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#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"
#include "io.h"
enum {
Qdir = 0,
Qbase,
Qmax = 16,
};
typedef long Rdwrfn(Chan*, void*, long, vlong);
static Rdwrfn *readfn[Qmax];
static Rdwrfn *writefn[Qmax];
static Dirtab archdir[Qmax] = {
".", { Qdir, 0, QTDIR }, 0, 0555,
};
Lock archwlock; /* the lock is only for changing archdir */
int narchdir = Qbase;
/*
* Add a file to the #P listing. Once added, you can't delete it.
* You can't add a file with the same name as one already there,
* and you get a pointer to the Dirtab entry so you can do things
* like change the Qid version. Changing the Qid path is disallowed.
*/
Dirtab*
addarchfile(char *name, int perm, Rdwrfn *rdfn, Rdwrfn *wrfn)
{
int i;
Dirtab d;
Dirtab *dp;
memset(&d, 0, sizeof d);
strcpy(d.name, name);
d.perm = perm;
lock(&archwlock);
if(narchdir >= Qmax){
unlock(&archwlock);
return nil;
}
for(i=0; i<narchdir; i++)
if(strcmp(archdir[i].name, name) == 0){
unlock(&archwlock);
return nil;
}
d.qid.path = narchdir;
archdir[narchdir] = d;
readfn[narchdir] = rdfn;
writefn[narchdir] = wrfn;
dp = &archdir[narchdir++];
unlock(&archwlock);
return dp;
}
static Chan*
archattach(char* spec)
{
return devattach('P', spec);
}
Walkqid*
archwalk(Chan* c, Chan *nc, char** name, int nname)
{
return devwalk(c, nc, name, nname, archdir, narchdir, devgen);
}
static int
archstat(Chan* c, uchar* dp, int n)
{
return devstat(c, dp, n, archdir, narchdir, devgen);
}
static Chan*
archopen(Chan* c, int omode)
{
return devopen(c, omode, archdir, narchdir, devgen);
}
static void
archclose(Chan*)
{
}
static long
archread(Chan *c, void *a, long n, vlong offset)
{
Rdwrfn *fn;
switch((ulong)c->qid.path){
case Qdir:
return devdirread(c, a, n, archdir, narchdir, devgen);
default:
if(c->qid.path < narchdir && (fn = readfn[c->qid.path]))
return fn(c, a, n, offset);
error(Eperm);
break;
}
return 0;
}
static long
archwrite(Chan *c, void *a, long n, vlong offset)
{
Rdwrfn *fn;
if(c->qid.path < narchdir && (fn = writefn[c->qid.path]))
return fn(c, a, n, offset);
error(Eperm);
return 0;
}
void archinit(void);
Dev archdevtab = {
'P',
"arch",
devreset,
archinit,
devshutdown,
archattach,
archwalk,
archstat,
archopen,
devcreate,
archclose,
archread,
devbread,
archwrite,
devbwrite,
devremove,
devwstat,
};
static long
cputyperead(Chan*, void *a, long n, vlong offset)
{
char str[128];
snprint(str, sizeof str, "ARM11 %d\n", m->cpumhz);
return readstr(offset, a, n, str);
}
void
archinit(void)
{
addarchfile("cputype", 0444, cputyperead, nil);
}
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