xref: /openbmc/qemu/hw/arm/boot.c (revision f1f7e4bf)
1 /*
2  * ARM kernel loader.
3  *
4  * Copyright (c) 2006-2007 CodeSourcery.
5  * Written by Paul Brook
6  *
7  * This code is licensed under the GPL.
8  */
9 
10 #include "config.h"
11 #include "hw/hw.h"
12 #include "hw/arm/arm.h"
13 #include "hw/arm/linux-boot-if.h"
14 #include "sysemu/kvm.h"
15 #include "sysemu/sysemu.h"
16 #include "hw/boards.h"
17 #include "hw/loader.h"
18 #include "elf.h"
19 #include "sysemu/device_tree.h"
20 #include "qemu/config-file.h"
21 #include "exec/address-spaces.h"
22 
23 /* Kernel boot protocol is specified in the kernel docs
24  * Documentation/arm/Booting and Documentation/arm64/booting.txt
25  * They have different preferred image load offsets from system RAM base.
26  */
27 #define KERNEL_ARGS_ADDR 0x100
28 #define KERNEL_LOAD_ADDR 0x00010000
29 #define KERNEL64_LOAD_ADDR 0x00080000
30 
31 typedef enum {
32     FIXUP_NONE = 0,     /* do nothing */
33     FIXUP_TERMINATOR,   /* end of insns */
34     FIXUP_BOARDID,      /* overwrite with board ID number */
35     FIXUP_BOARD_SETUP,  /* overwrite with board specific setup code address */
36     FIXUP_ARGPTR,       /* overwrite with pointer to kernel args */
37     FIXUP_ENTRYPOINT,   /* overwrite with kernel entry point */
38     FIXUP_GIC_CPU_IF,   /* overwrite with GIC CPU interface address */
39     FIXUP_BOOTREG,      /* overwrite with boot register address */
40     FIXUP_DSB,          /* overwrite with correct DSB insn for cpu */
41     FIXUP_MAX,
42 } FixupType;
43 
44 typedef struct ARMInsnFixup {
45     uint32_t insn;
46     FixupType fixup;
47 } ARMInsnFixup;
48 
49 static const ARMInsnFixup bootloader_aarch64[] = {
50     { 0x580000c0 }, /* ldr x0, arg ; Load the lower 32-bits of DTB */
51     { 0xaa1f03e1 }, /* mov x1, xzr */
52     { 0xaa1f03e2 }, /* mov x2, xzr */
53     { 0xaa1f03e3 }, /* mov x3, xzr */
54     { 0x58000084 }, /* ldr x4, entry ; Load the lower 32-bits of kernel entry */
55     { 0xd61f0080 }, /* br x4      ; Jump to the kernel entry point */
56     { 0, FIXUP_ARGPTR }, /* arg: .word @DTB Lower 32-bits */
57     { 0 }, /* .word @DTB Higher 32-bits */
58     { 0, FIXUP_ENTRYPOINT }, /* entry: .word @Kernel Entry Lower 32-bits */
59     { 0 }, /* .word @Kernel Entry Higher 32-bits */
60     { 0, FIXUP_TERMINATOR }
61 };
62 
63 /* A very small bootloader: call the board-setup code (if needed),
64  * set r0-r2, then jump to the kernel.
65  * If we're not calling boot setup code then we don't copy across
66  * the first BOOTLOADER_NO_BOARD_SETUP_OFFSET insns in this array.
67  */
68 
69 static const ARMInsnFixup bootloader[] = {
70     { 0xe28fe008 }, /* add     lr, pc, #8 */
71     { 0xe51ff004 }, /* ldr     pc, [pc, #-4] */
72     { 0, FIXUP_BOARD_SETUP },
73 #define BOOTLOADER_NO_BOARD_SETUP_OFFSET 3
74     { 0xe3a00000 }, /* mov     r0, #0 */
75     { 0xe59f1004 }, /* ldr     r1, [pc, #4] */
76     { 0xe59f2004 }, /* ldr     r2, [pc, #4] */
77     { 0xe59ff004 }, /* ldr     pc, [pc, #4] */
78     { 0, FIXUP_BOARDID },
79     { 0, FIXUP_ARGPTR },
80     { 0, FIXUP_ENTRYPOINT },
81     { 0, FIXUP_TERMINATOR }
82 };
83 
84 /* Handling for secondary CPU boot in a multicore system.
