import xen 32 bit paravirtual kernel from /n/sources/xen.

1 files changed, 248 insertions, 0 deletions

diff --git a/sys/src/9/xen/dpart.c b/sys/src/9/xen/dpart.c
new file mode 100644
index 000000000..17d3e4a3a
--- /dev/null
+++ b/sys/src/9/xen/dpart.c
@@ -0,0 +1,248 @@
+#include <u.h>
+#include <libc.h>
+#include <disk.h>
+
+typedef void Fs;
+#include "/sys/src/boot/pc/dosfs.h"
+
+enum {
+	Npart = 32
+};
+
+#define	GSHORT(p)		(((p)[1]<<8)|(p)[0])
+#define	GLONG(p)			((GSHORT(p+2)<<16)|GSHORT(p))
+
+int
+readdisk(Disk *d, void *buf, vlong off, int len)
+{
+	if(seek(d->fd, off, 0) == -1
+	|| read(d->fd, buf, len) != len)
+		return -1;
+	return 0;
+}
+
+void
+addpart(Disk *d, char *name, ulong s, ulong e)
+{
+	print("%s: part %s %lud %lud\n", d->prefix, name, s, e);
+	fprint(d->ctlfd, "part %s %lud %lud\n", name, s, e);
+}
+
+int
+isdos(int t)
+{
+	return t==FAT12 || t==FAT16 || t==FATHUGE || t==FAT32 || t==FAT32X;
+}
+
+int
+isextend(int t)
+{
+	return t==EXTEND || t==EXTHUGE || t==LEXTEND;
+}
+
+
+
+/* build a cdboot partition if there is an embedded boot floppy image */
+int
+cdpart(Disk *d)
+{
+	uchar buf[2048];
+	ulong a, n;
+	uchar *p;
+
+	if(readdisk(d, buf, 17*2048, 2048) == -1
+	|| strcmp((char*)buf+1, "CD001\x01EL TORITO SPECIFICATION") != 0)
+		return 0;
+
+	p = buf + 0x47;
+	a = p[0] | (p[1]<<8) | (p[2]<<16) | (p[3]<<24);
+	
+	if(readdisk(d, buf, a*2048, 2048) == -1
+	|| memcmp((char*)buf, "\x01\x00\x00\x00", 4) != 0
+	|| memcmp((char*)buf+30, "\x55\xAA", 2) != 0
+	|| buf[0x20] != 0x88)
+		return 0;
+
+	p = buf+0x28;
+	a = p[0]|(p[1]<<8)|(p[2]<<16)|(p[3]<<24);
+
+	switch(buf[0x21]) {
+	case 1: n = 1200*1024; break;
+	case 2: n = 1440*1024; break;
+	case 3: n = 2880*1024; break;
+	default: return 0;
+	}
+
+	a = a * (uvlong)2048 / d->secsize;
+	n /= d->secsize;
+	addpart(d, "cdboot", a, a+n);
+	return 1;
+}
+
+int
+p9part(Disk *d, char *name, ulong pstart)
+{
+	char partbuf[512];
+	char *field[4], *line[Npart+1], *name2;
+	ulong start, end;
+	int i, n;
+
+	name2 = smprint("%s%s", d->prefix, name);
+	d = opendisk(name2, 1, 0);
+	if(!d) {
+		fprint(2, "%s: %r\n", name2);
+		free(name2);
+		return 0;
+	}
+	free(name2);
+
+	if(readdisk(d, partbuf, 512, sizeof partbuf) == -1)
+		return 0;
+	partbuf[sizeof partbuf - 1] = '\0';
+	if(strncmp(partbuf, "part ", 5) != 0
+	|| (n = getfields(partbuf, line, Npart+1, 0, "\n")) == 0)
+		return 0;
+	for(i = 0; i < n; i++) {
+		if(strncmp(line[i], "part ", 5) != 0)
+			break;
+		if(getfields(line[i], field, 4, 0, " ") != 4)
+			break;
+		start = strtoul(field[2], 0, 0);
+		end = strtoul(field[3], 0, 0);
+		if(start >= end)
