xref: /openbmc/qemu/hw/arm/boot.c (revision 24b94625)
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 "qemu/osdep.h"
11 #include "qapi/error.h"
12 #include "hw/hw.h"
13 #include "hw/arm/arm.h"
14 #include "hw/arm/linux-boot-if.h"
15 #include "sysemu/kvm.h"
16 #include "sysemu/sysemu.h"
17 #include "sysemu/numa.h"
18 #include "hw/boards.h"
19 #include "hw/loader.h"
20 #include "elf.h"
21 #include "sysemu/device_tree.h"
22 #include "qemu/config-file.h"
23 #include "exec/address-spaces.h"
24 
25 /* Kernel boot protocol is specified in the kernel docs
26  * Documentation/arm/Booting and Documentation/arm64/booting.txt
27  * They have different preferred image load offsets from system RAM base.
28  */
29 #define KERNEL_ARGS_ADDR 0x100
30 #define KERNEL_LOAD_ADDR 0x00010000
31 #define KERNEL64_LOAD_ADDR 0x00080000
32 
33 typedef enum {
34     FIXUP_NONE = 0,     /* do nothing */
35     FIXUP_TERMINATOR,   /* end of insns */
36     FIXUP_BOARDID,      /* overwrite with board ID number */
37     FIXUP_BOARD_SETUP,  /* overwrite with board specific setup code address */
38     FIXUP_ARGPTR,       /* overwrite with pointer to kernel args */
39     FIXUP_ENTRYPOINT,   /* overwrite with kernel entry point */
40     FIXUP_GIC_CPU_IF,   /* overwrite with GIC CPU interface address */
41     FIXUP_BOOTREG,      /* overwrite with boot register address */
42     FIXUP_DSB,          /* overwrite with correct DSB insn for cpu */
43     FIXUP_MAX,
44 } FixupType;
45 
46 typedef struct ARMInsnFixup {
47     uint32_t insn;
48     FixupType fixup;
49 } ARMInsnFixup;
50 
51 static const ARMInsnFixup bootloader_aarch64[] = {
52     { 0x580000c0 }, /* ldr x0, arg ; Load the lower 32-bits of DTB */
53     { 0xaa1f03e1 }, /* mov x1, xzr */
54     { 0xaa1f03e2 }, /* mov x2, xzr */
55     { 0xaa1f03e3 }, /* mov x3, xzr */
56     { 0x58000084 }, /* ldr x4, entry ; Load the lower 32-bits of kernel entry */
57     { 0xd61f0080 }, /* br x4      ; Jump to the kernel entry point */
58     { 0, FIXUP_ARGPTR }, /* arg: .word @DTB Lower 32-bits */
59     { 0 }, /* .word @DTB Higher 32-bits */
60     { 0, FIXUP_ENTRYPOINT }, /* entry: .word @Kernel Entry Lower 32-bits */
61     { 0 }, /* .word @Kernel Entry Higher 32-bits */
62     { 0, FIXUP_TERMINATOR }
63 };
64 
65 /* A very small bootloader: call the board-setup code (if needed),
66  * set r0-r2, then jump to the kernel.
67  * If we're not calling boot setup code then we don't copy across
68  * the first BOOTLOADER_NO_BOARD_SETUP_OFFSET insns in this array.
69  */
70 
71 static const ARMInsnFixup bootloader[] = {
72     { 0xe28fe004 }, /* add     lr, pc, #4 */
73     { 0xe51ff004 }, /* ldr     pc, [pc, #-4] */
74     { 0, FIXUP_BOARD_SETUP },
75 #define BOOTLOADER_NO_BOARD_SETUP_OFFSET 3
76     { 0xe3a00000 }, /* mov     r0, #0 */
77     { 0xe59f1004 }, /* ldr     r1, [pc, #4] */
78     { 0xe59f2004 }, /* ldr     r2, [pc, #4] */
79     { 0xe59ff004 }, /* ldr     pc, [pc, #4] */
80     { 0, FIXUP_BOARDID },
81     { 0, FIXUP_ARGPTR },
82     { 0, FIXUP_ENTRYPOINT },
83     { 0, FIXUP_TERMINATOR }
84 };
85 
86 /* Handling for secondary CPU boot in a multicore system.
87  * Unlike the uniprocessor/primary CPU boot, this is platform
88  * dependent. The default code here is based on the secondary
89  * CPU boot protocol used on realview/vexpress boards, with
90  * some parameterisation to increase its flexibility.
91  * QEMU platform models for which this code is not appropriate
92  * should override write_secondary_boot and secondary_cpu_reset_hook
93  * instead.
94  *
95  * This code enables the interrupt controllers for the secondary
96  * CPUs and then puts all the secondary CPUs into a loop waiting
97  * for an interprocessor interrupt and polling a configurable
98  * location for the kernel secondary CPU entry point.
