#include	"u.h"
#include	"lib.h"
#include	"mem.h"
#include	"dat.h"
#include	"fns.h"
#include	"errno.h"
#include	"devtab.h"

enum{
	Qdir,
	Qbin,
	Qboot,
	Qcfs,
	Qdev,
	Qenv,
	Qproc,
};

extern long	cfslen;
extern ulong	*cfscode;


Dirtab rootdir[]={
	"bin",		{Qbin|CHDIR},	0,			0700,
	"boot",		{Qboot},	0,			0700,
	"dev",		{Qdev|CHDIR},	0,			0700,
	"env",		{Qenv|CHDIR},	0,			0700,
	"proc",		{Qproc|CHDIR},	0,			0700,
	"cfs",		{Qcfs},		0,			0700,
};

#define	NROOT	(sizeof rootdir/sizeof(Dirtab))
int	nroot;

void
rootreset(void)
{
	nroot = (cfslen > 0) ? NROOT : NROOT-1;
}

void
rootinit(void)
{
}

Chan*
rootattach(char *spec)
{
	return devattach('/', spec);
}

Chan*
rootclone(Chan *c, Chan *nc)
{
	return devclone(c, nc);
}

int	 
rootwalk(Chan *c, char *name)
{
	return devwalk(c, name, rootdir, nroot, devgen);
}

void	 
rootstat(Chan *c, char *dp)
{
	devstat(c, dp, rootdir, nroot, devgen);
}

Chan*
rootopen(Chan *c, int omode)
{
	return devopen(c, omode, rootdir, nroot, devgen);
}

void	 
rootcreate(Chan *c, char *name, int omode, ulong perm)
{
	error(Eperm);
}

/*
 * sysremove() knows this is a nop
 */
void	 
rootclose(Chan *c)
{
}

#include	"boot.h"

long	 
rootread(Chan *c, void *buf, long n)
{

	switch(c->qid.path & ~CHDIR){
	case Qdir:
		return devdirread(c, buf, n, rootdir, nroot, devgen);

	case Qboot:		/* boot */
		if(c->offset >= sizeof bootcode)
			return 0;
		if(c->offset+n > sizeof bootcode)
			n = sizeof bootcode - c->offset;
		memcpy(buf, ((char*)bootcode)+c->offset, n);
		return n;

	case Qcfs:		/* boot */
		if(c->offset >= cfslen)
			return 0;
		if(c->offset+n > cfslen)
			n = cfslen - c->offset;
		memcpy(buf, ((char*)cfscode)+c->offset, n);
		return n;

	case Qdev:
		return 0;
	}
	error(Egreg);
	return 0;
}

long	 
rootwrite(Chan *c, void *buf, long n)
{
	error(Egreg);
}

void	 
rootremove(Chan *c)
{
	error(Eperm);
}

void	 
rootwstat(Chan *c, char *dp)
{
	error(Eperm);
}