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fdt_machdep.c revision 1.37
      1 /* $NetBSD: fdt_machdep.c,v 1.37 2018/09/16 11:24:29 skrll Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2015-2017 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: fdt_machdep.c,v 1.37 2018/09/16 11:24:29 skrll Exp $");
     31 
     32 #include "opt_machdep.h"
     33 #include "opt_bootconfig.h"
     34 #include "opt_ddb.h"
     35 #include "opt_md.h"
     36 #include "opt_arm_debug.h"
     37 #include "opt_multiprocessor.h"
     38 #include "opt_cpuoptions.h"
     39 
     40 #include "ukbd.h"
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/bus.h>
     45 #include <sys/atomic.h>
     46 #include <sys/cpu.h>
     47 #include <sys/device.h>
     48 #include <sys/exec.h>
     49 #include <sys/kernel.h>
     50 #include <sys/kmem.h>
     51 #include <sys/ksyms.h>
     52 #include <sys/msgbuf.h>
     53 #include <sys/proc.h>
     54 #include <sys/reboot.h>
     55 #include <sys/termios.h>
     56 #include <sys/extent.h>
     57 #include <sys/bootblock.h>
     58 #include <sys/disklabel.h>
     59 #include <sys/vnode.h>
     60 #include <sys/kauth.h>
     61 #include <sys/fcntl.h>
     62 #include <sys/md5.h>
     63 
     64 #include <dev/cons.h>
     65 #include <uvm/uvm_extern.h>
     66 
     67 #include <sys/conf.h>
     68 
     69 #include <machine/db_machdep.h>
     70 #include <ddb/db_sym.h>
     71 #include <ddb/db_extern.h>
     72 
     73 #include <machine/bootconfig.h>
     74 #include <arm/armreg.h>
     75 
     76 #include <arm/cpufunc.h>
     77 
     78 #include <evbarm/include/autoconf.h>
     79 #include <evbarm/fdt/machdep.h>
     80 #include <evbarm/fdt/platform.h>
     81 
     82 #include <arm/fdt/arm_fdtvar.h>
     83 
     84 #if NUKBD > 0
     85 #include <dev/usb/ukbdvar.h>
     86 #endif
     87 
     88 #ifdef MEMORY_DISK_DYNAMIC
     89 #include <dev/md.h>
     90 #endif
     91 
     92 #ifndef FDT_MAX_BOOT_STRING
     93 #define FDT_MAX_BOOT_STRING 1024
     94 #endif
     95 
     96 BootConfig bootconfig;
     97 char bootargs[FDT_MAX_BOOT_STRING] = "";
     98 char *boot_args = NULL;
     99 
    100 /* filled in before cleaning bss. keep in .data */
    101 u_long uboot_args[4] __attribute__((__section__(".data")));
    102 const uint8_t *fdt_addr_r __attribute__((__section__(".data")));
    103 
    104 static char fdt_memory_ext_storage[EXTENT_FIXED_STORAGE_SIZE(DRAM_BLOCKS)];
    105 static struct extent *fdt_memory_ext;
    106 
    107 static uint64_t initrd_start, initrd_end;
    108 
    109 #include <libfdt.h>
    110 #include <dev/fdt/fdtvar.h>
    111 #define FDT_BUF_SIZE	(256*1024)
    112 static uint8_t fdt_data[FDT_BUF_SIZE];
    113 
    114 extern char KERNEL_BASE_phys[];
    115 #define KERNEL_BASE_PHYS ((paddr_t)KERNEL_BASE_phys)
    116 
    117 static void fdt_update_stdout_path(void);
    118 static void fdt_device_register(device_t, void *);
    119 static void fdt_cpu_rootconf(void);
    120 static void fdt_reset(void);
    121 static void fdt_powerdown(void);
    122 
    123 static dev_type_cnputc(earlyconsputc);
    124 static dev_type_cngetc(earlyconsgetc);
    125 
    126 static struct consdev earlycons = {
    127 	.cn_putc = earlyconsputc,
    128 	.cn_getc = earlyconsgetc,
    129 	.cn_pollc = nullcnpollc,
    130 };
    131 
    132 static void
    133 fdt_putchar(char c)
    134 {
    135 	const struct arm_platform *plat = arm_fdt_platform();
    136 	if (plat && plat->ap_early_putchar) {
    137 		plat->ap_early_putchar(c);
    138 	}
    139 #ifdef EARLYCONS
    140 	else {
    141 #define PLATFORM_EARLY_PUTCHAR ___CONCAT(EARLYCONS, _platform_early_putchar)
    142 		void PLATFORM_EARLY_PUTCHAR(char);
    143 		PLATFORM_EARLY_PUTCHAR(c);
    144 	}
    145 #endif
    146 }
    147 
    148 static void
    149 earlyconsputc(dev_t dev, int c)
    150 {
    151 	fdt_putchar(c);
    152 }
    153 
    154 static int
    155 earlyconsgetc(dev_t dev)
    156 {
    157 	return 0;	/* XXX */
    158 }
    159 
    160 #ifdef VERBOSE_INIT_ARM
    161 #define VPRINTF(...)	printf(__VA_ARGS__)
    162 #else
    163 #define VPRINTF(...)	do { } while (/* CONSTCOND */ 0)
    164 #endif
    165 
    166 /*
    167  * ARM: Get the first physically contiguous region of memory.