99  */
100 #define DSB_INSN 0xf57ff04f
101 #define CP15_DSB_INSN 0xee070f9a /* mcr cp15, 0, r0, c7, c10, 4 */
102 
103 static const ARMInsnFixup smpboot[] = {
104     { 0xe59f2028 }, /* ldr r2, gic_cpu_if */
105     { 0xe59f0028 }, /* ldr r0, bootreg_addr */
106     { 0xe3a01001 }, /* mov r1, #1 */
107     { 0xe5821000 }, /* str r1, [r2] - set GICC_CTLR.Enable */
108     { 0xe3a010ff }, /* mov r1, #0xff */
109     { 0xe5821004 }, /* str r1, [r2, 4] - set GIC_PMR.Priority to 0xff */
110     { 0, FIXUP_DSB },   /* dsb */
111     { 0xe320f003 }, /* wfi */
112     { 0xe5901000 }, /* ldr     r1, [r0] */
113     { 0xe1110001 }, /* tst     r1, r1 */
114     { 0x0afffffb }, /* beq     <wfi> */
115     { 0xe12fff11 }, /* bx      r1 */
116     { 0, FIXUP_GIC_CPU_IF }, /* gic_cpu_if: .word 0x.... */
117     { 0, FIXUP_BOOTREG }, /* bootreg_addr: .word 0x.... */
118     { 0, FIXUP_TERMINATOR }
119 };
120 
121 static void write_bootloader(const char *name, hwaddr addr,
122                              const ARMInsnFixup *insns, uint32_t *fixupcontext)
123 {
124     /* Fix up the specified bootloader fragment and write it into
125      * guest memory using rom_add_blob_fixed(). fixupcontext is
126      * an array giving the values to write in for the fixup types
127      * which write a value into the code array.
128      */
129     int i, len;
130     uint32_t *code;
131 
132     len = 0;
133     while (insns[len].fixup != FIXUP_TERMINATOR) {
134         len++;
135     }
136 
137     code = g_new0(uint32_t, len);
138 
139     for (i = 0; i < len; i++) {
140         uint32_t insn = insns[i].insn;
141         FixupType fixup = insns[i].fixup;
142 
143         switch (fixup) {
144         case FIXUP_NONE:
145             break;
146         case FIXUP_BOARDID:
147         case FIXUP_BOARD_SETUP:
148         case FIXUP_ARGPTR:
149         case FIXUP_ENTRYPOINT:
150         case FIXUP_GIC_CPU_IF:
151         case FIXUP_BOOTREG:
152         case FIXUP_DSB:
153             insn = fixupcontext[fixup];
154             break;
155         default:
156             abort();
157         }
158         code[i] = tswap32(insn);
159     }
160 
161     rom_add_blob_fixed(name, code, len * sizeof(uint32_t), addr);
162 
163     g_free(code);
164 }
165 
166 static void default_write_secondary(ARMCPU *cpu,
167                                     const struct arm_boot_info *info)
168 {
169     uint32_t fixupcontext[FIXUP_MAX];
170 
171     fixupcontext[FIXUP_GIC_CPU_IF] = info->gic_cpu_if_addr;
172     fixupcontext[FIXUP_BOOTREG] = info->smp_bootreg_addr;
173     if (arm_feature(&cpu->env, ARM_FEATURE_V7)) {
174         fixupcontext[FIXUP_DSB] = DSB_INSN;
175     } else {
176         fixupcontext[FIXUP_DSB] = CP15_DSB_INSN;
177     }
178 
179     write_bootloader("smpboot", info->smp_loader_start,
180                      smpboot, fixupcontext);
181 }
182 
183 void arm_write_secure_board_setup_dummy_smc(ARMCPU *cpu,
184                                             const struct arm_boot_info *info,
185                                             hwaddr mvbar_addr)
186 {
187     int n;
188     uint32_t mvbar_blob[] = {
189         /* mvbar_addr: secure monitor vectors
190          * Default unimplemented and unused vectors to spin. Makes it
191          * easier to debug (as opposed to the CPU running away).
