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      1 /*	$NetBSD: machdep.c,v 1.20 2024/03/05 14:15:29 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988 University of Utah.
      5  * Copyright (c) 1992, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * This code is derived from software contributed to Berkeley by
      9  * the Systems Programming Group of the University of Utah Computer
     10  * Science Department, The Mach Operating System project at
     11  * Carnegie-Mellon University and Ralph Campbell.
     12  *
     13  * Redistribution and use in source and binary forms, with or without
     14  * modification, are permitted provided that the following conditions
     15  * are met:
     16  * 1. Redistributions of source code must retain the above copyright
     17  *    notice, this list of conditions and the following disclaimer.
     18  * 2. Redistributions in binary form must reproduce the above copyright
     19  *    notice, this list of conditions and the following disclaimer in the
     20  *    documentation and/or other materials provided with the distribution.
     21  * 3. Neither the name of the University nor the names of its contributors
     22  *    may be used to endorse or promote products derived from this software
     23  *    without specific prior written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     35  * SUCH DAMAGE.
     36  *
     37  *	@(#)machdep.c	8.3 (Berkeley) 1/12/94
     38  * 	from: Utah Hdr: machdep.c 1.63 91/04/24
     39  */
     40 
     41 #include <sys/cdefs.h>
     42 __KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.20 2024/03/05 14:15:29 thorpej Exp $");
     43 
     44 #include "opt_ddb.h"
     45 
     46 #include <sys/param.h>
     47 #include <sys/systm.h>
     48 #include <sys/extent.h>
     49 #include <sys/kernel.h>
     50 #include <sys/buf.h>
     51 #include <sys/mbuf.h>
     52 #include <sys/reboot.h>
     53 #include <sys/mount.h>
     54 #include <sys/kcore.h>
     55 #include <sys/boot_flag.h>
     56 #include <sys/ksyms.h>
     57 #include <sys/proc.h>
     58 #include <sys/device.h>
     59 #include <sys/cpu.h>
     60 
     61 #include <uvm/uvm_extern.h>
     62 
     63 #include <dev/cons.h>
     64 
     65 #include <ufs/mfs/mfs_extern.h>		/* mfs_initminiroot() */
     66 
     67 #include <mips/cache.h>
     68 #include <machine/psl.h>
     69 #include <machine/autoconf.h>
     70 #include <emips/stand/common/prom_iface.h>
     71 #include <machine/sysconf.h>
     72 #include <machine/bootinfo.h>
     73 #include <machine/locore.h>
     74 #include <emips/emips/machdep.h>
     75 #include <machine/emipsreg.h>
     76 
     77 #define _EMIPS_BUS_DMA_PRIVATE
     78 #include <machine/bus.h>
     79 
     80 #if NKSYMS || defined(DDB) || defined(MODULAR)
     81 #include <machine/db_machdep.h>
     82 #include <ddb/db_extern.h>
     83 #endif
     84 
     85 vaddr_t iospace;
     86 vsize_t iospace_size = 64 * 1024; /* BUGBUG make it an option? */
     87 
     88 #include "ksyms.h"
     89 
     90 /*
     91  * Extent map to manage I/O register space.  We allocate storage for
     92  * 32 regions in the map.  iomap_ex_malloc_safe will indicate that it's
     93  * safe to use malloc() to dynamically allocate region descriptors in
     94  * case we run out.