    168  * ARM64: Get all of physical memory, including holes.
    169  */
    170 static void
    171 fdt_get_memory(uint64_t *pstart, uint64_t *pend)
    172 {
    173 	const int memory = OF_finddevice("/memory");
    174 	uint64_t cur_addr, cur_size;
    175 	int index;
    176 
    177 	/* Assume the first entry is the start of memory */
    178 	if (fdtbus_get_reg64(memory, 0, &cur_addr, &cur_size) != 0)
    179 		panic("Cannot determine memory size");
    180 
    181 	*pstart = cur_addr;
    182 	*pend = cur_addr + cur_size;
    183 
    184 	VPRINTF("FDT /memory [%d] @ 0x%" PRIx64 " size 0x%" PRIx64 "\n",
    185 	    0, *pstart, *pend - *pstart);
    186 
    187 	for (index = 1;
    188 	     fdtbus_get_reg64(memory, index, &cur_addr, &cur_size) == 0;
    189 	     index++) {
    190 		VPRINTF("FDT /memory [%d] @ 0x%" PRIx64 " size 0x%" PRIx64 "\n",
    191 		    index, cur_addr, cur_size);
    192 
    193 #ifdef __aarch64__
    194 		if (cur_addr + cur_size > *pend)
    195 			*pend = cur_addr + cur_size;
    196 #else
    197 		/* If subsequent entries follow the previous, append them. */
    198 		if (*pend == cur_addr)
    199 			*pend = cur_addr + cur_size;
    200 #endif
    201 	}
    202 }
    203 
    204 void
    205 fdt_add_reserved_memory_range(uint64_t addr, uint64_t size)
    206 {
    207 	uint64_t start = trunc_page(addr);
    208 	uint64_t end = round_page(addr + size);
    209 
    210 	int error = extent_free(fdt_memory_ext, start,
    211 	     end - start, EX_NOWAIT);
    212 	if (error != 0)
    213 		printf("MEM ERROR: res %" PRIx64 "-%" PRIx64 " failed: %d\n",
    214 		    start, end, error);
    215 	else
    216 		VPRINTF("MEM: res %" PRIx64 "-%" PRIx64 "\n", start, end);
    217 }
    218 
    219 /*
    220  * Exclude memory ranges from memory config from the device tree
    221  */
    222 static void
    223 fdt_add_reserved_memory(uint64_t min_addr, uint64_t max_addr)
    224 {
    225 	uint64_t addr, size;
    226 	int index, error;
    227 
    228 	const int num = fdt_num_mem_rsv(fdtbus_get_data());
    229 	for (index = 0; index <= num; index++) {
    230 		error = fdt_get_mem_rsv(fdtbus_get_data(), index,
    231 		    &addr, &size);
    232 		if (error != 0 || size == 0)
    233 			continue;
    234 		if (addr + size <= min_addr)
    235 			continue;
    236 		if (addr >= max_addr)
    237 			continue;
    238 		if (addr < min_addr) {
    239 			size -= (min_addr - addr);
    240 			addr = min_addr;
    241 		}
    242 		if (addr + size > max_addr)
    243 			size = max_addr - addr;
    244 		fdt_add_reserved_memory_range(addr, size);
    245 	}
    246 }
    247 
    248 /*
    249  * Define usable memory regions.