192          */
193         0xeafffffe, /* (spin) */
194         0xeafffffe, /* (spin) */
195         0xe1b0f00e, /* movs pc, lr ;SMC exception return */
196         0xeafffffe, /* (spin) */
197         0xeafffffe, /* (spin) */
198         0xeafffffe, /* (spin) */
199         0xeafffffe, /* (spin) */
200         0xeafffffe, /* (spin) */
201     };
202     uint32_t board_setup_blob[] = {
203         /* board setup addr */
204         0xe3a00e00 + (mvbar_addr >> 4), /* mov r0, #mvbar_addr */
205         0xee0c0f30, /* mcr     p15, 0, r0, c12, c0, 1 ;set MVBAR */
206         0xee110f11, /* mrc     p15, 0, r0, c1 , c1, 0 ;read SCR */
207         0xe3800031, /* orr     r0, #0x31              ;enable AW, FW, NS */
208         0xee010f11, /* mcr     p15, 0, r0, c1, c1, 0  ;write SCR */
209         0xe1a0100e, /* mov     r1, lr                 ;save LR across SMC */
210         0xe1600070, /* smc     #0                     ;call monitor to flush SCR */
211         0xe1a0f001, /* mov     pc, r1                 ;return */
212     };
213 
214     /* check that mvbar_addr is correctly aligned and relocatable (using MOV) */
215     assert((mvbar_addr & 0x1f) == 0 && (mvbar_addr >> 4) < 0x100);
216 
217     /* check that these blobs don't overlap */
218     assert((mvbar_addr + sizeof(mvbar_blob) <= info->board_setup_addr)
219           || (info->board_setup_addr + sizeof(board_setup_blob) <= mvbar_addr));
220 
221     for (n = 0; n < ARRAY_SIZE(mvbar_blob); n++) {
222         mvbar_blob[n] = tswap32(mvbar_blob[n]);
223     }
224     rom_add_blob_fixed("board-setup-mvbar", mvbar_blob, sizeof(mvbar_blob),
225                        mvbar_addr);
226 
227     for (n = 0; n < ARRAY_SIZE(board_setup_blob); n++) {
228         board_setup_blob[n] = tswap32(board_setup_blob[n]);
229     }
230     rom_add_blob_fixed("board-setup", board_setup_blob,
231                        sizeof(board_setup_blob), info->board_setup_addr);
232 }
233 
234 static void default_reset_secondary(ARMCPU *cpu,
235                                     const struct arm_boot_info *info)
236 {
237     CPUState *cs = CPU(cpu);
238 
239     address_space_stl_notdirty(&address_space_memory, info->smp_bootreg_addr,
240                                0, MEMTXATTRS_UNSPECIFIED, NULL);
241     cpu_set_pc(cs, info->smp_loader_start);
242 }
243 
244 static inline bool have_dtb(const struct arm_boot_info *info)
245 {
246     return info->dtb_filename || info->get_dtb;
247 }
248 
249 #define WRITE_WORD(p, value) do { \
250     address_space_stl_notdirty(&address_space_memory, p, value, \
251                                MEMTXATTRS_UNSPECIFIED, NULL);  \
252     p += 4;                       \
253 } while (0)
254 
255 static void set_kernel_args(const struct arm_boot_info *info)
256 {
257     int initrd_size = info->initrd_size;
258     hwaddr base = info->loader_start;
259     hwaddr p;
260 
261     p = base + KERNEL_ARGS_ADDR;
262     /* ATAG_CORE */
263     WRITE_WORD(p, 5);
264     WRITE_WORD(p, 0x54410001);
265     WRITE_WORD(p, 1);
266     WRITE_WORD(p, 0x1000);
267     WRITE_WORD(p, 0);
268     /* ATAG_MEM */
269     /* TODO: handle multiple chips on one ATAG list */
270     WRITE_WORD(p, 4);
271     WRITE_WORD(p, 0x54410002);
272     WRITE_WORD(p, info->ram_size);
273     WRITE_WORD(p, info->loader_start);
274     if (initrd_size) {
275         /* ATAG_INITRD2 */
276         WRITE_WORD(p, 4);
277         WRITE_WORD(p, 0x54420005);
278         WRITE_WORD(p, info->initrd_start);
279         WRITE_WORD(p, initrd_size);
280     }
281     if (info->kernel_cmdline && *info->kernel_cmdline) {
282         /* ATAG_CMDLINE */
283         int cmdline_size;
284 
285         cmdline_size = strlen(info->kernel_cmdline);
286         cpu_physical_memory_write(p + 8, info->kernel_cmdline,
287                                   cmdline_size + 1);
288         cmdline_size = (cmdline_size >> 2) + 1;
289         WRITE_WORD(p, cmdline_size + 2);
290         WRITE_WORD(p, 0x54410009);
291         p += cmdline_size * 4;
292     }
293     if (info->atag_board) {
294         /* ATAG_BOARD */
295         int atag_board_len;
296         uint8_t atag_board_buf[0x1000];
297 
298         atag_board_len = (info->atag_board(info, atag_board_buf) + 3) & ~3;
299         WRITE_WORD(p, (atag_board_len + 8) >> 2);
300         WRITE_WORD(p, 0x414f4d50);
301         cpu_physical_memory_write(p, atag_board_buf, atag_board_len);
302         p += atag_board_len;
303     }
304     /* ATAG_END */
305     WRITE_WORD(p, 0);
306     WRITE_WORD(p, 0);
307 }
308 
309 static void set_kernel_args_old(const struct arm_boot_info *info)
310 {
311     hwaddr p;
312     const char *s;
313     int initrd_size = info->initrd_size;
314     hwaddr base = info->loader_start;
315 
316     /* see linux/include/asm-arm/setup.h */
317     p = base + KERNEL_ARGS_ADDR;
318     /* page_size */
319     WRITE_WORD(p, 4096);
320     /* nr_pages */
321     WRITE_WORD(p, info->ram_size / 4096);