+			break;
+		addpart(d, field[1], pstart+start, pstart+end);
+	}
+	return 0;
+}
+
+int
+mbrpart(Disk *d)
+{
+	uchar mbrbuf[512];
+	char name[10];
+	Dospart *dp;
+	ulong taboffset, start, end;
+	ulong firstxpart, nxtxpart;
+	int i, nplan9, havedos;
+
+#define readmbr()	\
+	if(readdisk(d, mbrbuf, (uvlong)taboffset*512, sizeof mbrbuf) == -1	\
+	|| mbrbuf[0x1FE] != 0x55 || mbrbuf[0x1FF] != 0xAA)	\
+		return 0
+
+	if(d->secsize > 512)
+		return 0;
+	dp = (Dospart*)&mbrbuf[0x1BE];
+	taboffset = 0;
+
+	if(1) {
+		/* get the MBR (allowing for DMDDO) */
+		readmbr();
+		for(i = 0; i < 4; i++) {
+			if(dp[i].type == DMDDO) {
+				taboffset = 63;
+				readmbr();
+				i = -1;		/* start over */
+			}
+		}
+	}
+
+	/*
+	 * Read the partitions, first from the MBR and then
+	 * from successive extended partition tables.
+	 */
+	nplan9 = 0;
+	havedos = 0;
+	firstxpart = 0;
+	for(;;) {
+		readmbr();
+		nxtxpart = 0;
+		for(i = 0; i < 4; i++) {
+			/* partition offsets are relative to taboffset */
+			start = taboffset+GLONG(dp[i].start);
+			end = start+GLONG(dp[i].len);
+			if(dp[i].type == PLAN9) {
+				if(nplan9 == 0)
+					strcpy(name, "plan9");
+				else
+					sprint(name, "plan9.%d", nplan9);
+				addpart(d, name, start, end);
+				p9part(d, name, start);
+				nplan9++;
+			}
+
+			if(!havedos && isdos(dp[i].type)) {
+				havedos = 1;
+				addpart(d, "dos", start, end);
+			}
+
+			/* nxtxpart is relative to firstxpart (or 0), not taboffset */
+			if(isextend(dp[i].type))
+				nxtxpart = start-taboffset+firstxpart;
+		}
+		if(!nxtxpart)
+			break;
+		if(!firstxpart)
+			firstxpart = nxtxpart;
+		taboffset = nxtxpart;
+	}
+	return nplan9 + havedos;
+}
+
+void
+partall(void)
+{
+	Disk *d;
+	Dir *ent;
+	char *name;
+	int fd, i, n;
+
+	fd = open("#S", OREAD);
+	if(fd == -1) {
+		fprint(2, "No disk\n");
+		return;
+	}
+
+	while((n = dirread(fd, &ent)) > 0) {
+		for(i = 0; i < n; i++) {
+			if(ent[i].mode & DMDIR) {
+				name = smprint("#S/%s/data", ent[i].name);
+				d = opendisk(name, 1, 0);
+				if(!d) {
+					fprint(2, "%s: %r\n", name);
+					continue;
+				}
+				// XXX not safe yet: if(!mbrpart(d) && !cdpart(d) && !p9part(d, "data", 0))
+				if(!mbrpart(d) && !cdpart(d))
+					fprint(2, "%s: no partitions\n", name);
+				close(d->fd);
+			}
+		}
+	}
+	close(fd);				
+}
+
+
+void
+main(int argc, char **argv)
+{
+	USED(argc, argv);
+
+	fmtinstall('r', errfmt);
+
+	bind("#c", "/dev", MBEFORE);
+	open("/dev/cons", OREAD);
+	open("/dev/cons", OWRITE);
+	open("/dev/cons", OWRITE);
+
+	partall();
+
+	close(0);
+	close(1);
+	close(2);
+
+	exec("/boot/boot2", argv);
+	
+	exits(0);
+}