     95  */
     96 static long iomap_ex_storage[EXTENT_FIXED_STORAGE_SIZE(32) / sizeof(long)];
     97 static struct extent *iomap_ex;
     98 static int iomap_ex_malloc_safe;
     99 
    100 /* maps for VM objects */
    101 struct vm_map *phys_map = NULL;
    102 
    103 int		systype;		    /* mother board type */
    104 char   *bootinfo = NULL;	/* pointer to bootinfo structure */
    105 int		cpuspeed = 30;		/* approx # instr per usec. */
    106 intptr_t	physmem_boardmax;	/* {model,SIMM}-specific bound on physmem */
    107 int		mem_cluster_cnt;
    108 phys_ram_seg_t	mem_clusters[VM_PHYSSEG_MAX];
    109 
    110 void	mach_init (int, char *[], int, intptr_t, u_int, char *); /* XXX */
    111 
    112 /* Motherboard or system-specific initialization vector */
    113 static void	unimpl_bus_reset(void);
    114 static void	unimpl_cons_init(void);
    115 static void	unimpl_iointr(uint32_t, vaddr_t, uint32_t);
    116 static void	unimpl_intr_establish(device_t, void *, int,
    117 		    int (*)(void *, void *), void *);
    118 static int	unimpl_memsize(void *);
    119 
    120 struct platform platform = {
    121 	"iobus not set",
    122 	unimpl_bus_reset,
    123 	unimpl_cons_init,
    124 	unimpl_iointr,
    125 	unimpl_intr_establish,
    126 	unimpl_memsize
    127 };
    128 
    129 extern char *esym;			/* XXX */
    130 extern struct consdev promcd;		/* XXX */
    131 extern const struct callback *callv;
    132 extern const struct callback callvec;
    133 
    134 /*
    135  * Do all the stuff that locore normally does before calling main().
    136  * The first 4 arguments are passed by PROM monitor, and remaining two
    137  * are built on temporary stack by our boot loader.
    138  */
    139 void
    140 mach_init(int argc, char *argv[], int code, intptr_t cv, u_int bim, char *bip)
    141 {
    142 	char *cp;
    143 	const char *bootinfo_msg;
    144 	u_long first, last;
    145 	int i, howtoboot;
    146 #if NKSYMS || defined(DDB) || defined(MODULAR)
    147 	void *ssym = 0;
    148 	struct btinfo_symtab *bi_syms;
    149 #endif
    150 	void *kernend;
    151 	extern char edata[], end[];	/* XXX */
    152 
    153 	/* Set up bootinfo structure looking at stack. */
    154 	if (bim == BOOTINFO_MAGIC) {
    155 		struct btinfo_magic *bi_magic;
    156 
    157 		bootinfo = bip;
    158 		bi_magic = lookup_bootinfo(BTINFO_MAGIC);
    159 		if (bi_magic == NULL || bi_magic->magic != BOOTINFO_MAGIC)
    160 			bootinfo_msg =
    161 			    "invalid magic number in bootinfo structure.\n";
    162 		else
    163 			bootinfo_msg = NULL;
    164 	} else
    165 		bootinfo_msg = "invalid bootinfo pointer (old bootblocks?)\n";
    166 
    167 	/*
    168 	 * Look at arguments passed to us and compute boothowto.
    169 	 * Do it before we decide to keep symbols.
    170 	 * NB: "boothowto" is in the BSS.