322     /* ramdisk_size */
323     WRITE_WORD(p, 0);
324 #define FLAG_READONLY	1
325 #define FLAG_RDLOAD	4
326 #define FLAG_RDPROMPT	8
327     /* flags */
328     WRITE_WORD(p, FLAG_READONLY | FLAG_RDLOAD | FLAG_RDPROMPT);
329     /* rootdev */
330     WRITE_WORD(p, (31 << 8) | 0);	/* /dev/mtdblock0 */
331     /* video_num_cols */
332     WRITE_WORD(p, 0);
333     /* video_num_rows */
334     WRITE_WORD(p, 0);
335     /* video_x */
336     WRITE_WORD(p, 0);
337     /* video_y */
338     WRITE_WORD(p, 0);
339     /* memc_control_reg */
340     WRITE_WORD(p, 0);
341     /* unsigned char sounddefault */
342     /* unsigned char adfsdrives */
343     /* unsigned char bytes_per_char_h */
344     /* unsigned char bytes_per_char_v */
345     WRITE_WORD(p, 0);
346     /* pages_in_bank[4] */
347     WRITE_WORD(p, 0);
348     WRITE_WORD(p, 0);
349     WRITE_WORD(p, 0);
350     WRITE_WORD(p, 0);
351     /* pages_in_vram */
352     WRITE_WORD(p, 0);
353     /* initrd_start */
354     if (initrd_size) {
355         WRITE_WORD(p, info->initrd_start);
356     } else {
357         WRITE_WORD(p, 0);
358     }
359     /* initrd_size */
360     WRITE_WORD(p, initrd_size);
361     /* rd_start */
362     WRITE_WORD(p, 0);
363     /* system_rev */
364     WRITE_WORD(p, 0);
365     /* system_serial_low */
366     WRITE_WORD(p, 0);
367     /* system_serial_high */
368     WRITE_WORD(p, 0);
369     /* mem_fclk_21285 */
370     WRITE_WORD(p, 0);
371     /* zero unused fields */
372     while (p < base + KERNEL_ARGS_ADDR + 256 + 1024) {
373         WRITE_WORD(p, 0);
374     }
375     s = info->kernel_cmdline;
376     if (s) {
377         cpu_physical_memory_write(p, s, strlen(s) + 1);
378     } else {
379         WRITE_WORD(p, 0);
380     }
381 }
382 
383 /**
384  * load_dtb() - load a device tree binary image into memory
385  * @addr:       the address to load the image at
386  * @binfo:      struct describing the boot environment
387  * @addr_limit: upper limit of the available memory area at @addr
388  *
389  * Load a device tree supplied by the machine or by the user  with the
390  * '-dtb' command line option, and put it at offset @addr in target
391  * memory.
392  *
393  * If @addr_limit contains a meaningful value (i.e., it is strictly greater
394  * than @addr), the device tree is only loaded if its size does not exceed
395  * the limit.
396  *
397  * Returns: the size of the device tree image on success,
398  *          0 if the image size exceeds the limit,
399  *          -1 on errors.
400  *
401  * Note: Must not be called unless have_dtb(binfo) is true.
402  */
403 static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
404                     hwaddr addr_limit)
405 {
406     void *fdt = NULL;
407     int size, rc;
408     uint32_t acells, scells;
409     char *nodename;
410     unsigned int i;
411     hwaddr mem_base, mem_len;
412 
413     if (binfo->dtb_filename) {
414         char *filename;
415         filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
416         if (!filename) {
417             fprintf(stderr, "Couldn't open dtb file %s\n", binfo->dtb_filename);
418             goto fail;
419         }
420 
421         fdt = load_device_tree(filename, &size);
422         if (!fdt) {
423             fprintf(stderr, "Couldn't open dtb file %s\n", filename);
424             g_free(filename);
425             goto fail;
426         }
427         g_free(filename);
428     } else {
429         fdt = binfo->get_dtb(binfo, &size);
430         if (!fdt) {
431             fprintf(stderr, "Board was unable to create a dtb blob\n");
432             goto fail;
433         }
434     }
435 
436     if (addr_limit > addr && size > (addr_limit - addr)) {
437         /* Installing the device tree blob at addr would exceed addr_limit.
438          * Whether this constitutes failure is up to the caller to decide,
439          * so just return 0 as size, i.e., no error.
440          */
441         g_free(fdt);
442         return 0;
443     }
444 
445     acells = qemu_fdt_getprop_cell(fdt, "/", "#address-cells",
446                                    NULL, &error_fatal);
447     scells = qemu_fdt_getprop_cell(fdt, "/", "#size-cells",
448                                    NULL, &error_fatal);
449     if (acells == 0 || scells == 0) {
450         fprintf(stderr, "dtb file invalid (#address-cells or #size-cells 0)\n");
451         goto fail;
452     }
453 
454     if (scells < 2 && binfo->ram_size >= (1ULL << 32)) {
455         /* This is user error so deserves a friendlier error message
456          * than the failure of setprop_sized_cells would provide
457          */
458         fprintf(stderr, "qemu: dtb file not compatible with "
459                 "RAM size > 4GB\n");
460         goto fail;
461     }
462 
463     if (nb_numa_nodes > 0) {
464         /*
465          * Turn the /memory node created before into a NOP node, then create
466          * /memory@addr nodes for all numa nodes respectively.
