xref: /openbmc/qemu/hw/riscv/boot.c (revision 8c6631e6)
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_bios(const char *bios_filename)
88 {
89     char *filename;
90 
91     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_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 find the RISC-V BIOS \"%s\"",
101                          bios_filename);
102             exit(1);
103         }
104     }
105 
106     return filename;
107 }
108 
109 char *riscv_find_firmware(const char *firmware_filename,
110                           const char *default_machine_firmware)
111 {
112     char *filename = NULL;
113 
114     if ((!firmware_filename) || (!strcmp(firmware_filename, "default"))) {
115         /*
116          * The user didn't specify -bios, or has specified "-bios default".
117          * That means we are going to load the OpenSBI binary included in
118          * the QEMU source.
119          */
120         filename = riscv_find_bios(default_machine_firmware);
121     } else if (strcmp(firmware_filename, "none")) {
122         filename = riscv_find_bios(firmware_filename);
123     }
124 
125     return filename;
126 }
127 
128 target_ulong riscv_find_and_load_firmware(MachineState *machine,
129                                           const char *default_machine_firmware,
130                                           hwaddr firmware_load_addr,
131                                           symbol_fn_t sym_cb)
132 {
133     char *firmware_filename;
134     target_ulong firmware_end_addr = firmware_load_addr;
135 
136     firmware_filename = riscv_find_firmware(machine->firmware,
137                                             default_machine_firmware);
138 
139     if (firmware_filename) {
140         /* If not "none" load the firmware */
141         firmware_end_addr = riscv_load_firmware(firmware_filename,
142                                                 firmware_load_addr, sym_cb);
143         g_free(firmware_filename);
144     }
145 
146     return firmware_end_addr;
147 }
148 
149 target_ulong riscv_load_firmware(const char *firmware_filename,
150                                  hwaddr firmware_load_addr,
151                                  symbol_fn_t sym_cb)
152 {
153     uint64_t firmware_entry, firmware_end;
154     ssize_t firmware_size;
155 
156     g_assert(firmware_filename != NULL);
157 
158     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
159                          &firmware_entry, NULL, &firmware_end, NULL,
160                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
161         return firmware_end;
162     }
163 
164     firmware_size = load_image_targphys_as(firmware_filename,
165                                            firmware_load_addr,
166                                            current_machine->ram_size, NULL);
167 
168     if (firmware_size > 0) {
169         return firmware_load_addr + firmware_size;
170     }
171 
172     error_report("could not load firmware '%s'", firmware_filename);
173     exit(1);
174 }
175 
176 target_ulong riscv_load_kernel(MachineState *machine,
177                                target_ulong kernel_start_addr,
178                                symbol_fn_t sym_cb)
179 {
180     const char *kernel_filename = machine->kernel_filename;
181     uint64_t kernel_load_base, kernel_entry;
182 
183     g_assert(kernel_filename != NULL);
184 
185     /*
186      * NB: Use low address not ELF entry point to ensure that the fw_dynamic
187      * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
188      * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
189      * the (expected) load address load address. This allows kernels to have
190      * separate SBI and ELF entry points (used by FreeBSD, for example).
191      */
192     if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
193                          NULL, &kernel_load_base, NULL, NULL, 0,
194                          EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
195         return kernel_load_base;
196     }
197 
198     if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
199                        NULL, NULL, NULL) > 0) {
200         return kernel_entry;
201     }
202 
203     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
204                                current_machine->ram_size, NULL) > 0) {
205         return kernel_start_addr;
206     }
207 
208     error_report("could not load kernel '%s'", kernel_filename);
209     exit(1);
210 }
211 
212 void riscv_load_initrd(MachineState *machine, uint64_t kernel_entry)
213 {
214     const char *filename = machine->initrd_filename;
215     uint64_t mem_size = machine->ram_size;
216     void *fdt = machine->fdt;
217     hwaddr start, end;
218     ssize_t size;
219 
220     g_assert(filename != NULL);
221 
222     /*
223      * We want to put the initrd far enough into RAM that when the
224      * kernel is uncompressed it will not clobber the initrd. However
225      * on boards without much RAM we must ensure that we still leave
226      * enough room for a decent sized initrd, and on boards with large
227      * amounts of RAM we must avoid the initrd being so far up in RAM
228      * that it is outside lowmem and inaccessible to the kernel.
