x20090325-1554

1 files changed, 150 insertions, 0 deletions

diff --git a/emu/port/devroot.c b/emu/port/devroot.c
new file mode 100644
index 00000000..695d151c
--- /dev/null
+++ b/emu/port/devroot.c
@@ -0,0 +1,150 @@
+#include	"dat.h"
+#include	"fns.h"
+#include	"error.h"
+
+extern Rootdata rootdata[];
+extern Dirtab roottab[];
+extern int	rootmaxq;
+
+static Chan*
+rootattach(char *spec)
+{
+	int i;
+	ulong len;
+	Rootdata *r;
+
+	if(*spec)
+		error(Ebadspec);
+	for (i = 0; i < rootmaxq; i++){
+		r = &rootdata[i];
+		if (r->sizep){
+			len = *r->sizep;
+			r->size = len;
+			roottab[i].length = len;
+		}
+	}
+	return devattach('/', spec);
+}
+
+static int
+rootgen(Chan *c, char *name, Dirtab *tab, int nd, int s, Dir *dp)
+{
+	int p, i;
+	Rootdata *r;
+
+	if(s == DEVDOTDOT){
+		p = rootdata[c->qid.path].dotdot;
+		c->qid.path = p;
+		c->qid.type = QTDIR;
+		name = "#/";
+		if(p != 0){
+			for(i = 0; i < rootmaxq; i++)
+				if(roottab[i].qid.path == c->qid.path){
+					name = roottab[i].name;
+					break;
+				}
+		}
+		devdir(c, c->qid, name, 0, eve, 0555, dp);
+		return 1;
+	}
+	if(name != nil){
+		isdir(c);
+		r = &rootdata[(int)c->qid.path];
+		tab = r->ptr;
+		for(i=0; i<r->size; i++, tab++)
+			if(strcmp(tab->name, name) == 0){
+				devdir(c, tab->qid, tab->name, tab->length, eve, tab->perm, dp);
+				return 1;
+			}
+		return -1;
+	}
+	if(s >= nd)
+		return -1;
+	tab += s;
+	devdir(c, tab->qid, tab->name, tab->length, eve, tab->perm, dp);
+	return 1;
+}
+
+static Walkqid*
+rootwalk(Chan *c, Chan *nc, char **name, int nname)
+{
+	ulong p;
+
+	p = c->qid.path;
+	if(nname == 0)
+		p = rootdata[p].dotdot;
+	return devwalk(c, nc, name, nname, rootdata[p].ptr, rootdata[p].size, rootgen);
+}
+
+static int
+rootstat(Chan *c, uchar *dp, int n)
+{
+	int p;
+
+	p = rootdata[c->qid.path].dotdot;
+	return devstat(c, dp, n, rootdata[p].ptr, rootdata[p].size, rootgen);
+}
+
+static Chan*
+rootopen(Chan *c, int omode)
+{
+	int p;
+
+	p = rootdata[c->qid.path].dotdot;
+	return devopen(c, omode, rootdata[p].ptr, rootdata[p].size, rootgen);
+}
+
+/*
+ * sysremove() knows this is a nop
+ */
+static void	 
+rootclose(Chan *c)
+{
+	USED(c);
+}
+
+static long	 
+rootread(Chan *c, void *buf, long n, vlong offset)
+{
+	ulong p, len;
+	uchar *data;
+
+	p = c->qid.path;
+	if(c->qid.type & QTDIR)
+		return devdirread(c, buf, n, rootdata[p].ptr, rootdata[p].size, rootgen);
+	len = rootdata[p].size;
+	if(offset < 0 || offset >= len)
+		return 0;
+	if(offset+n > len)
+		n = len - offset;
+	data = rootdata[p].ptr;
+	memmove(buf, data+offset, n);
+	return n;
+}
+
+static long	 
+rootwrite(Chan *c, void *a, long n, vlong off)
+{
+	USED(c); USED(a); USED(n); USED(off);
+	error(Eperm);
+	return 0;
+}
+
+Dev rootdevtab = {
+	'/',
+	"root",
+
+	devinit,
+	rootattach,
+	rootwalk,
+	rootstat,
+	rootopen,
+	devcreate,
+	rootclose,
+	rootread,
+	devbread,
+	rootwrite,
+	devbwrite,
+	devremove,
+	devwstat,
+};