467          */
468         qemu_fdt_nop_node(fdt, "/memory");
469         mem_base = binfo->loader_start;
470         for (i = 0; i < nb_numa_nodes; i++) {
471             mem_len = numa_info[i].node_mem;
472             nodename = g_strdup_printf("/memory@%" PRIx64, mem_base);
473             qemu_fdt_add_subnode(fdt, nodename);
474             qemu_fdt_setprop_string(fdt, nodename, "device_type", "memory");
475             rc = qemu_fdt_setprop_sized_cells(fdt, nodename, "reg",
476                                               acells, mem_base,
477                                               scells, mem_len);
478             if (rc < 0) {
479                 fprintf(stderr, "couldn't set %s/reg for node %d\n", nodename,
480                         i);
481                 goto fail;
482             }
483 
484             qemu_fdt_setprop_cell(fdt, nodename, "numa-node-id", i);
485             mem_base += mem_len;
486             g_free(nodename);
487         }
488     } else {
489         rc = qemu_fdt_setprop_sized_cells(fdt, "/memory", "reg",
490                                           acells, binfo->loader_start,
491                                           scells, binfo->ram_size);
492         if (rc < 0) {
493             fprintf(stderr, "couldn't set /memory/reg\n");
494             goto fail;
495         }
496     }
497 
498     if (binfo->kernel_cmdline && *binfo->kernel_cmdline) {
499         rc = qemu_fdt_setprop_string(fdt, "/chosen", "bootargs",
500                                      binfo->kernel_cmdline);
501         if (rc < 0) {
502             fprintf(stderr, "couldn't set /chosen/bootargs\n");
503             goto fail;
504         }
505     }
506 
507     if (binfo->initrd_size) {
508         rc = qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-start",
509                                    binfo->initrd_start);
510         if (rc < 0) {
511             fprintf(stderr, "couldn't set /chosen/linux,initrd-start\n");
512             goto fail;
513         }
514 
515         rc = qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-end",
516                                    binfo->initrd_start + binfo->initrd_size);
517         if (rc < 0) {
518             fprintf(stderr, "couldn't set /chosen/linux,initrd-end\n");
519             goto fail;
520         }
521     }
522 
523     if (binfo->modify_dtb) {
524         binfo->modify_dtb(binfo, fdt);
525     }
526 
527     qemu_fdt_dumpdtb(fdt, size);
528 
529     /* Put the DTB into the memory map as a ROM image: this will ensure
530      * the DTB is copied again upon reset, even if addr points into RAM.
531      */
532     rom_add_blob_fixed("dtb", fdt, size, addr);
533 
534     g_free(fdt);
535 
536     return size;
537 
538 fail:
539     g_free(fdt);
540     return -1;
541 }
542 
543 static void do_cpu_reset(void *opaque)
544 {
545     ARMCPU *cpu = opaque;
546     CPUState *cs = CPU(cpu);
547     CPUARMState *env = &cpu->env;
548     const struct arm_boot_info *info = env->boot_info;
549 
550     cpu_reset(cs);
551     if (info) {
552         if (!info->is_linux) {
553             int i;
554             /* Jump to the entry point.  */
555             uint64_t entry = info->entry;
556 
557             switch (info->endianness) {
558             case ARM_ENDIANNESS_LE:
559                 env->cp15.sctlr_el[1] &= ~SCTLR_E0E;
560                 for (i = 1; i < 4; ++i) {
561                     env->cp15.sctlr_el[i] &= ~SCTLR_EE;
562                 }
563                 env->uncached_cpsr &= ~CPSR_E;
564                 break;
565             case ARM_ENDIANNESS_BE8:
566                 env->cp15.sctlr_el[1] |= SCTLR_E0E;
567                 for (i = 1; i < 4; ++i) {
568                     env->cp15.sctlr_el[i] |= SCTLR_EE;
569                 }
570                 env->uncached_cpsr |= CPSR_E;
571                 break;
572             case ARM_ENDIANNESS_BE32:
573                 env->cp15.sctlr_el[1] |= SCTLR_B;
574                 break;
575             case ARM_ENDIANNESS_UNKNOWN:
576                 break; /* Board's decision */
577             default:
578                 g_assert_not_reached();
579             }
580 
581             if (!env->aarch64) {
582                 env->thumb = info->entry & 1;
583                 entry &= 0xfffffffe;
584             }
585             cpu_set_pc(cs, entry);
586         } else {
587             /* If we are booting Linux then we need to check whether we are
588              * booting into secure or non-secure state and adjust the state
589              * accordingly.  Out of reset, ARM is defined to be in secure state
590              * (SCR.NS = 0), we change that here if non-secure boot has been
591              * requested.
592              */
593             if (arm_feature(env, ARM_FEATURE_EL3)) {
594                 /* AArch64 is defined to come out of reset into EL3 if enabled.
595                  * If we are booting Linux then we need to adjust our EL as
596                  * Linux expects us to be in EL2 or EL1.  AArch32 resets into
597                  * SVC, which Linux expects, so no privilege/exception level to
598                  * adjust.
599                  */
600                 if (env->aarch64) {
601                     env->cp15.scr_el3 |= SCR_RW;
602                     if (arm_feature(env, ARM_FEATURE_EL2)) {
603                         env->cp15.hcr_el2 |= HCR_RW;
604                         env->pstate = PSTATE_MODE_EL2h;
605                     } else {
606                         env->pstate = PSTATE_MODE_EL1h;
607                     }
608                 }
609 
610                 /* Set to non-secure if not a secure boot */
611                 if (!info->secure_boot &&
612                     (cs != first_cpu || !info->secure_board_setup)) {
613                     /* Linux expects non-secure state */
614                     env->cp15.scr_el3 |= SCR_NS;
615                 }
616             }
617 
618             if (cs == first_cpu) {
619                 cpu_set_pc(cs, info->loader_start);
620 
621                 if (!have_dtb(info)) {
622                     if (old_param) {
623                         set_kernel_args_old(info);
624                     } else {
625                         set_kernel_args(info);
626                     }
627                 }
628             } else {
629                 info->secondary_cpu_reset_hook(cpu, info);
630             }
631         }
632     }
633 }
634 
635 /**
636  * load_image_to_fw_cfg() - Load an image file into an fw_cfg entry identified
637  *                          by key.
