xref: /openbmc/qemu/hw/arm/boot.c (revision 14a650ec)
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 "sysemu/sysemu.h"
14 #include "hw/boards.h"
15 #include "hw/loader.h"
16 #include "elf.h"
17 #include "sysemu/device_tree.h"
18 #include "qemu/config-file.h"
19 
20 #define KERNEL_ARGS_ADDR 0x100
21 #define KERNEL_LOAD_ADDR 0x00010000
22 
23 /* The worlds second smallest bootloader.  Set r0-r2, then jump to kernel.  */
24 static uint32_t bootloader[] = {
25   0xe3a00000, /* mov     r0, #0 */
26   0xe59f1004, /* ldr     r1, [pc, #4] */
27   0xe59f2004, /* ldr     r2, [pc, #4] */
28   0xe59ff004, /* ldr     pc, [pc, #4] */
29   0, /* Board ID */
30   0, /* Address of kernel args.  Set by integratorcp_init.  */
31   0  /* Kernel entry point.  Set by integratorcp_init.  */
32 };
33 
34 /* Handling for secondary CPU boot in a multicore system.
35  * Unlike the uniprocessor/primary CPU boot, this is platform
36  * dependent. The default code here is based on the secondary
37  * CPU boot protocol used on realview/vexpress boards, with
38  * some parameterisation to increase its flexibility.
39  * QEMU platform models for which this code is not appropriate
40  * should override write_secondary_boot and secondary_cpu_reset_hook
41  * instead.
42  *
43  * This code enables the interrupt controllers for the secondary
44  * CPUs and then puts all the secondary CPUs into a loop waiting
45  * for an interprocessor interrupt and polling a configurable
46  * location for the kernel secondary CPU entry point.
47  */
48 #define DSB_INSN 0xf57ff04f
49 #define CP15_DSB_INSN 0xee070f9a /* mcr cp15, 0, r0, c7, c10, 4 */
50 
51 static uint32_t smpboot[] = {
52   0xe59f2028, /* ldr r2, gic_cpu_if */
53   0xe59f0028, /* ldr r0, startaddr */
54   0xe3a01001, /* mov r1, #1 */
55   0xe5821000, /* str r1, [r2] - set GICC_CTLR.Enable */
56   0xe3a010ff, /* mov r1, #0xff */
57   0xe5821004, /* str r1, [r2, 4] - set GIC_PMR.Priority to 0xff */
58   DSB_INSN,   /* dsb */
59   0xe320f003, /* wfi */
60   0xe5901000, /* ldr     r1, [r0] */
61   0xe1110001, /* tst     r1, r1 */
62   0x0afffffb, /* beq     <wfi> */
63   0xe12fff11, /* bx      r1 */
64   0,          /* gic_cpu_if: base address of GIC CPU interface */
65   0           /* bootreg: Boot register address is held here */
66 };
67 
68 static void default_write_secondary(ARMCPU *cpu,
69                                     const struct arm_boot_info *info)
70 {
71     int n;
72     smpboot[ARRAY_SIZE(smpboot) - 1] = info->smp_bootreg_addr;
73     smpboot[ARRAY_SIZE(smpboot) - 2] = info->gic_cpu_if_addr;
74     for (n = 0; n < ARRAY_SIZE(smpboot); n++) {
75         /* Replace DSB with the pre-v7 DSB if necessary. */
76         if (!arm_feature(&cpu->env, ARM_FEATURE_V7) &&
77             smpboot[n] == DSB_INSN) {
78             smpboot[n] = CP15_DSB_INSN;
79         }
80         smpboot[n] = tswap32(smpboot[n]);
81     }
82     rom_add_blob_fixed("smpboot", smpboot, sizeof(smpboot),
83                        info->smp_loader_start);
84 }
85 
86 static void default_reset_secondary(ARMCPU *cpu,
87                                     const struct arm_boot_info *info)
88 {
89     CPUARMState *env = &cpu->env;
90 
91     stl_phys_notdirty(info->smp_bootreg_addr, 0);
92     env->regs[15] = info->smp_loader_start;
93 }
94 
95 #define WRITE_WORD(p, value) do { \
96     stl_phys_notdirty(p, value);  \
97     p += 4;                       \
98 } while (0)
99 
100 static void set_kernel_args(const struct arm_boot_info *info)
101 {
102     int initrd_size = info->initrd_size;
103     hwaddr base = info->loader_start;
104     hwaddr p;
105 
106     p = base + KERNEL_ARGS_ADDR;
107     /* ATAG_CORE */
108     WRITE_WORD(p, 5);
109     WRITE_WORD(p, 0x54410001);
110     WRITE_WORD(p, 1);
111     WRITE_WORD(p, 0x1000);
112     WRITE_WORD(p, 0);
113     /* ATAG_MEM */
114     /* TODO: handle multiple chips on one ATAG list */
115     WRITE_WORD(p, 4);