85  * Unlike the uniprocessor/primary CPU boot, this is platform
86  * dependent. The default code here is based on the secondary
87  * CPU boot protocol used on realview/vexpress boards, with
88  * some parameterisation to increase its flexibility.
89  * QEMU platform models for which this code is not appropriate
90  * should override write_secondary_boot and secondary_cpu_reset_hook
91  * instead.
92  *
93  * This code enables the interrupt controllers for the secondary
94  * CPUs and then puts all the secondary CPUs into a loop waiting
95  * for an interprocessor interrupt and polling a configurable
96  * location for the kernel secondary CPU entry point.
97  */
98 #define DSB_INSN 0xf57ff04f
99 #define CP15_DSB_INSN 0xee070f9a /* mcr cp15, 0, r0, c7, c10, 4 */
100 
101 static const ARMInsnFixup smpboot[] = {
102     { 0xe59f2028 }, /* ldr r2, gic_cpu_if */
103     { 0xe59f0028 }, /* ldr r0, bootreg_addr */
104     { 0xe3a01001 }, /* mov r1, #1 */
105     { 0xe5821000 }, /* str r1, [r2] - set GICC_CTLR.Enable */
106     { 0xe3a010ff }, /* mov r1, #0xff */
107     { 0xe5821004 }, /* str r1, [r2, 4] - set GIC_PMR.Priority to 0xff */
108     { 0, FIXUP_DSB },   /* dsb */
109     { 0xe320f003 }, /* wfi */
110     { 0xe5901000 }, /* ldr     r1, [r0] */
111     { 0xe1110001 }, /* tst     r1, r1 */
112     { 0x0afffffb }, /* beq     <wfi> */
113     { 0xe12fff11 }, /* bx      r1 */
114     { 0, FIXUP_GIC_CPU_IF }, /* gic_cpu_if: .word 0x.... */
115     { 0, FIXUP_BOOTREG }, /* bootreg_addr: .word 0x.... */
116     { 0, FIXUP_TERMINATOR }
117 };
118 
119 static void write_bootloader(const char *name, hwaddr addr,
120                              const ARMInsnFixup *insns, uint32_t *fixupcontext)
121 {
122     /* Fix up the specified bootloader fragment and write it into
123      * guest memory using rom_add_blob_fixed(). fixupcontext is
124      * an array giving the values to write in for the fixup types
125      * which write a value into the code array.
126      */
127     int i, len;
128     uint32_t *code;
129 
130     len = 0;
131     while (insns[len].fixup != FIXUP_TERMINATOR) {
132         len++;
133     }
134 
135     code = g_new0(uint32_t, len);
136 
137     for (i = 0; i < len; i++) {
138         uint32_t insn = insns[i].insn;
139         FixupType fixup = insns[i].fixup;
140 
141         switch (fixup) {
142         case FIXUP_NONE:
143             break;
144         case FIXUP_BOARDID:
145         case FIXUP_BOARD_SETUP:
146         case FIXUP_ARGPTR:
147         case FIXUP_ENTRYPOINT:
148         case FIXUP_GIC_CPU_IF:
149         case FIXUP_BOOTREG:
150         case FIXUP_DSB:
151             insn = fixupcontext[fixup];
152             break;
153         default:
154             abort();
155         }
156         code[i] = tswap32(insn);
157     }
158 
159     rom_add_blob_fixed(name, code, len * sizeof(uint32_t), addr);
160 
161     g_free(code);
162 }
163 
164 static void default_write_secondary(ARMCPU *cpu,
165                                     const struct arm_boot_info *info)
166 {
167     uint32_t fixupcontext[FIXUP_MAX];
168 
169     fixupcontext[FIXUP_GIC_CPU_IF] = info->gic_cpu_if_addr;
170     fixupcontext[FIXUP_BOOTREG] = info->smp_bootreg_addr;
171     if (arm_feature(&cpu->env, ARM_FEATURE_V7)) {
172         fixupcontext[FIXUP_DSB] = DSB_INSN;
173     } else {
174         fixupcontext[FIXUP_DSB] = CP15_DSB_INSN;
175     }
176 
177     write_bootloader("smpboot", info->smp_loader_start,