    250  */
    251 static void
    252 fdt_build_bootconfig(uint64_t mem_start, uint64_t mem_end)
    253 {
    254 	const int memory = OF_finddevice("/memory");
    255 	BootConfig *bc = &bootconfig;
    256 	struct extent_region *er;
    257 	uint64_t addr, size;
    258 	int index, error;
    259 
    260 	fdt_memory_ext = extent_create("FDT Memory", mem_start, mem_end,
    261 	    fdt_memory_ext_storage, sizeof(fdt_memory_ext_storage), EX_EARLY);
    262 
    263 	for (index = 0;
    264 	     fdtbus_get_reg64(memory, index, &addr, &size) == 0;
    265 	     index++) {
    266 		if (addr >= mem_end || size == 0)
    267 			continue;
    268 		if (addr + size > mem_end)
    269 			size = mem_end - addr;
    270 
    271 		error = extent_alloc_region(fdt_memory_ext, addr, size,
    272 		    EX_NOWAIT);
    273 		if (error != 0)
    274 			printf("MEM ERROR: add %" PRIx64 "-%" PRIx64 " failed: %d\n",
    275 			    addr, addr + size, error);
    276 		VPRINTF("MEM: add %" PRIx64 "-%" PRIx64 "\n", addr, addr + size);
    277 	}
    278 
    279 	fdt_add_reserved_memory(mem_start, mem_end);
    280 
    281 	const uint64_t initrd_size = initrd_end - initrd_start;
    282 	if (initrd_size > 0)
    283 		fdt_add_reserved_memory_range(initrd_start, initrd_size);
    284 
    285 	VPRINTF("Usable memory:\n");
    286 	bc->dramblocks = 0;
    287 	LIST_FOREACH(er, &fdt_memory_ext->ex_regions, er_link) {
    288 		VPRINTF("  %lx - %lx\n", er->er_start, er->er_end);
    289 		bc->dram[bc->dramblocks].address = er->er_start;
    290 		bc->dram[bc->dramblocks].pages =
    291 		    (er->er_end - er->er_start) / PAGE_SIZE;
    292 		bc->dramblocks++;
    293 	}
    294 }
    295 
    296 static void
    297 fdt_probe_initrd(uint64_t *pstart, uint64_t *pend)
    298 {
    299 	*pstart = *pend = 0;
    300 
    301 #ifdef MEMORY_DISK_DYNAMIC
    302 	const int chosen = OF_finddevice("/chosen");
    303 	if (chosen < 0)
    304 		return;
    305 
    306 	int len;
    307 	const void *start_data = fdtbus_get_prop(chosen,
    308 	    "linux,initrd-start", &len);
    309 	const void *end_data = fdtbus_get_prop(chosen,
    310 	    "linux,initrd-end", NULL);
    311 	if (start_data == NULL || end_data == NULL)
    312 		return;
    313 
    314 	switch (len) {
    315 	case 4:
    316 		*pstart = be32dec(start_data);
    317 		*pend = be32dec(end_data);
    318 		break;
    319 	case 8:
    320 		*pstart = be64dec(start_data);
    321 		*pend = be64dec(end_data);
    322 		break;
    323 	default:
    324 		printf("Unsupported len %d for /chosen/initrd-start\n", len);
    325 		return;
    326 	}
    327 #endif
    328 }
    329 
    330 static void
    331 fdt_setup_initrd(void)
    332 {
    333 #ifdef MEMORY_DISK_DYNAMIC
    334 	const uint64_t initrd_size = initrd_end - initrd_start;
    335 	paddr_t startpa = trunc_page(initrd_start);
    336 	paddr_t endpa = round_page(initrd_end);
    337 	paddr_t pa;
    338 	vaddr_t va;
    339 	void *md_start;
    340 
    341 	if (initrd_size == 0)
    342 		return;
    343 
    344 	va = uvm_km_alloc(kernel_map, initrd_size, 0,
    345 	    UVM_KMF_VAONLY | UVM_KMF_NOWAIT);
    346 	if (va == 0) {
    347 		printf("Failed to allocate VA for initrd\n");
    348 		return;
    349 	}
    350 
    351 	md_start = (void *)va;
    352 
    353 	for (pa = startpa; pa < endpa; pa += PAGE_SIZE, va += PAGE_SIZE)
    354 		pmap_kenter_pa(va, pa, VM_PROT_READ|VM_PROT_WRITE, 0);
    355 	pmap_update(pmap_kernel());
    356 