638  * @fw_cfg:         The firmware config instance to store the data in.
639  * @size_key:       The firmware config key to store the size of the loaded
640  *                  data under, with fw_cfg_add_i32().
641  * @data_key:       The firmware config key to store the loaded data under,
642  *                  with fw_cfg_add_bytes().
643  * @image_name:     The name of the image file to load. If it is NULL, the
644  *                  function returns without doing anything.
645  * @try_decompress: Whether the image should be decompressed (gunzipped) before
646  *                  adding it to fw_cfg. If decompression fails, the image is
647  *                  loaded as-is.
648  *
649  * In case of failure, the function prints an error message to stderr and the
650  * process exits with status 1.
651  */
652 static void load_image_to_fw_cfg(FWCfgState *fw_cfg, uint16_t size_key,
653                                  uint16_t data_key, const char *image_name,
654                                  bool try_decompress)
655 {
656     size_t size = -1;
657     uint8_t *data;
658 
659     if (image_name == NULL) {
660         return;
661     }
662 
663     if (try_decompress) {
664         size = load_image_gzipped_buffer(image_name,
665                                          LOAD_IMAGE_MAX_GUNZIP_BYTES, &data);
666     }
667 
668     if (size == (size_t)-1) {
669         gchar *contents;
670         gsize length;
671 
672         if (!g_file_get_contents(image_name, &contents, &length, NULL)) {
673             fprintf(stderr, "failed to load \"%s\"\n", image_name);
674             exit(1);
675         }
676         size = length;
677         data = (uint8_t *)contents;
678     }
679 
680     fw_cfg_add_i32(fw_cfg, size_key, size);
681     fw_cfg_add_bytes(fw_cfg, data_key, data, size);
682 }
683 
684 static int do_arm_linux_init(Object *obj, void *opaque)
685 {
686     if (object_dynamic_cast(obj, TYPE_ARM_LINUX_BOOT_IF)) {
687         ARMLinuxBootIf *albif = ARM_LINUX_BOOT_IF(obj);
688         ARMLinuxBootIfClass *albifc = ARM_LINUX_BOOT_IF_GET_CLASS(obj);
689         struct arm_boot_info *info = opaque;
690 
691         if (albifc->arm_linux_init) {
692             albifc->arm_linux_init(albif, info->secure_boot);
693         }
694     }
695     return 0;
696 }
697 
698 static uint64_t arm_load_elf(struct arm_boot_info *info, uint64_t *pentry,
699                              uint64_t *lowaddr, uint64_t *highaddr,
700                              int elf_machine)
701 {
702     bool elf_is64;
703     union {
704         Elf32_Ehdr h32;
705         Elf64_Ehdr h64;
706     } elf_header;
707     int data_swab = 0;
708     bool big_endian;
709     uint64_t ret = -1;
710     Error *err = NULL;
711 
712 
713     load_elf_hdr(info->kernel_filename, &elf_header, &elf_is64, &err);
714     if (err) {
715         return ret;
716     }
717 
718     if (elf_is64) {
719         big_endian = elf_header.h64.e_ident[EI_DATA] == ELFDATA2MSB;
720         info->endianness = big_endian ? ARM_ENDIANNESS_BE8
721                                       : ARM_ENDIANNESS_LE;
722     } else {
723         big_endian = elf_header.h32.e_ident[EI_DATA] == ELFDATA2MSB;
724         if (big_endian) {
725             if (bswap32(elf_header.h32.e_flags) & EF_ARM_BE8) {
726                 info->endianness = ARM_ENDIANNESS_BE8;
727             } else {
728                 info->endianness = ARM_ENDIANNESS_BE32;
729                 /* In BE32, the CPU has a different view of the per-byte
730                  * address map than the rest of the system. BE32 ELF files
731                  * are organised such that they can be programmed through
732                  * the CPU's per-word byte-reversed view of the world. QEMU
733                  * however loads ELF files independently of the CPU. So
734                  * tell the ELF loader to byte reverse the data for us.
735                  */
736                 data_swab = 2;
737             }
738         } else {
739             info->endianness = ARM_ENDIANNESS_LE;
740         }
741     }
742 
743     ret = load_elf(info->kernel_filename, NULL, NULL,
744                    pentry, lowaddr, highaddr, big_endian, elf_machine,
745                    1, data_swab);
746     if (ret <= 0) {
747         /* The header loaded but the image didn't */
748         exit(1);
749     }
750 
751     return ret;
752 }
753 
754 static void arm_load_kernel_notify(Notifier *notifier, void *data)
755 {
756     CPUState *cs;
757     int kernel_size;
758     int initrd_size;
759     int is_linux = 0;
760     uint64_t elf_entry, elf_low_addr, elf_high_addr;
761     int elf_machine;
762     hwaddr entry, kernel_load_offset;
763     static const ARMInsnFixup *primary_loader;
764     ArmLoadKernelNotifier *n = DO_UPCAST(ArmLoadKernelNotifier,
765                                          notifier, notifier);
766     ARMCPU *cpu = n->cpu;
767     struct arm_boot_info *info =
768         container_of(n, struct arm_boot_info, load_kernel_notifier);
769 
770     /* The board code is not supposed to set secure_board_setup unless
771      * running its code in secure mode is actually possible, and KVM
772      * doesn't support secure.