178                      smpboot, fixupcontext);
179 }
180 
181 static void default_reset_secondary(ARMCPU *cpu,
182                                     const struct arm_boot_info *info)
183 {
184     CPUState *cs = CPU(cpu);
185 
186     address_space_stl_notdirty(&address_space_memory, info->smp_bootreg_addr,
187                                0, MEMTXATTRS_UNSPECIFIED, NULL);
188     cpu_set_pc(cs, info->smp_loader_start);
189 }
190 
191 static inline bool have_dtb(const struct arm_boot_info *info)
192 {
193     return info->dtb_filename || info->get_dtb;
194 }
195 
196 #define WRITE_WORD(p, value) do { \
197     address_space_stl_notdirty(&address_space_memory, p, value, \
198                                MEMTXATTRS_UNSPECIFIED, NULL);  \
199     p += 4;                       \
200 } while (0)
201 
202 static void set_kernel_args(const struct arm_boot_info *info)
203 {
204     int initrd_size = info->initrd_size;
205     hwaddr base = info->loader_start;
206     hwaddr p;
207 
208     p = base + KERNEL_ARGS_ADDR;
209     /* ATAG_CORE */
210     WRITE_WORD(p, 5);
211     WRITE_WORD(p, 0x54410001);
212     WRITE_WORD(p, 1);
213     WRITE_WORD(p, 0x1000);
214     WRITE_WORD(p, 0);
215     /* ATAG_MEM */
216     /* TODO: handle multiple chips on one ATAG list */
217     WRITE_WORD(p, 4);
218     WRITE_WORD(p, 0x54410002);
219     WRITE_WORD(p, info->ram_size);
220     WRITE_WORD(p, info->loader_start);
221     if (initrd_size) {
222         /* ATAG_INITRD2 */
223         WRITE_WORD(p, 4);
224         WRITE_WORD(p, 0x54420005);
225         WRITE_WORD(p, info->initrd_start);
226         WRITE_WORD(p, initrd_size);
227     }
228     if (info->kernel_cmdline && *info->kernel_cmdline) {
229         /* ATAG_CMDLINE */
230         int cmdline_size;
231 
232         cmdline_size = strlen(info->kernel_cmdline);
233         cpu_physical_memory_write(p + 8, info->kernel_cmdline,
234                                   cmdline_size + 1);
235         cmdline_size = (cmdline_size >> 2) + 1;
236         WRITE_WORD(p, cmdline_size + 2);
237         WRITE_WORD(p, 0x54410009);
238         p += cmdline_size * 4;
239     }
240     if (info->atag_board) {
241         /* ATAG_BOARD */
242         int atag_board_len;
243         uint8_t atag_board_buf[0x1000];
244 
245         atag_board_len = (info->atag_board(info, atag_board_buf) + 3) & ~3;
246         WRITE_WORD(p, (atag_board_len + 8) >> 2);
247         WRITE_WORD(p, 0x414f4d50);
248         cpu_physical_memory_write(p, atag_board_buf, atag_board_len);
249         p += atag_board_len;
250     }
251     /* ATAG_END */
252     WRITE_WORD(p, 0);
253     WRITE_WORD(p, 0);
254 }
255 
256 static void set_kernel_args_old(const struct arm_boot_info *info)
257 {
258     hwaddr p;
259     const char *s;
260     int initrd_size = info->initrd_size;
261     hwaddr base = info->loader_start;
262 
263     /* see linux/include/asm-arm/setup.h */
264     p = base + KERNEL_ARGS_ADDR;
265     /* page_size */
266     WRITE_WORD(p, 4096);
267     /* nr_pages */
268     WRITE_WORD(p, info->ram_size / 4096);
269     /* ramdisk_size */
270     WRITE_WORD(p, 0);
271 #define FLAG_READONLY	1
272 #define FLAG_RDLOAD	4
273 #define FLAG_RDPROMPT	8
274     /* flags */
275     WRITE_WORD(p, FLAG_READONLY | FLAG_RDLOAD | FLAG_RDPROMPT);
276     /* rootdev */
277     WRITE_WORD(p, (31 << 8) | 0);	/* /dev/mtdblock0 */
278     /* video_num_cols */
279     WRITE_WORD(p, 0);
280     /* video_num_rows */