    171 	 */
    172 	howtoboot = 0;
    173 #ifdef KADB
    174 	howtoboot |= RB_KDB;
    175 #endif
    176 	for (i = 1; i < argc; i++) {
    177 		for (cp = argv[i]; *cp; cp++) {
    178 			switch (*cp) {
    179 
    180 #define RB_NOSYMBOLS 0x10000000
    181 			case 'e': /* empty the symtable */
    182 				howtoboot |= RB_NOSYMBOLS;
    183 				break;
    184 
    185 			case 'n': /* ask for names */
    186 				howtoboot |= RB_ASKNAME;
    187 				break;
    188 
    189 			case 'N': /* don't ask for names */
    190 				howtoboot &= ~RB_ASKNAME;
    191 				break;
    192 
    193 			default:
    194 				BOOT_FLAG(*cp, howtoboot); /* see sys/boot_flag.h */
    195 				break;
    196 			}
    197 		}
    198 	}
    199 
    200 	/* clear the BSS segment */
    201 #if NKSYMS || defined(DDB) || defined(MODULAR)
    202 	bi_syms = lookup_bootinfo(BTINFO_SYMTAB);
    203 
    204 	/* Was it a valid bootinfo symtab info? */
    205 	if ((bi_syms != NULL) && (!(howtoboot & RB_NOSYMBOLS))) {
    206 		ssym = (void *)(intptr_t)bi_syms->ssym;
    207 		esym = (void *)(intptr_t)bi_syms->esym;
    208 		kernend = (void *)mips_round_page(esym);
    209 		memset(edata, 0, end - edata);
    210 	} else
    211 #endif
    212 	{
    213 		kernend = (char *)mips_round_page(end);
    214 		/* should be done by bootloader? */
    215 		memset(edata, 0, (char *)kernend - (char *)edata);
    216 	}
    217 
    218 	/* Initialize callv so we can do PROM output... */
    219 	callv = (code == PROM_MAGIC) ? (void *)cv : &callvec;
    220 
    221 	/* Use PROM console output until we initialize a console driver. */
    222 	cn_tab = &promcd;
    223 
    224 #if 1
    225 	if (bootinfo_msg != NULL)
    226 		printf(bootinfo_msg);
    227 #endif
    228 	uvm_md_init();
    229 
    230 	/*
    231 	 * Copy exception-dispatch code down to exception vector.
    232 	 * Initialize locore-function vector.
    233 	 * Clear out the I and D caches.
    234 	 */
    235 	mips_vector_init(NULL, false);
    236 
    237 	/*
    238 	 * We know the CPU type now.  Initialize our DMA tags (might
    239 	 * need this early, for certain types of console devices!!).
    240 	 */
    241 	emips_bus_dma_init();
    242 
    243 	/* Look at argv[0] and compute bootdev */
    244 	makebootdev(argv[0]);
    245 
    246 	boothowto = howtoboot & ~RB_NOSYMBOLS;
    247 
    248 	/*
    249 	 * Check to see if a mini-root was loaded into memory. It resides
    250 	 * at the start of the next page just after the end of BSS.
    251 	 */
    252 	if (boothowto & RB_MINIROOT)
    253 		kernend = (char *)kernend
    254 		    + round_page(mfs_initminiroot(kernend));
    255 
    256 #if NKSYMS || defined(DDB) || defined(MODULAR)
    257 	/* init symbols if present */
    258 	if (esym) {
    259 		ksyms_addsyms_elf((char *)esym - (char *)ssym, ssym, esym);
    260 	}
    261 #endif
    262 #ifdef DDB
    263 	if (boothowto & RB_KDB)
    264 		Debugger();
    265 #endif
    266 
    267 	/*
    268 	 * Initialize physmem_boardmax; assume no SIMM-bank limits.
    269 	 * Adjust later in model-specific code if necessary.
    270 	 */
    271 	physmem_boardmax = MIPS_MAX_MEM_ADDR;
    272 
    273 	/*
    274 	 * Determine what model of computer we are running on.
    275 	 */
    276 	systype = ((prom_systype() >> 16) & 0xff);
    277 	if (systype >= nsysinit) {
    278 		platform_not_supported();
    279 		/* NOTREACHED */
    280 	}
    281 
    282 	/* Machine specific initialization. */
    283 	(*sysinit[systype].init)();
    284 
    285 	/* Find out how much memory is available. */
    286 	physmem = (*platform.memsize)(kernend);
    287 
    288 	/*
    289 	 * Load the rest of the available pages into the VM system.
    290 	 * NB: The kernel can span multiple segments.
    291 	 */
    292 	for (i = 0, physmem = 0; i < mem_cluster_cnt; ++i) {
    293 		first = mem_clusters[i].start;
    294 		if (first < round_page(MIPS_KSEG0_TO_PHYS(kernend)))
    295 			first = round_page(MIPS_KSEG0_TO_PHYS(kernend));
    296 		last = mem_clusters[i].start + mem_clusters[i].size;
    297 		physmem += atop(mem_clusters[i].size);
    298 
    299 		/* if the kernel spans multiple segments (does on ML40x) */
    300 		if (last <= first)
    301 			continue;
    302 
    303 		uvm_page_physload(atop(first), atop(last), atop(first),
    304 		    atop(last), VM_FREELIST_DEFAULT);
    305 	}
    306 
    307 	/*
    308 	 * Initialize error message buffer (at end of core).