773      */
774     assert(!(info->secure_board_setup && kvm_enabled()));
775 
776     info->dtb_filename = qemu_opt_get(qemu_get_machine_opts(), "dtb");
777 
778     /* Load the kernel.  */
779     if (!info->kernel_filename || info->firmware_loaded) {
780 
781         if (have_dtb(info)) {
782             /* If we have a device tree blob, but no kernel to supply it to (or
783              * the kernel is supposed to be loaded by the bootloader), copy the
784              * DTB to the base of RAM for the bootloader to pick up.
785              */
786             if (load_dtb(info->loader_start, info, 0) < 0) {
787                 exit(1);
788             }
789         }
790 
791         if (info->kernel_filename) {
792             FWCfgState *fw_cfg;
793             bool try_decompressing_kernel;
794 
795             fw_cfg = fw_cfg_find();
796             try_decompressing_kernel = arm_feature(&cpu->env,
797                                                    ARM_FEATURE_AARCH64);
798 
799             /* Expose the kernel, the command line, and the initrd in fw_cfg.
800              * We don't process them here at all, it's all left to the
801              * firmware.
802              */
803             load_image_to_fw_cfg(fw_cfg,
804                                  FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA,
805                                  info->kernel_filename,
806                                  try_decompressing_kernel);
807             load_image_to_fw_cfg(fw_cfg,
808                                  FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA,
809                                  info->initrd_filename, false);
810 
811             if (info->kernel_cmdline) {
812                 fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
813                                strlen(info->kernel_cmdline) + 1);
814                 fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA,
815                                   info->kernel_cmdline);
816             }
817         }
818 
819         /* We will start from address 0 (typically a boot ROM image) in the
820          * same way as hardware.
821          */
822         return;
823     }
824 
825     if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
826         primary_loader = bootloader_aarch64;
827         kernel_load_offset = KERNEL64_LOAD_ADDR;
828         elf_machine = EM_AARCH64;
829     } else {
830         primary_loader = bootloader;
831         if (!info->write_board_setup) {
832             primary_loader += BOOTLOADER_NO_BOARD_SETUP_OFFSET;
833         }
834         kernel_load_offset = KERNEL_LOAD_ADDR;
835         elf_machine = EM_ARM;
836     }
837 
838     if (!info->secondary_cpu_reset_hook) {
839         info->secondary_cpu_reset_hook = default_reset_secondary;
840     }
841     if (!info->write_secondary_boot) {
842         info->write_secondary_boot = default_write_secondary;
843     }
844 
845     if (info->nb_cpus == 0)
846         info->nb_cpus = 1;
847 
848     /* We want to put the initrd far enough into RAM that when the
849      * kernel is uncompressed it will not clobber the initrd. However
850      * on boards without much RAM we must ensure that we still leave
851      * enough room for a decent sized initrd, and on boards with large
852      * amounts of RAM we must avoid the initrd being so far up in RAM
853      * that it is outside lowmem and inaccessible to the kernel.
854      * So for boards with less  than 256MB of RAM we put the initrd
855      * halfway into RAM, and for boards with 256MB of RAM or more we put
856      * the initrd at 128MB.
857      */
858     info->initrd_start = info->loader_start +
859         MIN(info->ram_size / 2, 128 * 1024 * 1024);
860 
861     /* Assume that raw images are linux kernels, and ELF images are not.  */
862     kernel_size = arm_load_elf(info, &elf_entry, &elf_low_addr,
863                                &elf_high_addr, elf_machine);
864     if (kernel_size > 0 && have_dtb(info)) {
865         /* If there is still some room left at the base of RAM, try and put
866          * the DTB there like we do for images loaded with -bios or -pflash.
