Import sources from 2011-03-30 iso image

1 files changed, 354 insertions, 0 deletions

diff --git a/sys/src/boot/pc/part.c b/sys/src/boot/pc/part.c
new file mode 100755
index 000000000..e7dfc72fc
--- /dev/null
+++ b/sys/src/boot/pc/part.c
@@ -0,0 +1,354 @@
+#include	"u.h"
+#include	"lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+
+#include	"sd.h"
+#include	"fs.h"
+
+enum {
+	Npart = 32
+};
+
+uchar *mbrbuf, *partbuf;
+int nbuf;
+
+#define trace 0
+
+int
+tsdbio(SDunit *unit, SDpart *part, void *a, vlong off, int mbr)
+{
+	uchar *b;
+
+	if(sdbio(unit, part, a, unit->secsize, off) != unit->secsize){
+		if(trace)
+			print("%s: read %lud at %lld failed\n", unit->name,
+				unit->secsize, (vlong)part->start*unit->secsize+off);
+		return -1;
+	}
+	b = a;
+	if(mbr && (b[0x1FE] != 0x55 || b[0x1FF] != 0xAA)){
+		if(trace)
+			print("%s: bad magic %.2ux %.2ux at %lld\n",
+				unit->name, b[0x1FE], b[0x1FF],
+				(vlong)part->start*unit->secsize+off);
+		return -1;
+	}
+	return 0;
+}
+
+/*
+ *  read partition table.  The partition table is just ascii strings.
+ */
+#define MAGIC "plan9 partitions"
+static void
+oldp9part(SDunit *unit)
+{
+	SDpart *pp;
+	char *field[3], *line[Npart+1];
+	ulong n, start, end;
+	int i;
+
+	/*
+	 *  We have some partitions already.
+	 */
+	pp = &unit->part[unit->npart];
+
+	/*
+	 * We prefer partition tables on the second to last sector,
+	 * but some old disks use the last sector instead.
+	 */
+	strcpy(pp->name, "partition");
+	pp->start = unit->sectors - 2;
+	pp->end = unit->sectors - 1;
+
+	if(tsdbio(unit, pp, partbuf, 0, 0) < 0)
+		return;
+
+	if(strncmp((char*)partbuf, MAGIC, sizeof(MAGIC)-1) != 0) {
+		/* not found on 2nd last sector; look on last sector */
+		pp->start++;
+		pp->end++;
+		if(tsdbio(unit, pp, partbuf, 0, 0) < 0)
+			return;
+		if(strncmp((char*)partbuf, MAGIC, sizeof(MAGIC)-1) != 0)
+			return;
+		print("%s: using old plan9 partition table on last sector\n", unit->name);
+	}else
+		print("%s: using old plan9 partition table on 2nd-to-last sector\n", unit->name);
+
+	/* we found a partition table, so add a partition partition */
+	unit->npart++;
+	partbuf[unit->secsize-1] = '\0';
+
+	/*
+	 * parse partition table
+	 */
+	n = getfields((char*)partbuf, line, Npart+1, '\n');
+	if(n && strncmp(line[0], MAGIC, sizeof(MAGIC)-1) == 0){
+		for(i = 1; i < n && unit->npart < SDnpart; i++){
+			if(getfields(line[i], field, 3, ' ') != 3)
+				break;
+			start = strtoull(field[1], 0, 0);
+			end = strtoull(field[2], 0, 0);
+			if(start >= end || end > unit->sectors)
+				break;
+			sdaddpart(unit, field[0], start, end);
+		}
+	}	
+}
+
+static void
+p9part(SDunit *unit, char *name)
+{
+	SDpart *p;
+	char *field[4], *line[Npart+1];
+	uvlong start, end;
+	int i, n;
+
+	p = sdfindpart(unit, name);
+	if(p == nil)
+		return;
+
+	if(tsdbio(unit, p, partbuf, unit->secsize, 0) < 0)
+		return;
+	partbuf[unit->secsize-1] = '\0';
+
+	if(strncmp((char*)partbuf, "part ", 5) != 0)
+		return;
+
+	n = getfields((char*)partbuf, line, Npart+1, '\n');
+	if(n == 0)
+		return;
+	for(i = 0; i < n && unit->npart < SDnpart; i++){
+		if(strncmp(line[i], "part ", 5) != 0)
+			break;
+		if(getfields(line[i], field, 4, ' ') != 4)
+			break;
+		start = strtoull(field[2], 0, 0);
+		end   = strtoull(field[3], 0, 0);
+		if(start >= end || end > unit->sectors)
+			break;
+		sdaddpart(unit, field[1], p->start+start, p->start+end);
+	}
+}
+
+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;
+}
+
+/* 
+ * Fetch the first dos and all plan9 partitions out of the MBR partition table.
+ * We return -1 if we did not find a plan9 partition.