    309 	 */
    310 	mips_init_msgbuf();
    311 
    312 	/*
    313 	 * Initialize the virtual memory system.
    314 	 */
    315 	iospace = pmap_limits.virtual_start;
    316 	pmap_limits.virtual_start += iospace_size;
    317 	pmap_bootstrap();
    318 
    319 	mips_init_lwp0_uarea();
    320 }
    321 
    322 void
    323 mips_machdep_cache_config(void)
    324 {
    325 }
    326 
    327 void
    328 consinit(void)
    329 {
    330 	/*
    331 	 * Init I/O memory extent map. Must be done before cninit()
    332 	 * is called; we may want to use iospace in the console routines.
    333 	 */
    334 	KASSERT(iospace != 0);
    335 	iomap_ex = extent_create("iomap", iospace,
    336 	    iospace + iospace_size - 1,
    337 	    (void *) iomap_ex_storage, sizeof(iomap_ex_storage),
    338 	    EX_NOCOALESCE|EX_NOWAIT);
    339 
    340 	/*
    341 	 * Up until now we have kept the TLB disabled,
    342 	 * and that allowed the "PROM" to work.
    343 	 * Specifically, romputc() and the debugger's getc() functions worked.
    344 	 * Now is the last chance we get to turn it on.
    345 	 * That means no more console I/O until autoconf() [sigh!], or..
    346 	 * The platform-specific code will have to map [1:1 probably]
    347 	 * the I/O registers.
    348 	 */
    349 	register_t s = mips_cp0_status_read();
    350 	s &= ~MIPS_SR_TS;
    351 	mips_cp0_status_write(s);
    352 
    353 	(*platform.cons_init)();
    354 
    355 	/*
    356 	 * Do NOT call cninit(); It will clobber cn_tab using constab[]
    357 	 * which we do not use
    358 	 */
    359 }
    360 
    361 /*
    362  * Allocates a virtual range suitable for mapping in physical memory.
    363  * Uses resource maps when allocating space, which is allocated from
    364  * the IOMAP submap. SIZE is a linear range (NOT vax-pages like the VAX).
    365  * If the page requested is bigger than a logical page, space is
    366  * allocated from the kernel map instead.
    367  */
    368 vaddr_t
    369 mips_map_physmem(paddr_t phys, vsize_t size)
    370 {
    371 	vaddr_t addr;
    372 	int error;
    373 	static int warned = 0;
    374 
    375 	size += phys & PAGE_MASK;
    376 	if (size >= PAGE_SIZE) {
    377 		addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_VAONLY);
    378 		if (addr == 0)
    379 			panic("mips_map_physmem: kernel map full");
    380 	} else {
    381 		error = extent_alloc(iomap_ex, size, PAGE_SIZE, 0,
    382 		    EX_FAST | EX_NOWAIT |
    383 		    (iomap_ex_malloc_safe ? EX_MALLOCOK : 0), (u_long *)&addr);
    384 		if (error) {
    385 			if (warned++ == 0) /* Warn only once */
    386 				printf("mips_map_physmem: iomap too small");
    387 			return 0;
    388 		}
    389 	}
    390 	ioaccess(addr, phys, size);
    391 #ifdef PHYSMEMDEBUG
    392 	printf("mips_map_physmem: alloc'ed %x bytes for paddr %x, at %x\n",
    393 	    size, phys, addr);
    394 #endif
    395 	return addr | (phys & PAGE_MASK);
    396 }
    397 
    398 /*
    399  * Unmaps the previous mapped (addr, size) pair.