229      * So for boards with less  than 256MB of RAM we put the initrd
230      * halfway into RAM, and for boards with 256MB of RAM or more we put
231      * the initrd at 128MB.
232      */
233     start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
234 
235     size = load_ramdisk(filename, start, mem_size - start);
236     if (size == -1) {
237         size = load_image_targphys(filename, start, mem_size - start);
238         if (size == -1) {
239             error_report("could not load ramdisk '%s'", filename);
240             exit(1);
241         }
242     }
243 
244     /* Some RISC-V machines (e.g. opentitan) don't have a fdt. */
245     if (fdt) {
246         end = start + size;
247         qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-start", start);
248         qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-end", end);
249     }
250 }
251 
252 /*
253  * This function makes an assumption that the DRAM interval
254  * 'dram_base' + 'dram_size' is contiguous.
255  *
256  * Considering that 'dram_end' is the lowest value between
257  * the end of the DRAM block and MachineState->ram_size, the
258  * FDT location will vary according to 'dram_base':
259  *
260  * - if 'dram_base' is less that 3072 MiB, the FDT will be
261  * put at the lowest value between 3072 MiB and 'dram_end';
262  *
263  * - if 'dram_base' is higher than 3072 MiB, the FDT will be
264  * put at 'dram_end'.
265  *
266  * The FDT is fdt_packed() during the calculation.
267  */
268 uint64_t riscv_compute_fdt_addr(hwaddr dram_base, hwaddr dram_size,
269                                 MachineState *ms)
270 {
271     int ret = fdt_pack(ms->fdt);
272     hwaddr dram_end, temp;
273     int fdtsize;
274 
275     /* Should only fail if we've built a corrupted tree */
276     g_assert(ret == 0);
277 
278     fdtsize = fdt_totalsize(ms->fdt);
279     if (fdtsize <= 0) {
280         error_report("invalid device-tree");
281         exit(1);
282     }
283 
284     /*
285      * A dram_size == 0, usually from a MemMapEntry[].size element,
286      * means that the DRAM block goes all the way to ms->ram_size.
287      */
288     dram_end = dram_base;
289     dram_end += dram_size ? MIN(ms->ram_size, dram_size) : ms->ram_size;
290 
291     /*
292      * We should put fdt as far as possible to avoid kernel/initrd overwriting
293      * its content. But it should be addressable by 32 bit system as well.
294      * Thus, put it at an 2MB aligned address that less than fdt size from the
295      * end of dram or 3GB whichever is lesser.
296      */
297     temp = (dram_base < 3072 * MiB) ? MIN(dram_end, 3072 * MiB) : dram_end;
298 
299     return QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
300 }
301 
302 /*
303  * 'fdt_addr' is received as hwaddr because boards might put
304  * the FDT beyond 32-bit addressing boundary.
305  */
306 void riscv_load_fdt(hwaddr fdt_addr, void *fdt)
307 {
308     uint32_t fdtsize = fdt_totalsize(fdt);
309 
310     /* copy in the device tree */
311     qemu_fdt_dumpdtb(fdt, fdtsize);
312 
313     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
314                           &address_space_memory);
315     qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
316                         rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
317 }
318 
319 void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
320                                   hwaddr rom_size, uint32_t reset_vec_size,
321                                   uint64_t kernel_entry)
322 {
323     struct fw_dynamic_info dinfo;
324     size_t dinfo_len;
325 
326     if (sizeof(dinfo.magic) == 4) {
327         dinfo.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
328         dinfo.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
329         dinfo.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
330         dinfo.next_addr = cpu_to_le32(kernel_entry);
331     } else {
332         dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
333         dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
334         dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
335         dinfo.next_addr = cpu_to_le64(kernel_entry);
336     }
337     dinfo.options = 0;
338     dinfo.boot_hart = 0;
339     dinfo_len = sizeof(dinfo);
340 
341     /**
342      * copy the dynamic firmware info. This information is specific to
343      * OpenSBI but doesn't break any other firmware as long as they don't
344      * expect any certain value in "a2" register.