+ */
+static int
+mbrpart(SDunit *unit)
+{
+	Dospart *dp;
+	ulong taboffset, start, end;
+	ulong firstxpart, nxtxpart;
+	int havedos, i, nplan9;
+	char name[10];
+
+	taboffset = 0;
+	dp = (Dospart*)&mbrbuf[0x1BE];
+	{
+		/* get the MBR (allowing for DMDDO) */
+		if(tsdbio(unit, &unit->part[0], mbrbuf,
+		    (vlong)taboffset * unit->secsize, 1) < 0)
+			return -1;
+		for(i=0; i<4; i++)
+			if(dp[i].type == DMDDO) {
+				if(trace)
+					print("DMDDO partition found\n");
+				taboffset = 63;
+				if(tsdbio(unit, &unit->part[0], mbrbuf,
+				    (vlong)taboffset * unit->secsize, 1) < 0)
+					return -1;
+				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(;;) {
+		if(tsdbio(unit, &unit->part[0], mbrbuf,
+		    (vlong)taboffset * unit->secsize, 1) < 0)
+			return -1;
+		if(trace) {
+			if(firstxpart)
+				print("%s ext %lud ", unit->name, taboffset);
+			else
+				print("%s mbr ", unit->name);
+		}
+		nxtxpart = 0;
+		for(i=0; i<4; i++) {
+			if(trace)
+				print("dp %d...", dp[i].type);
+			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);
+				sdaddpart(unit, name, start, end);
+				p9part(unit, name);
+				nplan9++;
+			}
+
+			/*
+			 * We used to take the active partition (and then the first
+			 * when none are active).  We have to take the first here,
+			 * so that the partition we call ``dos'' agrees with the
+			 * partition disk/fdisk calls ``dos''. 
+			 */
+			if(havedos==0 && isdos(dp[i].type)){
+				havedos = 1;
+				sdaddpart(unit, "dos", start, end);
+			}
+
+			/* nxtxpart is relative to firstxpart (or 0), not taboffset */
+			if(isextend(dp[i].type)){
+				nxtxpart = start-taboffset+firstxpart;
+				if(trace)
+					print("link %lud...", nxtxpart);
+			}
+		}
+		if(trace)
+			print("\n");
+
+		if(!nxtxpart)
+			break;
+		if(!firstxpart)
+			firstxpart = nxtxpart;
+		taboffset = nxtxpart;
+	}	
+	return nplan9 ? 0 : -1;
+}
+
+/*
+ * To facilitate booting from CDs, we create a partition for
+ * the boot floppy image embedded in a bootable CD.
+ */
+static int
+part9660(SDunit *unit)
+{
+	uchar buf[2048];
+	ulong a, n;
+	uchar *p;
+
+	if(unit->secsize != 2048)
+		return -1;
+
+	if(sdbio(unit, &unit->part[0], buf, 2048, 17*2048) < 0)
+		return -1;
+
+	if(buf[0] || strcmp((char*)buf+1, "CD001\x01EL TORITO SPECIFICATION") != 0)
+		return -1;
+
+	
+	p = buf+0x47;
+	a = p[0] | (p[1]<<8) | (p[2]<<16) | (p[3]<<24);
+
+	if(sdbio(unit, &unit->part[0], buf, 2048, a*2048) < 0)
+		return -1;
+
+	if(memcmp(buf, "\x01\x00\x00\x00", 4) != 0
+	|| memcmp(buf+30, "\x55\xAA", 2) != 0
+	|| buf[0x20] != 0x88)
+		return -1;
+
+	p = buf+0x28;
+	a = p[0] | (p[1]<<8) | (p[2]<<16) | (p[3]<<24);
+
+	switch(buf[0x21]){
+	case 0x01:
+		n = 1200*1024;
+		break;
+	case 0x02:
+		n = 1440*1024;
+		break;
+	case 0x03:
+		n = 2880*1024;
+		break;
+	default:
+		return -1;
+	}
+	n /= 2048;
+
+	print("found partition %s!cdboot; %lud+%lud\n", unit->name, a, n);
+	sdaddpart(unit, "cdboot", a, a+n);
+	return 0;
+}
+
+enum {
+	NEW = 1<<0,
+	OLD = 1<<1
+};
+
+void
+partition(SDunit *unit)
+{
+	int type;
+	char *p;
+
+	if(unit->part == 0)
+		return;
+
+	if(part9660(unit) == 0)
+		return;
+
+	p = getconf("partition");
+	if(p == nil)
+		p = defaultpartition;
+
+	if(p != nil && strncmp(p, "new", 3) == 0)
+		type = NEW;
+	else if(p != nil && strncmp(p, "old", 3) == 0)
+		type = OLD;
+	else
+		type = NEW|OLD;
+
+	if(nbuf < unit->secsize) {
+		free(mbrbuf);
+		free(partbuf);
+		mbrbuf = malloc(unit->secsize);
+		partbuf = malloc(unit->secsize);
+		if(mbrbuf==nil || partbuf==nil) {
+			free(mbrbuf);
+			free(partbuf);
+			partbuf = mbrbuf = nil;
+			nbuf = 0;
+			return;
+		}
+		nbuf = unit->secsize;
+	}
+
+	/*
+	 * there might be no mbr (e.g. on a very large device), so look for
+	 * a bare plan 9 partition table if mbrpart fails.
+	 */
+	if((type & NEW) && mbrpart(unit) >= 0){
+		/* nothing to do */
+	}
+	else if (type & NEW)
+		p9part(unit, "data");
+	else if(type & OLD)
+		oldp9part(unit);
+}