116     WRITE_WORD(p, 0x54410002);
117     WRITE_WORD(p, info->ram_size);
118     WRITE_WORD(p, info->loader_start);
119     if (initrd_size) {
120         /* ATAG_INITRD2 */
121         WRITE_WORD(p, 4);
122         WRITE_WORD(p, 0x54420005);
123         WRITE_WORD(p, info->initrd_start);
124         WRITE_WORD(p, initrd_size);
125     }
126     if (info->kernel_cmdline && *info->kernel_cmdline) {
127         /* ATAG_CMDLINE */
128         int cmdline_size;
129 
130         cmdline_size = strlen(info->kernel_cmdline);
131         cpu_physical_memory_write(p + 8, info->kernel_cmdline,
132                                   cmdline_size + 1);
133         cmdline_size = (cmdline_size >> 2) + 1;
134         WRITE_WORD(p, cmdline_size + 2);
135         WRITE_WORD(p, 0x54410009);
136         p += cmdline_size * 4;
137     }
138     if (info->atag_board) {
139         /* ATAG_BOARD */
140         int atag_board_len;
141         uint8_t atag_board_buf[0x1000];
142 
143         atag_board_len = (info->atag_board(info, atag_board_buf) + 3) & ~3;
144         WRITE_WORD(p, (atag_board_len + 8) >> 2);
145         WRITE_WORD(p, 0x414f4d50);
146         cpu_physical_memory_write(p, atag_board_buf, atag_board_len);
147         p += atag_board_len;
148     }
149     /* ATAG_END */
150     WRITE_WORD(p, 0);
151     WRITE_WORD(p, 0);
152 }
153 
154 static void set_kernel_args_old(const struct arm_boot_info *info)
155 {
156     hwaddr p;
157     const char *s;
158     int initrd_size = info->initrd_size;
159     hwaddr base = info->loader_start;
160 
161     /* see linux/include/asm-arm/setup.h */
162     p = base + KERNEL_ARGS_ADDR;
163     /* page_size */
164     WRITE_WORD(p, 4096);
165     /* nr_pages */
166     WRITE_WORD(p, info->ram_size / 4096);
167     /* ramdisk_size */
168     WRITE_WORD(p, 0);
169 #define FLAG_READONLY	1
170 #define FLAG_RDLOAD	4
171 #define FLAG_RDPROMPT	8
172     /* flags */
173     WRITE_WORD(p, FLAG_READONLY | FLAG_RDLOAD | FLAG_RDPROMPT);
174     /* rootdev */
175     WRITE_WORD(p, (31 << 8) | 0);	/* /dev/mtdblock0 */
176     /* video_num_cols */
177     WRITE_WORD(p, 0);
178     /* video_num_rows */
179     WRITE_WORD(p, 0);
180     /* video_x */
181     WRITE_WORD(p, 0);
182     /* video_y */
183     WRITE_WORD(p, 0);
184     /* memc_control_reg */
185     WRITE_WORD(p, 0);
186     /* unsigned char sounddefault */
187     /* unsigned char adfsdrives */
188     /* unsigned char bytes_per_char_h */
189     /* unsigned char bytes_per_char_v */
190     WRITE_WORD(p, 0);
191     /* pages_in_bank[4] */
192     WRITE_WORD(p, 0);
193     WRITE_WORD(p, 0);
194     WRITE_WORD(p, 0);
195     WRITE_WORD(p, 0);
196     /* pages_in_vram */
197     WRITE_WORD(p, 0);
198     /* initrd_start */
199     if (initrd_size) {
200         WRITE_WORD(p, info->initrd_start);
201     } else {
202         WRITE_WORD(p, 0);
203     }
204     /* initrd_size */
205     WRITE_WORD(p, initrd_size);
206     /* rd_start */
207     WRITE_WORD(p, 0);
208     /* system_rev */
209     WRITE_WORD(p, 0);
210     /* system_serial_low */
211     WRITE_WORD(p, 0);
212     /* system_serial_high */
213     WRITE_WORD(p, 0);
214     /* mem_fclk_21285 */
215     WRITE_WORD(p, 0);
216     /* zero unused fields */
217     while (p < base + KERNEL_ARGS_ADDR + 256 + 1024) {
218         WRITE_WORD(p, 0);
219     }
220     s = info->kernel_cmdline;
221     if (s) {
222         cpu_physical_memory_write(p, s, strlen(s) + 1);
223     } else {
224         WRITE_WORD(p, 0);
225     }
226 }
227 
228 static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
229 {
230     void *fdt = NULL;
231     char *filename;
232     int size, rc;
233     uint32_t acells, scells;
234 
235     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
236     if (!filename) {
237         fprintf(stderr, "Couldn't open dtb file %s\n", binfo->dtb_filename);
238         goto fail;
239     }
240 
241     fdt = load_device_tree(filename, &size);