281     WRITE_WORD(p, 0);
282     /* video_x */
283     WRITE_WORD(p, 0);
284     /* video_y */
285     WRITE_WORD(p, 0);
286     /* memc_control_reg */
287     WRITE_WORD(p, 0);
288     /* unsigned char sounddefault */
289     /* unsigned char adfsdrives */
290     /* unsigned char bytes_per_char_h */
291     /* unsigned char bytes_per_char_v */
292     WRITE_WORD(p, 0);
293     /* pages_in_bank[4] */
294     WRITE_WORD(p, 0);
295     WRITE_WORD(p, 0);
296     WRITE_WORD(p, 0);
297     WRITE_WORD(p, 0);
298     /* pages_in_vram */
299     WRITE_WORD(p, 0);
300     /* initrd_start */
301     if (initrd_size) {
302         WRITE_WORD(p, info->initrd_start);
303     } else {
304         WRITE_WORD(p, 0);
305     }
306     /* initrd_size */
307     WRITE_WORD(p, initrd_size);
308     /* rd_start */
309     WRITE_WORD(p, 0);
310     /* system_rev */
311     WRITE_WORD(p, 0);
312     /* system_serial_low */
313     WRITE_WORD(p, 0);
314     /* system_serial_high */
315     WRITE_WORD(p, 0);
316     /* mem_fclk_21285 */
317     WRITE_WORD(p, 0);
318     /* zero unused fields */
319     while (p < base + KERNEL_ARGS_ADDR + 256 + 1024) {
320         WRITE_WORD(p, 0);
321     }
322     s = info->kernel_cmdline;
323     if (s) {
324         cpu_physical_memory_write(p, s, strlen(s) + 1);
325     } else {
326         WRITE_WORD(p, 0);
327     }
328 }
329 
330 /**
331  * load_dtb() - load a device tree binary image into memory
332  * @addr:       the address to load the image at
333  * @binfo:      struct describing the boot environment
334  * @addr_limit: upper limit of the available memory area at @addr
335  *
336  * Load a device tree supplied by the machine or by the user  with the
337  * '-dtb' command line option, and put it at offset @addr in target
338  * memory.
339  *
340  * If @addr_limit contains a meaningful value (i.e., it is strictly greater
341  * than @addr), the device tree is only loaded if its size does not exceed
342  * the limit.
343  *
344  * Returns: the size of the device tree image on success,
345  *          0 if the image size exceeds the limit,
346  *          -1 on errors.
347  *
348  * Note: Must not be called unless have_dtb(binfo) is true.
349  */
350 static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
351                     hwaddr addr_limit)
352 {
353     void *fdt = NULL;
354     int size, rc;
355     uint32_t acells, scells;
356 
357     if (binfo->dtb_filename) {
358         char *filename;
359         filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
360         if (!filename) {
361             fprintf(stderr, "Couldn't open dtb file %s\n", binfo->dtb_filename);
362             goto fail;
363         }
364 
365         fdt = load_device_tree(filename, &size);
366         if (!fdt) {
367             fprintf(stderr, "Couldn't open dtb file %s\n", filename);
368             g_free(filename);
369             goto fail;
370         }
371         g_free(filename);
372     } else {
373         fdt = binfo->get_dtb(binfo, &size);
374         if (!fdt) {
375             fprintf(stderr, "Board was unable to create a dtb blob\n");
376             goto fail;
377         }
378     }
379 
380     if (addr_limit > addr && size > (addr_limit - addr)) {
381         /* Installing the device tree blob at addr would exceed addr_limit.
382          * Whether this constitutes failure is up to the caller to decide,
383          * so just return 0 as size, i.e., no error.
