;
467 
468     for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
469         RISCVCPU *riscv_cpu = RISCV_CPU(cs);
470         riscv_cpu->env.kernel_addr = kernel_addr;
471         riscv_cpu->env.fdt_addr = fdt_addr;
472     }
473 }
474 
475 void riscv_setup_firmware_boot(MachineState *machine)
476 {
477     if (machine->kernel_filename) {
478         FWCfgState *fw_cfg;
479         fw_cfg = fw_cfg_find();
480 
481         assert(fw_cfg);
482         /*
483          * Expose the kernel, the command line, and the initrd in fw_cfg.
484          * We don't process them here at all, it's all left to the
485          * firmware.
486          */
487         load_image_to_fw_cfg(fw_cfg,
488                              FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA,
489                              machine->kernel_filename,
490                              true);
491         load_image_to_fw_cfg(fw_cfg,
492                              FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA,
493                              machine->initrd_filename, false);
494 
495         if (machine->kernel_cmdline) {
496             fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
497                            strlen(machine->kernel_cmdline) + 1);
498             fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA,
499                               machine->kernel_cmdline);
500         }
501     }
502 }
503