    400  */
    401 void
    402 mips_unmap_physmem(vaddr_t addr, vsize_t size)
    403 {
    404 #ifdef PHYSMEMDEBUG
    405 	printf("mips_unmap_physmem: unmapping %x bytes at addr %x\n",
    406 	    size, addr);
    407 #endif
    408 	size += addr & PAGE_MASK;
    409 	addr &= ~PAGE_MASK;
    410 
    411 	iounaccess(addr, size);
    412 	if (size >= PAGE_SIZE)
    413 		uvm_km_free(kernel_map, addr, size, UVM_KMF_VAONLY);
    414 	else if (extent_free(iomap_ex, addr, size,
    415 	    EX_NOWAIT | (iomap_ex_malloc_safe ? EX_MALLOCOK : 0)))
    416 		printf("mips_unmap_physmem: addr 0x%llx size %llx: "
    417 		    "can't free region\n", (long long)addr, (long long)size);
    418 }
    419 
    420 /*
    421  * Machine-dependent startup code: allocate memory for variable-sized
    422  * tables.
    423  */
    424 void
    425 cpu_startup(void)
    426 {
    427 	vaddr_t minaddr, maxaddr;
    428 	char pbuf[9];
    429 #ifdef DEBUG
    430 	extern int pmapdebug;		/* XXX */
    431 	int opmapdebug = pmapdebug;
    432 
    433 	pmapdebug = 0;
    434 #endif
    435 
    436 	/*
    437 	 * Good {morning,afternoon,evening,night}.
    438 	 */
    439 	printf("%s%s", copyright, version);
    440 	printf("%s\n", cpu_getmodel());
    441 	format_bytes(pbuf, sizeof(pbuf), ctob(physmem));
    442 	printf("total memory = %s\n", pbuf);
    443 
    444 	minaddr = 0;
    445 
    446 	/*
    447 	 * Allocate a submap for physio
    448 	 */
    449 	phys_map = uvm_km_suballoc(kernel_map, &minaddr, &maxaddr,
    450 				   VM_PHYS_SIZE, 0, false, NULL);
    451 
    452 	/*
    453 	 * No need to allocate an mbuf cluster submap.  Mbuf clusters
    454 	 * are allocated via the pool allocator, and we use KSEG to
    455 	 * map those pages.
    456 	 */
    457 
    458 	iomap_ex_malloc_safe = 1;
    459 
    460 #ifdef DEBUG
    461 	pmapdebug = opmapdebug;
    462 #endif
    463 	format_bytes(pbuf, sizeof(pbuf), ptoa(uvm_availmem(false)));
    464 	printf("avail memory = %s\n", pbuf);
    465 }
    466 
    467 /*
    468  * Look up information in bootinfo of boot loader.
    469  */
    470 void *
    471 lookup_bootinfo(int type)
    472 {
    473 	struct btinfo_common *bt;
    474 	char *help = bootinfo;
    475 
    476 	/* Check for a bootinfo record first. */
    477 	if (help == NULL)
    478 		return (NULL);
    479 
    480 	do {
    481 		bt = (struct btinfo_common *)help;
    482 		if (bt->type == type)
    483 			return ((void *)help);
    484 		help += bt->next;
    485 	} while (bt->next != 0 &&
    486 		(size_t)help < (size_t)bootinfo + BOOTINFO_SIZE);
    487 
    488 	return (NULL);
    489 }
    490 
    491 void
    492 cpu_reboot(volatile int howto,	/* XXX volatile to keep gcc happy */
    493            char *bootstr)
    494 {
    495 
    496 	/* take a snap shot before clobbering any registers */
    497 	if (curlwp)
    498 		savectx(curpcb);
    499 
    500 #ifdef DEBUG
    501 	if (panicstr)
    502 		stacktrace();
    503 #endif
    504 
    505 	/* If system is cold, just halt. */
    506 	if (cold) {
    507 		howto |= RB_HALT;
    508 		goto haltsys;
    509 	}
    510 
    511 	/* If "always halt" was specified as a boot flag, obey. */
    512 	if ((boothowto & RB_HALT) != 0)
    513 		howto |= RB_HALT;
    514 
    515 	boothowto = howto;
    516 	if ((howto & RB_NOSYNC) == 0) {
    517 		/*
    518 		 * Synchronize the disks....