384          */
385         g_free(fdt);
386         return 0;
387     }
388 
389     acells = qemu_fdt_getprop_cell(fdt, "/", "#address-cells");
390     scells = qemu_fdt_getprop_cell(fdt, "/", "#size-cells");
391     if (acells == 0 || scells == 0) {
392         fprintf(stderr, "dtb file invalid (#address-cells or #size-cells 0)\n");
393         goto fail;
394     }
395 
396     if (scells < 2 && binfo->ram_size >= (1ULL << 32)) {
397         /* This is user error so deserves a friendlier error message
398          * than the failure of setprop_sized_cells would provide
399          */
400         fprintf(stderr, "qemu: dtb file not compatible with "
401                 "RAM size > 4GB\n");
402         goto fail;
403     }
404 
405     rc = qemu_fdt_setprop_sized_cells(fdt, "/memory", "reg",
406                                       acells, binfo->loader_start,
407                                       scells, binfo->ram_size);
408     if (rc < 0) {
409         fprintf(stderr, "couldn't set /memory/reg\n");
410         goto fail;
411     }
412 
413     if (binfo->kernel_cmdline && *binfo->kernel_cmdline) {
414         rc = qemu_fdt_setprop_string(fdt, "/chosen", "bootargs",
415                                      binfo->kernel_cmdline);
416         if (rc < 0) {
417             fprintf(stderr, "couldn't set /chosen/bootargs\n");
418             goto fail;
419         }
420     }
421 
422     if (binfo->initrd_size) {
423         rc = qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-start",
424                                    binfo->initrd_start);
425         if (rc < 0) {
426             fprintf(stderr, "couldn't set /chosen/linux,initrd-start\n");
427             goto fail;
428         }
429 
430         rc = qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-end",
431                                    binfo->initrd_start + binfo->initrd_size);
432         if (rc < 0) {
433             fprintf(stderr, "couldn't set /chosen/linux,initrd-end\n");
434             goto fail;
435         }
436     }
437 
438     if (binfo->modify_dtb) {
439         binfo->modify_dtb(binfo, fdt);
440     }
441 
442     qemu_fdt_dumpdtb(fdt, size);
443 
444     /* Put the DTB into the memory map as a ROM image: this will ensure
445      * the DTB is copied again upon reset, even if addr points into RAM.
446      */
447     rom_add_blob_fixed("dtb", fdt, size, addr);
448 
449     g_free(fdt);
450 
451     return size;
452 
453 fail:
454     g_free(fdt);
455     return -1;
456 }
457 
458 static void do_cpu_reset(void *opaque)
459 {
460     ARMCPU *cpu = opaque;
461     CPUState *cs = CPU(cpu);
462     CPUARMState *env = &cpu->env;
463     const struct arm_boot_info *info = env->boot_info;
464 
465     cpu_reset(cs);
466     if (info) {
467         if (!info->is_linux) {
468             /* Jump to the entry point.  */
469             uint64_t entry = info->entry;
470 
471             if (!env->aarch64) {
472                 env->thumb = info->entry & 1;
473                 entry &= 0xfffffffe;
474             }
475             cpu_set_pc(cs, entry);
476         } else {
477             /* If we are booting Linux then we need to check whether we are
478              * booting into secure or non-secure state and adjust the state
479              * accordingly.  Out of reset, ARM is defined to be in secure state
480              * (SCR.NS = 0), we change that here if non-secure boot has been
481              * requested.
482              */
483             if (arm_feature(env, ARM_FEATURE_EL3)) {
484                 /* AArch64 is defined to come out of reset into EL3 if enabled.
485                  * If we are booting Linux then we need to adjust our EL as
486                  * Linux expects us to be in EL2 or EL1.  AArch32 resets into
487                  * SVC, which Linux expects, so no privilege/exception level to
488                  * adjust.
489                  */
490                 if (env->aarch64) {
491                     if (arm_feature(env, ARM_FEATURE_EL2)) {
492                         env->pstate = PSTATE_MODE_EL2h;
493                     } else {
494                         env->pstate = PSTATE_MODE_EL1h;
495                     }
496                 }
497 
498                 /* Set to non-secure if not a secure boot */
499                 if (!info->secure_boot &&
500                     (cs != first_cpu || !info->secure_board_setup)) {
501                     /* Linux expects non-secure state */
502                     env->cp15.scr_el3 |= SCR_NS;
503                 }
504             }
505 
506             if (cs == first_cpu) {
507                 cpu_set_pc(cs, info->loader_start);
508 
509                 if (!have_dtb(info)) {
510                     if (old_param) {
511                         set_kernel_args_old(info);
512                     } else {
513                         set_kernel_args(info);
514                     }
515                 }
516             } else {
517                 info->secondary_cpu_reset_hook(cpu, info);
518             }
519         }
520     }
521 }
522 
523 /**
524  * load_image_to_fw_cfg() - Load an image file into an fw_cfg entry identified
525  *                          by key.
526  * @fw_cfg:         The firmware config instance to store the data in.
527  * @size_key:       The firmware config key to store the size of the loaded
528  *                  data under, with fw_cfg_add_i32().
529  * @data_key:       The firmware config key to store the loaded data under,
530  *                  with fw_cfg_add_bytes().