    357 	md_root_setconf(md_start, initrd_size);
    358 #endif
    359 }
    360 
    361 u_int initarm(void *arg);
    362 
    363 u_int
    364 initarm(void *arg)
    365 {
    366 	const struct arm_platform *plat;
    367 	uint64_t memory_start, memory_end;
    368 
    369 	/* set temporally to work printf()/panic() even before consinit() */
    370 	cn_tab = &earlycons;
    371 
    372 	/* Load FDT */
    373 	int error = fdt_check_header(fdt_addr_r);
    374 	if (error == 0) {
    375 		error = fdt_move(fdt_addr_r, fdt_data, sizeof(fdt_data));
    376 		if (error != 0)
    377 			panic("fdt_move failed: %s", fdt_strerror(error));
    378 		fdtbus_set_data(fdt_data);
    379 	} else {
    380 		panic("fdt_check_header failed: %s", fdt_strerror(error));
    381 	}
    382 
    383 	/* Lookup platform specific backend */
    384 	plat = arm_fdt_platform();
    385 	if (plat == NULL)
    386 		panic("Kernel does not support this device");
    387 
    388 	/* Early console may be available, announce ourselves. */
    389 	VPRINTF("FDT<%p>\n", fdt_addr_r);
    390 
    391 	const int chosen = OF_finddevice("/chosen");
    392 	if (chosen >= 0)
    393 		OF_getprop(chosen, "bootargs", bootargs, sizeof(bootargs));
    394 	boot_args = bootargs;
    395 
    396 	VPRINTF("devmap\n");
    397 	pmap_devmap_register(plat->ap_devmap());
    398 #ifdef __aarch64__
    399 	pmap_devmap_bootstrap(plat->ap_devmap());
    400 #endif
    401 
    402 	/* Heads up ... Setup the CPU / MMU / TLB functions. */
    403 	VPRINTF("cpufunc\n");
    404 	if (set_cpufuncs())
    405 		panic("cpu not recognized!");
    406 
    407 	VPRINTF("bootstrap\n");
    408 	plat->ap_bootstrap();
    409 
    410 	/*
    411 	 * If stdout-path is specified on the command line, override the
    412 	 * value in /chosen/stdout-path before initializing console.
    413 	 */
    414 	fdt_update_stdout_path();
    415 
    416 	VPRINTF("consinit ");
    417 	consinit();
    418 	VPRINTF("ok\n");
    419 
    420 	VPRINTF("uboot: args %#lx, %#lx, %#lx, %#lx\n",
    421 	    uboot_args[0], uboot_args[1], uboot_args[2], uboot_args[3]);
    422 
    423 	cpu_reset_address = fdt_reset;
    424 	cpu_powerdown_address = fdt_powerdown;
    425 	evbarm_device_register = fdt_device_register;
    426 	evbarm_cpu_rootconf = fdt_cpu_rootconf;
    427 
    428 	/* Talk to the user */
    429 	VPRINTF("\nNetBSD/evbarm (fdt) booting ...\n");
    430 
    431 #ifdef BOOT_ARGS
    432 	char mi_bootargs[] = BOOT_ARGS;
    433 	parse_mi_bootargs(mi_bootargs);
    434 #endif
    435 
    436 	fdt_get_memory(&memory_start, &memory_end);
    437 
    438 #if !defined(_LP64)
    439 	/* Cannot map memory above 4GB */
    440 	if (memory_end >= 0x100000000ULL)
    441 		memory_end = 0x100000000ULL - PAGE_SIZE;
    442 
    443 #endif
    444 	uint64_t memory_size = memory_end - memory_start;
    445 
    446 	/* Parse ramdisk info */
    447 	fdt_probe_initrd(&initrd_start, &initrd_end);
    448 
    449 	/*
    450 	 * Populate bootconfig structure for the benefit of
    451 	 * dodumpsys
    452 	 */
    453 	fdt_build_bootconfig(memory_start, memory_end);
    454 
    455 	/* Perform PT build and VM init */
    456 	cpu_kernel_vm_init(memory_start, memory_size);
    457 
    458 	VPRINTF("bootargs: %s\n", bootargs);
    459 
    460 	parse_mi_bootargs(boot_args);
    461 
    462 	#define MAX_PHYSMEM 64
    463 	static struct boot_physmem fdt_physmem[MAX_PHYSMEM];
    464 	int nfdt_physmem = 0;