    519 		 */
    520 		vfs_shutdown();
    521 	}
    522 
    523 	/* Disable interrupts. */
    524 	splhigh();
    525 
    526 	/* If rebooting and a dump is requested do it. */
    527 	if ((howto & (RB_DUMP | RB_HALT)) == RB_DUMP)
    528 		dumpsys();
    529 
    530 haltsys:
    531 	/* run any shutdown hooks */
    532 	doshutdownhooks();
    533 
    534 	pmf_system_shutdown(boothowto);
    535 
    536 	/* Finally, halt/reboot the system. */
    537 	printf("%s\n\n", ((howto & RB_HALT) != 0) ? "halted." : "rebooting...");
    538 
    539 	prom_halt(howto);
    540 	for (;;) ;
    541 	/*NOTREACHED*/
    542 }
    543 
    544 #if defined(MIPS_4GB_PHYSICAL_MEMORY)
    545 #define trim_memory(n) n
    546 #else
    547 #if 0
    548 #define TOO_MUCH (MIPS_PHYS_MASK+1)
    549 #else
    550 #define TOO_MUCH (2*64*1024*1024)
    551 #endif
    552 u_long trim_memory(uint32_t nbytes);/*cheat*/
    553 u_long trim_memory(uint32_t nbytes)
    554 {
    555 	int i;
    556 	u_long first, last;
    557 
    558 	nbytes *= 4096;
    559 	if (nbytes <= TOO_MUCH)
    560 		return nbytes;
    561 
    562 	/* We have more memory than we can handle */
    563 
    564 	mem_clusters[mem_cluster_cnt].start = 0;/* sentinel record */
    565 	mem_clusters[mem_cluster_cnt].size = 0;
    566 	for (i = 0; i < mem_cluster_cnt;) {
    567 		first = mem_clusters[i].start;
    568 		last = mem_clusters[i].start + mem_clusters[i].size;
    569 
    570 		if (first > TOO_MUCH) {
    571 			printf("Too much memory, ignoring memory "
    572 			    "range %08lx..%08lx\n", first, last);
    573 			memcpy(mem_clusters+i,mem_clusters+i+1,
    574 			    (sizeof(mem_clusters[0])*(mem_cluster_cnt-i)));
    575 			mem_cluster_cnt--;
    576 			continue;
    577 		}
    578 
    579 		if (last > TOO_MUCH) {
    580 			last = TOO_MUCH;
    581 			printf("Too much memory in cluster %d, trimming "
    582 			   "memory to range %08lx..%08lx\n",
    583 			   i, first, last);
    584 			mem_clusters[i].size = last - mem_clusters[i].start;
    585 		}
    586 		i++;
    587 	}
    588 	return TOO_MUCH;
    589 }
    590 #endif
    591 
    592 /*
    593  * Find out how much memory is available by testing memory.
    594  */
    595 int
    596 memsize_scan(void *first)
    597 {
    598 	int i, mem;
    599 	char *cp;
    600 
    601 	mem = btoc((paddr_t)first - MIPS_KSEG0_START);
    602 	cp = (char *)MIPS_PHYS_TO_KSEG1(mem << PGSHIFT);
    603 	while (cp < (char *)physmem_boardmax) {
    604 	  	int j;
    605 		if (badaddr(cp, 4))
    606 			break;
    607 		i = *(int *)cp;
    608 		j = ((int *)cp)[4];
    609 		*(int *)cp = 0xa5a5a5a5;
    610 		/*
    611 		 * Data will persist on the bus if we read it right away.
    612 		 * Have to be tricky here.