867          */
868         if (elf_low_addr > info->loader_start
869             || elf_high_addr < info->loader_start) {
870             /* Pass elf_low_addr as address limit to load_dtb if it may be
871              * pointing into RAM, otherwise pass '0' (no limit)
872              */
873             if (elf_low_addr < info->loader_start) {
874                 elf_low_addr = 0;
875             }
876             if (load_dtb(info->loader_start, info, elf_low_addr) < 0) {
877                 exit(1);
878             }
879         }
880     }
881     entry = elf_entry;
882     if (kernel_size < 0) {
883         kernel_size = load_uimage(info->kernel_filename, &entry, NULL,
884                                   &is_linux, NULL, NULL);
885     }
886     /* On aarch64, it's the bootloader's job to uncompress the kernel. */
887     if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64) && kernel_size < 0) {
888         entry = info->loader_start + kernel_load_offset;
889         kernel_size = load_image_gzipped(info->kernel_filename, entry,
890                                          info->ram_size - kernel_load_offset);
891         is_linux = 1;
892     }
893     if (kernel_size < 0) {
894         entry = info->loader_start + kernel_load_offset;
895         kernel_size = load_image_targphys(info->kernel_filename, entry,
896                                           info->ram_size - kernel_load_offset);
897         is_linux = 1;
898     }
899     if (kernel_size < 0) {
900         fprintf(stderr, "qemu: could not load kernel '%s'\n",
901                 info->kernel_filename);
902         exit(1);
903     }
904     info->entry = entry;
905     if (is_linux) {
906         uint32_t fixupcontext[FIXUP_MAX];
907 
908         if (info->initrd_filename) {
909             initrd_size = load_ramdisk(info->initrd_filename,
910                                        info->initrd_start,
911                                        info->ram_size -
912                                        info->initrd_start);
913             if (initrd_size < 0) {
914                 initrd_size = load_image_targphys(info->initrd_filename,
915                                                   info->initrd_start,
916                                                   info->ram_size -
917                                                   info->initrd_start);
918             }
919             if (initrd_size < 0) {
920                 fprintf(stderr, "qemu: could not load initrd '%s'\n",
921                         info->initrd_filename);
922                 exit(1);
923             }
924         } else {
925             initrd_size = 0;
926         }
927         info->initrd_size = initrd_size;
928 
929         fixupcontext[FIXUP_BOARDID] = info->board_id;
930         fixupcontext[FIXUP_BOARD_SETUP] = info->board_setup_addr;
931 
932         /* for device tree boot, we pass the DTB directly in r2. Otherwise
933          * we point to the kernel args.
934          */
935         if (have_dtb(info)) {
936             hwaddr align;
937             hwaddr dtb_start;
938 
939             if (elf_machine == EM_AARCH64) {
940                 /*
941                  * Some AArch64 kernels on early bootup map the fdt region as
942                  *
943                  *   [ ALIGN_DOWN(fdt, 2MB) ... ALIGN_DOWN(fdt, 2MB) + 2MB ]
944                  *
945                  * Let's play safe and prealign it to 2MB to give us some space.
946                  */
947                 align = 2 * 1024 * 1024;
948             } else {
949                 /*
950                  * Some 32bit kernels will trash anything in the 4K page the
951                  * initrd ends in, so make sure the DTB isn't caught up in that.
952                  */
953                 align = 4096;
954             }
955 
956             /* Place the DTB after the initrd in memory with alignment. */
957             dtb_start = QEMU_ALIGN_UP(info->initrd_start + initrd_size, align);
958             if (load_dtb(dtb_start, info, 0) < 0) {
959                 exit(1);
960             }
961             fixupcontext[FIXUP_ARGPTR] = dtb_start;
962         } else {
963             fixupcontext[FIXUP_ARGPTR] = info->loader_start + KERNEL_ARGS_ADDR;
964             if (info->ram_size >= (1ULL << 32)) {
965                 fprintf(stderr, "qemu: RAM size must be less than 4GB to boot"
966                         " Linux kernel using ATAGS (try passing a device tree"
967                         " using -dtb)\n");
968                 exit(1);
969             }
970         }
971         fixupcontext[FIXUP_ENTRYPOINT] = entry;
972 
973         write_bootloader("bootloader", info->loader_start,
974                          primary_loader, fixupcontext);
975 
976         if (info->nb_cpus > 1) {
977             info->write_secondary_boot(cpu, info);
978         }
979         if (info->write_board_setup) {
980             info->write_board_setup(cpu, info);
981         }
982 
983         /* Notify devices which need to fake up firmware initialization
984          * that we're doing a direct kernel boot.
985          */
986         object_child_foreach_recursive(object_get_root(),
987                                        do_arm_linux_init, info);
988     }
989     info->is_linux = is_linux;
990 
991     for (cs = CPU(cpu); cs; cs = CPU_NEXT(cs)) {
992         ARM_CPU(cs)->env.boot_info = info;
993     }
994 }
995 
996 void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
997 {
998     CPUState *cs;
999 
1000     info->load_kernel_notifier.cpu = cpu;
1001     info->load_kernel_notifier.notifier.notify = arm_load_kernel_notify;
1002     qemu_add_machine_init_done_notifier(&info->load_kernel_notifier.notifier);
1003 
1004     /* CPU objects (unlike devices) are not automatically reset on system
1005      * reset, so we must always register a handler to do so. If we're
1006      * actually loading a kernel, the handler is also responsible for
1007      * arranging that we start it correctly.
1008      */
1009     for (cs = CPU(cpu); cs; cs = CPU_NEXT(cs)) {
1010         qemu_register_reset(do_cpu_reset, ARM_CPU(cs));
1011     }
1012 }
1013 
1014 static const TypeInfo arm_linux_boot_if_info = {
1015     .name = TYPE_ARM_LINUX_BOOT_IF,
1016     .parent = TYPE_INTERFACE,
1017     .class_size = sizeof(ARMLinuxBootIfClass),
1018 };
1019 
1020 static void arm_linux_boot_register_types(void)
1021 {
1022     type_register_static(&arm_linux_boot_if_info);
1023 }
1024 
1025 type_init(arm_linux_boot_register_types)
1026