345      */
346     if (dinfo_len > (rom_size - reset_vec_size)) {
347         error_report("not enough space to store dynamic firmware info");
348         exit(1);
349     }
350 
351     rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
352                            rom_base + reset_vec_size,
353                            &address_space_memory);
354 }
355 
356 void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
357                                hwaddr start_addr,
358                                hwaddr rom_base, hwaddr rom_size,
359                                uint64_t kernel_entry,
360                                uint64_t fdt_load_addr)
361 {
362     int i;
363     uint32_t start_addr_hi32 = 0x00000000;
364     uint32_t fdt_load_addr_hi32 = 0x00000000;
365 
366     if (!riscv_is_32bit(harts)) {
367         start_addr_hi32 = start_addr >> 32;
368         fdt_load_addr_hi32 = fdt_load_addr >> 32;
369     }
370     /* reset vector */
371     uint32_t reset_vec[10] = {
372         0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
373         0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
374         0xf1402573,                  /*     csrr   a0, mhartid  */
375         0,
376         0,
377         0x00028067,                  /*     jr     t0 */
378         start_addr,                  /* start: .dword */
379         start_addr_hi32,
380         fdt_load_addr,               /* fdt_laddr: .dword */
381         fdt_load_addr_hi32,
382                                      /* fw_dyn: */
383     };
384     if (riscv_is_32bit(harts)) {
385         reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
386         reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
387     } else {
388         reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
389         reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
390     }
391 
392     if (!harts->harts[0].cfg.ext_icsr) {
393         /*
394          * The Zicsr extension has been disabled, so let's ensure we don't
395          * run the CSR instruction. Let's fill the address with a non
396          * compressed nop.
397          */
398         reset_vec[2] = 0x00000013;   /*     addi   x0, x0, 0 */
399     }
400 
401     /* copy in the reset vector in little_endian byte order */
402     for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
403         reset_vec[i] = cpu_to_le32(reset_vec[i]);
404     }
405     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
406                           rom_base, &address_space_memory);
407     riscv_rom_copy_firmware_info(machine, rom_base, rom_size, sizeof(reset_vec),
408                                  kernel_entry);
409 }
410 
411 void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr)
412 {
413     CPUState *cs;
414 
415     for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
416         RISCVCPU *riscv_cpu = RISCV_CPU(cs);
417         riscv_cpu->env.kernel_addr = kernel_addr;
418         riscv_cpu->env.fdt_addr = fdt_addr;
419     }
420 }
421 
422 void riscv_setup_firmware_boot(MachineState *machine)
423 {
424     if (machine->kernel_filename) {
425         FWCfgState *fw_cfg;
426         fw_cfg = fw_cfg_find();
427 
428         assert(fw_cfg);
429         /*
430          * Expose the kernel, the command line, and the initrd in fw_cfg.
431          * We don't process them here at all, it's all left to the
432          * firmware.
433          */
434         load_image_to_fw_cfg(fw_cfg,
435                              FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA,
436                              machine->kernel_filename,
437                              true);
438         load_image_to_fw_cfg(fw_cfg,
439                              FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA,
440                              machine->initrd_filename, false);
441 
442         if (machine->kernel_cmdline) {
443             fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
444                            strlen(machine->kernel_cmdline) + 1);
445             fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA,
446                               machine->kernel_cmdline);
447         }
448     }
449 }
450