    613 		 */
    614 		((int *)cp)[4] = 0x5a5a5a5a;
    615 		wbflush();
    616 		if (*(int *)cp != 0xa5a5a5a5)
    617 			break;
    618 		*(int *)cp = i;
    619 		((int *)cp)[4] = j;
    620 		cp += PAGE_SIZE;
    621 		mem++;
    622 	}
    623 
    624 	/*
    625 	 * Now that we know how much memory we have, initialize the
    626 	 * mem cluster array.
    627 	 */
    628 	mem_clusters[0].start = 0;		/* XXX is this correct? */
    629 	mem_clusters[0].size  = ctob(mem);
    630 	mem_cluster_cnt = 1;
    631 
    632 	/* clear any memory error conditions possibly caused by probe */
    633 	(*platform.bus_reset)();
    634 	return (mem);
    635 }
    636 
    637 /*
    638  * Find out how much memory is available by testing memory, starting at first.
    639  * Returns the total number of pages.
    640  */
    641 int
    642 memsize_pmt(void * first)
    643 {
    644 	int i, mem;
    645 	struct _Pmt *Pmt = ThePmt;
    646 	struct _Sram *ram;
    647 	uint32_t addr, len;
    648 
    649 	/*
    650 	 * Build the RAM memory map from the PMT.
    651 	 */
    652 	mem = 0;
    653 	for (i = 0; i < VM_PHYSSEG_MAX; Pmt--) {
    654 		uint16_t tag = Pmt->Tag;
    655 
    656 		if (tag == PMTTAG_END_OF_TABLE)
    657 			break;
    658 
    659 		if ((tag != PMTTAG_SRAM) && (tag != PMTTAG_DDRAM))
    660 			continue;
    661 
    662 		/*
    663 		 * Got a memory controller segment,
    664 		 * scan all the controllers in it
    665 		 */
    666 		ram = (struct _Sram *)(Pmt->TopOfPhysicalAddress << 16);
    667 
    668 		for (;(ram->BaseAddressAndTag & SRAMBT_TAG) == tag;) {
    669 			addr = ram->BaseAddressAndTag & SRAMBT_BASE;
    670 			len  = ram->Control & SRAMST_SIZE;
    671 
    672 			mem_clusters[i].start = addr;
    673 			mem_clusters[i].size  = len;
    674 			printf("memory segment %2d start %08lx size %08lx\n", i,
    675 			    (long)mem_clusters[i].start,
    676 			    (long)mem_clusters[i].size);
    677 			i++;
    678 			mem += len;
    679 
    680 			/* SRAM and DDRAM have different sizes */
    681 			ram = (tag == PMTTAG_SRAM) ? ram+1 : ram+2;
    682 		}
    683 	}
    684 	mem_cluster_cnt = i;
    685 
    686 	return trim_memory(btoc(mem));
    687 }
    688 /*
    689  *  Ensure all platform vectors are always initialized.
    690  */
    691 static void
    692 unimpl_bus_reset(void)
    693 {
    694 
    695 	panic("sysconf.init didn't set bus_reset");
    696 }
    697 
    698 static void
    699 unimpl_cons_init(void)
    700 {
    701 
    702 	panic("sysconf.init didn't set cons_init");
    703 }
    704 
    705 static void
    706 unimpl_iointr(uint32_t status, vaddr_t pc, uint32_t ipending)
    707 {
    708 
    709 	panic("sysconf.init didn't set intr");
    710 }
    711 
    712 static void
    713 unimpl_intr_establish(device_t dev, void *cookie, int level,
    714                       int (*handler) (void *,void *), void *arg)
    715 {
    716 
    717 	panic("sysconf.init didn't set intr_establish");
    718 }
    719 
    720 static int
    721 unimpl_memsize(void * first)
    722 {
    723 
    724 	panic("sysconf.init didn't set memsize");
    725 }
    726 
    727 /*
    728  * Wait "n" microseconds.
    729  */
    730 void
    731 delay(int n)
    732 {
    733 
    734 	DELAY(n);
    735 }
    736