    465 	struct extent_region *er;
    466 
    467 	LIST_FOREACH(er, &fdt_memory_ext->ex_regions, er_link) {
    468 		VPRINTF("  %lx - %lx\n", er->er_start, er->er_end);
    469 		struct boot_physmem *bp = &fdt_physmem[nfdt_physmem++];
    470 
    471 		KASSERT(nfdt_physmem <= MAX_PHYSMEM);
    472 		bp->bp_start = atop(er->er_start);
    473 		bp->bp_pages = atop(er->er_end - er->er_start);
    474 		bp->bp_freelist = VM_FREELIST_DEFAULT;
    475 
    476 #ifdef _LP64
    477 		if (er->er_end > 0x100000000)
    478 			bp->bp_freelist = VM_FREELIST_HIGHMEM;
    479 #endif
    480 
    481 #ifdef PMAP_NEED_ALLOC_POOLPAGE
    482 		if (atop(memory_size) > bp->bp_pages) {
    483 			arm_poolpage_vmfreelist = VM_FREELIST_DIRECTMAP;
    484 			bp->bp_freelist = VM_FREELIST_DIRECTMAP;
    485 		}
    486 #endif
    487 	}
    488 
    489 	return initarm_common(KERNEL_VM_BASE, KERNEL_VM_SIZE, fdt_physmem,
    490 	     nfdt_physmem);
    491 }
    492 
    493 static void
    494 fdt_update_stdout_path(void)
    495 {
    496 	char *stdout_path, *ep;
    497 	int stdout_path_len;
    498 	char buf[256];
    499 
    500 	const int chosen_off = fdt_path_offset(fdt_data, "/chosen");
    501 	if (chosen_off == -1)
    502 		return;
    503 
    504 	if (get_bootconf_option(boot_args, "stdout-path",
    505 	    BOOTOPT_TYPE_STRING, &stdout_path) == 0)
    506 		return;
    507 
    508 	ep = strchr(stdout_path, ' ');
    509 	stdout_path_len = ep ? (ep - stdout_path) : strlen(stdout_path);
    510 	if (stdout_path_len >= sizeof(buf))
    511 		return;
    512 
    513 	strncpy(buf, stdout_path, stdout_path_len);
    514 	buf[stdout_path_len] = '\0';
    515 	fdt_setprop(fdt_data, chosen_off, "stdout-path",
    516 	    buf, stdout_path_len + 1);
    517 }
    518 
    519 void
    520 consinit(void)
    521 {
    522 	static bool initialized = false;
    523 	const struct arm_platform *plat = arm_fdt_platform();
    524 	const struct fdt_console *cons = fdtbus_get_console();
    525 	struct fdt_attach_args faa;
    526 	u_int uart_freq = 0;
    527 
    528 	if (initialized || cons == NULL)
    529 		return;
    530 
    531 	plat->ap_init_attach_args(&faa);
    532 	faa.faa_phandle = fdtbus_get_stdout_phandle();
    533 
    534 	if (plat->ap_uart_freq != NULL)
    535 		uart_freq = plat->ap_uart_freq();
    536 
    537 	cons->consinit(&faa, uart_freq);
    538 
    539 #if NUKBD > 0
    540 	ukbd_cnattach();	/* allow USB keyboard to become console */
    541 #endif
    542 
    543 	initialized = true;
    544 }
    545 
    546 void
    547 delay(u_int us)
    548 {
    549 	const struct arm_platform *plat = arm_fdt_platform();
    550 
    551 	plat->ap_delay(us);
    552 }
    553 
    554 static void
    555 fdt_detect_root_device(device_t dev)
    556 {
    557 	struct mbr_sector mbr;
    558 	uint8_t buf[DEV_BSIZE];
    559 	uint8_t hash[16];
    560 	const uint8_t *rhash;
    561 	char rootarg[32];
    562 	struct vnode *vp;
    563 	MD5_CTX md5ctx;
    564 	int error, len;
    565 	size_t resid;
    566 	u_int part;
    567 
    568 	const int chosen = OF_finddevice("/chosen");
    569 	if (chosen < 0)
    570 		return;
    571 
    572 	if (of_hasprop(chosen, "netbsd,mbr") &&
    573 	    of_hasprop(chosen, "netbsd,partition")) {
    574 
    575 		/*
    576 		 * The bootloader has passed in a partition index and MD5 hash
    577 		 * of the MBR sector. Read the MBR of this device, calculate the
    578 		 * hash, and compare it with the value passed in.