531  * @image_name:     The name of the image file to load. If it is NULL, the
532  *                  function returns without doing anything.
533  * @try_decompress: Whether the image should be decompressed (gunzipped) before
534  *                  adding it to fw_cfg. If decompression fails, the image is
535  *                  loaded as-is.
536  *
537  * In case of failure, the function prints an error message to stderr and the
538  * process exits with status 1.
539  */
540 static void load_image_to_fw_cfg(FWCfgState *fw_cfg, uint16_t size_key,
541                                  uint16_t data_key, const char *image_name,
542                                  bool try_decompress)
543 {
544     size_t size = -1;
545     uint8_t *data;
546 
547     if (image_name == NULL) {
548         return;
549     }
550 
551     if (try_decompress) {
552         size = load_image_gzipped_buffer(image_name,
553                                          LOAD_IMAGE_MAX_GUNZIP_BYTES, &data);
554     }
555 
556     if (size == (size_t)-1) {
557         gchar *contents;
558         gsize length;
559 
560         if (!g_file_get_contents(image_name, &contents, &length, NULL)) {
561             fprintf(stderr, "failed to load \"%s\"\n", image_name);
562             exit(1);
563         }
564         size = length;
565         data = (uint8_t *)contents;
566     }
567 
568     fw_cfg_add_i32(fw_cfg, size_key, size);
569     fw_cfg_add_bytes(fw_cfg, data_key, data, size);
570 }
571 
572 static int do_arm_linux_init(Object *obj, void *opaque)
573 {
574     if (object_dynamic_cast(obj, TYPE_ARM_LINUX_BOOT_IF)) {
575         ARMLinuxBootIf *albif = ARM_LINUX_BOOT_IF(obj);
576         ARMLinuxBootIfClass *albifc = ARM_LINUX_BOOT_IF_GET_CLASS(obj);
577         struct arm_boot_info *info = opaque;
578 
579         if (albifc->arm_linux_init) {
580             albifc->arm_linux_init(albif, info->secure_boot);
581         }
582     }
583     return 0;
584 }
585 
586 static void arm_load_kernel_notify(Notifier *notifier, void *data)
587 {
588     CPUState *cs;
589     int kernel_size;
590     int initrd_size;
591     int is_linux = 0;
592     uint64_t elf_entry, elf_low_addr, elf_high_addr;
593     int elf_machine;
594     hwaddr entry, kernel_load_offset;
595     int big_endian;
596     static const ARMInsnFixup *primary_loader;
597     ArmLoadKernelNotifier *n = DO_UPCAST(ArmLoadKernelNotifier,
598                                          notifier, notifier);
599     ARMCPU *cpu = n->cpu;
600     struct arm_boot_info *info =
601         container_of(n, struct arm_boot_info, load_kernel_notifier);
602 
603     /* The board code is not supposed to set secure_board_setup unless
604      * running its code in secure mode is actually possible, and KVM
605      * doesn't support secure.
606      */
607     assert(!(info->secure_board_setup && kvm_enabled()));
608 
609     /* Load the kernel.  */
610     if (!info->kernel_filename || info->firmware_loaded) {
611 
612         if (have_dtb(info)) {
613             /* If we have a device tree blob, but no kernel to supply it to (or
614              * the kernel is supposed to be loaded by the bootloader), copy the
615              * DTB to the base of RAM for the bootloader to pick up.
616              */
617             if (load_dtb(info->loader_start, info, 0) < 0) {
618                 exit(1);
619             }
620         }
621 
622         if (info->kernel_filename) {
623             FWCfgState *fw_cfg;
624             bool try_decompressing_kernel;
625 
626             fw_cfg = fw_cfg_find();
627             try_decompressing_kernel = arm_feature(&cpu->env,
628                                                    ARM_FEATURE_AARCH64);
629 
630             /* Expose the kernel, the command line, and the initrd in fw_cfg.
631              * We don't process them here at all, it's all left to the
632              * firmware.
633              */
634             load_image_to_fw_cfg(fw_cfg,
635                                  FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA,
636                                  info->kernel_filename,
637                                  try_decompressing_kernel);
638             load_image_to_fw_cfg(fw_cfg,
639                                  FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA,
640                                  info->initrd_filename, false);
641 
642             if (info->kernel_cmdline) {
643                 fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
644                                strlen(info->kernel_cmdline) + 1);
645                 fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA,
646                                   info->kernel_cmdline);
647             }
648         }
649 
650         /* We will start from address 0 (typically a boot ROM image) in the
651          * same way as hardware.
