#include	"u.h"#include	"mem.h"#include	"dat.h"#include	"fns.h"#include	"lib.h" static int	debug; enum {	Maxbank = 2,}; Bank	bank[Maxbank];int	nbank; voidmeminit(void){	Memdsc *mem;	Memclust *c;	int i;	uvlong npage, p0, p1;	extern ulong _main[], edata[]; 	mem = (Memdsc*)((ulong)hwrpb + hwrpb->memoff);	if (debug)		print("\nnumber of clusters: %lld\n", mem->nclust);	npage = 0;	conf.maxphys = 0;	for (i = 0; i < mem->nclust; i++) {		c = &mem->clust[i];		p0 = c->pfn*hwrpb->by2pg;		p1 = (c->pfn+c->npages)*hwrpb->by2pg;		if (debug) {			print("clust%d: %llux-%llux, tested %llud/%llud vabitm %llux usage %llux\n",				i, p0, p1, c->ntest, c->npages, c->vabitm, c->usage);			if (c->vabitm)				print("\tfirst 64 pages: %llux\n", *(uvlong*)c->vabitm);		}		npage += c->npages;		if (p1 > conf.maxphys)			conf.maxphys = p1;		switch ((ulong)c->usage&3) {		case 0:			if (nbank >= Maxbank) {				print("increase Maxbank; lost %lldMB\n", c->npages*hwrpb->by2pg/MB);				break;			}			bank[nbank].min = p0;			bank[nbank].max = p1;			nbank++;			break;		case 2:			print("nvram skipped\n");			break;		}	}	if (debug)		print("\n"); 	print("Memory size: %lludMB\n", npage*hwrpb->by2pg/MB);	print("\n"); 	/* kernel virtual space = 2G.  leave room for kmapio */	if (conf.maxphys > 1024*MB) {		print("meminit: too much physical memory; only first gigabyte mapped\n\n");		conf.maxphys = 1024*MB;	} 	conf.nbank = nbank;	conf.bank = bank;} intvalidrgn(ulong min, ulong max){	int i; 	min &= ~KZERO;	max &= ~KZERO;	for (i = 0; i < nbank; i++)		if (bank[i].min <= min && max <= bank[i].max)			return 1;	return 0;} uvlongallocate(int pages){	uvlong top, len;	int from, i; 	top = 0;	len = pages*hwrpb->by2pg;	from = -1;	for (i = 0; i < nbank; i++)		if (bank[i].max - bank[i].min >= len && bank[i].max > top) {			top = bank[i].max;			from = i;		}	if (from < 0)		return 0;	bank[from].max -= len;	conf.bank[from].max = bank[from].max;	for (i = 0; i < len>>3; i++)		stqp(bank[from].max+8*i, 0);	return bank[from].max;}