    579 		 */
    580 		rhash = fdtbus_get_prop(chosen, "netbsd,mbr", &len);
    581 		if (rhash == NULL || len != 16)
    582 			return;
    583 		of_getprop_uint32(chosen, "netbsd,partition", &part);
    584 		if (part >= MAXPARTITIONS)
    585 			return;
    586 
    587 		vp = opendisk(dev);
    588 		if (!vp)
    589 			return;
    590 		error = vn_rdwr(UIO_READ, vp, buf, sizeof(buf), 0, UIO_SYSSPACE,
    591 		    0, NOCRED, &resid, NULL);
    592 		VOP_CLOSE(vp, FREAD, NOCRED);
    593 		vput(vp);
    594 
    595 		if (error != 0)
    596 			return;
    597 
    598 		memcpy(&mbr, buf, sizeof(mbr));
    599 		MD5Init(&md5ctx);
    600 		MD5Update(&md5ctx, (void *)&mbr, sizeof(mbr));
    601 		MD5Final(hash, &md5ctx);
    602 
    603 		if (memcmp(rhash, hash, 16) != 0)
    604 			return;
    605 
    606 		snprintf(rootarg, sizeof(rootarg), " root=%s%c", device_xname(dev), part + 'a');
    607 		strcat(boot_args, rootarg);
    608 	}
    609 }
    610 
    611 static void
    612 fdt_device_register(device_t self, void *aux)
    613 {
    614 	const struct arm_platform *plat = arm_fdt_platform();
    615 
    616 	if (device_is_a(self, "armfdt"))
    617 		fdt_setup_initrd();
    618 
    619 	if (plat && plat->ap_device_register)
    620 		plat->ap_device_register(self, aux);
    621 }
    622 
    623 static void
    624 fdt_cpu_rootconf(void)
    625 {
    626 	device_t dev;
    627 	deviter_t di;
    628 	char *ptr;
    629 
    630 	for (dev = deviter_first(&di, 0); dev; dev = deviter_next(&di)) {
    631 		if (device_class(dev) != DV_DISK)
    632 			continue;
    633 
    634 		if (get_bootconf_option(boot_args, "root", BOOTOPT_TYPE_STRING, &ptr) != 0)
    635 			break;
    636 
    637 		if (device_is_a(dev, "ld") || device_is_a(dev, "sd") || device_is_a(dev, "wd"))
    638 			fdt_detect_root_device(dev);
    639 	}
    640 	deviter_release(&di);
    641 }
    642 
    643 static void
    644 fdt_reset(void)
    645 {
    646 	const struct arm_platform *plat = arm_fdt_platform();
    647 
    648 	fdtbus_power_reset();
    649 
    650 	if (plat && plat->ap_reset)
    651 		plat->ap_reset();
    652 }
    653 
    654 static void
    655 fdt_powerdown(void)
    656 {
    657 	fdtbus_power_poweroff();
    658 }
    659