652          */
653         return;
654     }
655 
656     if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
657         primary_loader = bootloader_aarch64;
658         kernel_load_offset = KERNEL64_LOAD_ADDR;
659         elf_machine = EM_AARCH64;
660     } else {
661         primary_loader = bootloader;
662         if (!info->write_board_setup) {
663             primary_loader += BOOTLOADER_NO_BOARD_SETUP_OFFSET;
664         }
665         kernel_load_offset = KERNEL_LOAD_ADDR;
666         elf_machine = EM_ARM;
667     }
668 
669     info->dtb_filename = qemu_opt_get(qemu_get_machine_opts(), "dtb");
670 
671     if (!info->secondary_cpu_reset_hook) {
672         info->secondary_cpu_reset_hook = default_reset_secondary;
673     }
674     if (!info->write_secondary_boot) {
675         info->write_secondary_boot = default_write_secondary;
676     }
677 
678     if (info->nb_cpus == 0)
679         info->nb_cpus = 1;
680 
681 #ifdef TARGET_WORDS_BIGENDIAN
682     big_endian = 1;
683 #else
684     big_endian = 0;
685 #endif
686 
687     /* We want to put the initrd far enough into RAM that when the
688      * kernel is uncompressed it will not clobber the initrd. However
689      * on boards without much RAM we must ensure that we still leave
690      * enough room for a decent sized initrd, and on boards with large
691      * amounts of RAM we must avoid the initrd being so far up in RAM
692      * that it is outside lowmem and inaccessible to the kernel.
693      * So for boards with less  than 256MB of RAM we put the initrd
694      * halfway into RAM, and for boards with 256MB of RAM or more we put
695      * the initrd at 128MB.
696      */
697     info->initrd_start = info->loader_start +
698         MIN(info->ram_size / 2, 128 * 1024 * 1024);
699 
700     /* Assume that raw images are linux kernels, and ELF images are not.  */
701     kernel_size = load_elf(info->kernel_filename, NULL, NULL, &elf_entry,
702                            &elf_low_addr, &elf_high_addr, big_endian,
703                            elf_machine, 1);
704     if (kernel_size > 0 && have_dtb(info)) {
705         /* If there is still some room left at the base of RAM, try and put
706          * the DTB there like we do for images loaded with -bios or -pflash.
707          */
708         if (elf_low_addr > info->loader_start
709             || elf_high_addr < info->loader_start) {
710             /* Pass elf_low_addr as address limit to load_dtb if it may be
711              * pointing into RAM, otherwise pass '0' (no limit)
712              */
713             if (elf_low_addr < info->loader_start) {
714                 elf_low_addr = 0;
715             }
716             if (load_dtb(info->loader_start, info, elf_low_addr) < 0) {
717                 exit(1);
718             }
719         }
720     }
721     entry = elf_entry;
722     if (kernel_size < 0) {
723         kernel_size = load_uimage(info->kernel_filename, &entry, NULL,
724                                   &is_linux, NULL, NULL);
725     }
726     /* On aarch64, it's the bootloader's job to uncompress the kernel. */
727     if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64) && kernel_size < 0) {
728         entry = info->loader_start + kernel_load_offset;
729         kernel_size = load_image_gzipped(info->kernel_filename, entry,
730                                          info->ram_size - kernel_load_offset);
731         is_linux = 1;
732     }
733     if (kernel_size < 0) {
734         entry = info->loader_start + kernel_load_offset;
735         kernel_size = load_image_targphys(info->kernel_filename, entry,
736                                           info->ram_size - kernel_load_offset);
737         is_linux = 1;
738     }
739     if (kernel_size < 0) {
740         fprintf(stderr, "qemu: could not load kernel '%s'\n",
741                 info->kernel_filename);
742         exit(1);
743     }
744     info->entry = entry;
745     if (is_linux) {
746         uint32_t fixupcontext[FIXUP_MAX];
747 
748         if (info->initrd_filename) {
749             initrd_size = load_ramdisk(info->initrd_filename,
750                                        info->initrd_start,
751                                        info->ram_size -
752                                        info->initrd_start);
753             if (initrd_size < 0) {
754                 initrd_size = load_image_targphys(info->initrd_filename,
755                                                   info->initrd_start,
756                                                   info->ram_size -
757                                                   info->initrd_start);
758             }
759             if (initrd_size < 0) {
760                 fprintf(stderr, "qemu: could not load initrd '%s'\n",
761                         info->initrd_filename);
762                 exit(1);
763             }
764         } else {
765             initrd_size = 0;
766         }
767         info->initrd_size = initrd_size;
768 
769         fixupcontext[FIXUP_BOARDID] = info->board_id;
770         fixupcontext[FIXUP_BOARD_SETUP] = info->board_setup_addr;
771 
772         /* for device tree boot, we pass the DTB directly in r2. Otherwise
773          * we point to the kernel args.