242     if (!fdt) {
243         fprintf(stderr, "Couldn't open dtb file %s\n", filename);
244         g_free(filename);
245         goto fail;
246     }
247     g_free(filename);
248 
249     acells = qemu_devtree_getprop_cell(fdt, "/", "#address-cells");
250     scells = qemu_devtree_getprop_cell(fdt, "/", "#size-cells");
251     if (acells == 0 || scells == 0) {
252         fprintf(stderr, "dtb file invalid (#address-cells or #size-cells 0)\n");
253         goto fail;
254     }
255 
256     if (scells < 2 && binfo->ram_size >= (1ULL << 32)) {
257         /* This is user error so deserves a friendlier error message
258          * than the failure of setprop_sized_cells would provide
259          */
260         fprintf(stderr, "qemu: dtb file not compatible with "
261                 "RAM size > 4GB\n");
262         goto fail;
263     }
264 
265     rc = qemu_devtree_setprop_sized_cells(fdt, "/memory", "reg",
266                                           acells, binfo->loader_start,
267                                           scells, binfo->ram_size);
268     if (rc < 0) {
269         fprintf(stderr, "couldn't set /memory/reg\n");
270         goto fail;
271     }
272 
273     if (binfo->kernel_cmdline && *binfo->kernel_cmdline) {
274         rc = qemu_devtree_setprop_string(fdt, "/chosen", "bootargs",
275                                           binfo->kernel_cmdline);
276         if (rc < 0) {
277             fprintf(stderr, "couldn't set /chosen/bootargs\n");
278             goto fail;
279         }
280     }
281 
282     if (binfo->initrd_size) {
283         rc = qemu_devtree_setprop_cell(fdt, "/chosen", "linux,initrd-start",
284                 binfo->initrd_start);
285         if (rc < 0) {
286             fprintf(stderr, "couldn't set /chosen/linux,initrd-start\n");
287             goto fail;
288         }
289 
290         rc = qemu_devtree_setprop_cell(fdt, "/chosen", "linux,initrd-end",
291                     binfo->initrd_start + binfo->initrd_size);
292         if (rc < 0) {
293             fprintf(stderr, "couldn't set /chosen/linux,initrd-end\n");
294             goto fail;
295         }
296     }
297 
298     if (binfo->modify_dtb) {
299         binfo->modify_dtb(binfo, fdt);
300     }
301 
302     qemu_devtree_dumpdtb(fdt, size);
303 
304     cpu_physical_memory_write(addr, fdt, size);
305 
306     g_free(fdt);
307 
308     return 0;
309 
310 fail:
311     g_free(fdt);
312     return -1;
313 }
314 
315 static void do_cpu_reset(void *opaque)
316 {
317     ARMCPU *cpu = opaque;
318     CPUARMState *env = &cpu->env;
319     const struct arm_boot_info *info = env->boot_info;
320 
321     cpu_reset(CPU(cpu));
322     if (info) {
323         if (!info->is_linux) {
324             /* Jump to the entry point.  */
325             env->regs[15] = info->entry & 0xfffffffe;
326             env->thumb = info->entry & 1;
327         } else {
328             if (CPU(cpu) == first_cpu) {
329                 env->regs[15] = info->loader_start;
330                 if (!info->dtb_filename) {
331                     if (old_param) {
332                         set_kernel_args_old(info);
333                     } else {
334                         set_kernel_args(info);
335                     }
336                 }
337             } else {
338                 info->secondary_cpu_reset_hook(cpu, info);
339             }
340         }
341     }
342 }
343 
344 void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
345 {
346     CPUState *cs = CPU(cpu);
347     int kernel_size;
348     int initrd_size;
349     int n;
350     int is_linux = 0;
351     uint64_t elf_entry;
352     hwaddr entry;
353     int big_endian;
354 
355     /* Load the kernel.  */
356     if (!info->kernel_filename) {
357         /* If no kernel specified, do nothing; we will start from address 0
358          * (typically a boot ROM image) in the same way as hardware.