774          */
775         if (have_dtb(info)) {
776             hwaddr align;
777             hwaddr dtb_start;
778 
779             if (elf_machine == EM_AARCH64) {
780                 /*
781                  * Some AArch64 kernels on early bootup map the fdt region as
782                  *
783                  *   [ ALIGN_DOWN(fdt, 2MB) ... ALIGN_DOWN(fdt, 2MB) + 2MB ]
784                  *
785                  * Let's play safe and prealign it to 2MB to give us some space.
786                  */
787                 align = 2 * 1024 * 1024;
788             } else {
789                 /*
790                  * Some 32bit kernels will trash anything in the 4K page the
791                  * initrd ends in, so make sure the DTB isn't caught up in that.
792                  */
793                 align = 4096;
794             }
795 
796             /* Place the DTB after the initrd in memory with alignment. */
797             dtb_start = QEMU_ALIGN_UP(info->initrd_start + initrd_size, align);
798             if (load_dtb(dtb_start, info, 0) < 0) {
799                 exit(1);
800             }
801             fixupcontext[FIXUP_ARGPTR] = dtb_start;
802         } else {
803             fixupcontext[FIXUP_ARGPTR] = info->loader_start + KERNEL_ARGS_ADDR;
804             if (info->ram_size >= (1ULL << 32)) {
805                 fprintf(stderr, "qemu: RAM size must be less than 4GB to boot"
806                         " Linux kernel using ATAGS (try passing a device tree"
807                         " using -dtb)\n");
808                 exit(1);
809             }
810         }
811         fixupcontext[FIXUP_ENTRYPOINT] = entry;
812 
813         write_bootloader("bootloader", info->loader_start,
814                          primary_loader, fixupcontext);
815 
816         if (info->nb_cpus > 1) {
817             info->write_secondary_boot(cpu, info);
818         }
819         if (info->write_board_setup) {
820             info->write_board_setup(cpu, info);
821         }
822 
823         /* Notify devices which need to fake up firmware initialization
824          * that we're doing a direct kernel boot.
825          */
826         object_child_foreach_recursive(object_get_root(),
827                                        do_arm_linux_init, info);
828     }
829     info->is_linux = is_linux;
830 
831     for (cs = CPU(cpu); cs; cs = CPU_NEXT(cs)) {
832         ARM_CPU(cs)->env.boot_info = info;
833     }
834 }
835 
836 void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
837 {
838     CPUState *cs;
839 
840     info->load_kernel_notifier.cpu = cpu;
841     info->load_kernel_notifier.notifier.notify = arm_load_kernel_notify;
842     qemu_add_machine_init_done_notifier(&info->load_kernel_notifier.notifier);
843 
844     /* CPU objects (unlike devices) are not automatically reset on system
845      * reset, so we must always register a handler to do so. If we're
846      * actually loading a kernel, the handler is also responsible for
847      * arranging that we start it correctly.
848      */
849     for (cs = CPU(cpu); cs; cs = CPU_NEXT(cs)) {
850         qemu_register_reset(do_cpu_reset, ARM_CPU(cs));
851     }
852 }
853 
854 static const TypeInfo arm_linux_boot_if_info = {
855     .name = TYPE_ARM_LINUX_BOOT_IF,
856     .parent = TYPE_INTERFACE,
857     .class_size = sizeof(ARMLinuxBootIfClass),
858 };
859 
860 static void arm_linux_boot_register_types(void)
861 {
862     type_register_static(&arm_linux_boot_if_info);
863 }
864 
865 type_init(arm_linux_boot_register_types)
866