359          */
360         return;
361     }
362 
363     info->dtb_filename = qemu_opt_get(qemu_get_machine_opts(), "dtb");
364 
365     if (!info->secondary_cpu_reset_hook) {
366         info->secondary_cpu_reset_hook = default_reset_secondary;
367     }
368     if (!info->write_secondary_boot) {
369         info->write_secondary_boot = default_write_secondary;
370     }
371 
372     if (info->nb_cpus == 0)
373         info->nb_cpus = 1;
374 
375 #ifdef TARGET_WORDS_BIGENDIAN
376     big_endian = 1;
377 #else
378     big_endian = 0;
379 #endif
380 
381     /* We want to put the initrd far enough into RAM that when the
382      * kernel is uncompressed it will not clobber the initrd. However
383      * on boards without much RAM we must ensure that we still leave
384      * enough room for a decent sized initrd, and on boards with large
385      * amounts of RAM we must avoid the initrd being so far up in RAM
386      * that it is outside lowmem and inaccessible to the kernel.
387      * So for boards with less  than 256MB of RAM we put the initrd
388      * halfway into RAM, and for boards with 256MB of RAM or more we put
389      * the initrd at 128MB.
390      */
391     info->initrd_start = info->loader_start +
392         MIN(info->ram_size / 2, 128 * 1024 * 1024);
393 
394     /* Assume that raw images are linux kernels, and ELF images are not.  */
395     kernel_size = load_elf(info->kernel_filename, NULL, NULL, &elf_entry,
396                            NULL, NULL, big_endian, ELF_MACHINE, 1);
397     entry = elf_entry;
398     if (kernel_size < 0) {
399         kernel_size = load_uimage(info->kernel_filename, &entry, NULL,
400                                   &is_linux);
401     }
402     if (kernel_size < 0) {
403         entry = info->loader_start + KERNEL_LOAD_ADDR;
404         kernel_size = load_image_targphys(info->kernel_filename, entry,
405                                           info->ram_size - KERNEL_LOAD_ADDR);
406         is_linux = 1;
407     }
408     if (kernel_size < 0) {
409         fprintf(stderr, "qemu: could not load kernel '%s'\n",
410                 info->kernel_filename);
411         exit(1);
412     }
413     info->entry = entry;
414     if (is_linux) {
415         if (info->initrd_filename) {
416             initrd_size = load_ramdisk(info->initrd_filename,
417                                        info->initrd_start,
418                                        info->ram_size -
419                                        info->initrd_start);
420             if (initrd_size < 0) {
421                 initrd_size = load_image_targphys(info->initrd_filename,
422                                                   info->initrd_start,
423                                                   info->ram_size -
424                                                   info->initrd_start);
425             }
426             if (initrd_size < 0) {
427                 fprintf(stderr, "qemu: could not load initrd '%s'\n",
428                         info->initrd_filename);
429                 exit(1);
430             }
431         } else {
432             initrd_size = 0;
433         }
434         info->initrd_size = initrd_size;
435 
436         bootloader[4] = info->board_id;
437 
438         /* for device tree boot, we pass the DTB directly in r2. Otherwise
439          * we point to the kernel args.
440          */
441         if (info->dtb_filename) {
442             /* Place the DTB after the initrd in memory. Note that some
443              * kernels will trash anything in the 4K page the initrd
444              * ends in, so make sure the DTB isn't caught up in that.
445              */
446             hwaddr dtb_start = QEMU_ALIGN_UP(info->initrd_start + initrd_size,
447                                              4096);
448             if (load_dtb(dtb_start, info)) {
449                 exit(1);
450             }
451             bootloader[5] = dtb_start;
452         } else {
453             bootloader[5] = info->loader_start + KERNEL_ARGS_ADDR;
454             if (info->ram_size >= (1ULL << 32)) {
455                 fprintf(stderr, "qemu: RAM size must be less than 4GB to boot"
456                         " Linux kernel using ATAGS (try passing a device tree"
457                         " using -dtb)\n");
458                 exit(1);
459             }
460         }
461         bootloader[6] = entry;
462         for (n = 0; n < sizeof(bootloader) / 4; n++) {
463             bootloader[n] = tswap32(bootloader[n]);
464         }
465         rom_add_blob_fixed("bootloader", bootloader, sizeof(bootloader),
466                            info->loader_start);
467         if (info->nb_cpus > 1) {
468             info->write_secondary_boot(cpu, info);
469         }
470     }
471     info->is_linux = is_linux;
472 
473     for (; cs; cs = CPU_NEXT(cs)) {
474         cpu = ARM_CPU(cs);
475         cpu->env.boot_info = info;
476         qemu_register_reset(do_cpu_reset, cpu);
477     }
478 }
479