/*
* read disk partition tables, intended for early use on systems
* that don't use 9load. borrowed from 9load.
*/
#include <u.h>
#include <libc.h>
#include <auth.h>
#include <fcall.h>
#include <bio.h>
#include "../boot/boot.h"
typedef struct Fs Fs;
#include "/sys/src/boot/pc/dosfs.h"
#define GSHORT(p) (((p)[1]<<8)|(p)[0])
#define GLONG(p) ((GSHORT((p)+2)<<16)|GSHORT(p))
#define trace 0
enum {
parttrace = 0,
Npart = 64,
SDnpart = Npart,
Maxsec = 2048,
Cdsec = 2048,
Normsec = 512, /* disks */
NAMELEN = 256, /* hack */
};
typedef struct SDpart SDpart;
typedef struct SDunit SDunit;
typedef struct SDpart {
uvlong start;
uvlong end;
char name[NAMELEN];
int valid;
} SDpart;
typedef struct SDunit {
int ctl; /* fds */
int data;
char name[NAMELEN];
uvlong sectors;
ulong secsize;
SDpart* part;
int npart; /* of valid partitions */
} SDunit;
static uchar *mbrbuf, *partbuf;
static void
sdaddpart(SDunit* unit, char* name, uvlong start, uvlong end)
{
SDpart *pp;
int i, partno;
if(parttrace)
print("add %d %s %s %lld %lld\n", unit->npart, unit->name, name, start, end);
/*
* Check name not already used
* and look for a free slot.
*/
if(unit->part != nil){
partno = -1;
for(i = 0; i < SDnpart; i++){
pp = &unit->part[i];
if(!pp->valid){
if(partno == -1)
partno = i;
break;
}
if(strcmp(name, pp->name) == 0){
if(pp->start == start && pp->end == end){
if(parttrace)
print("already present\n");
return;
}
}
}
}else{
if((unit->part = malloc(sizeof(SDpart)*SDnpart)) == nil){
if(parttrace)
print("malloc failed\n");
return;
}
partno = 0;
}
/*
* Check there is a free slot and size and extent are valid.
*/
if(partno == -1 || start > end || end > unit->sectors){
print("cannot add %s!%s [%llud,%llud) to disk [0,%llud): %s\n",
unit->name, name, start, end, unit->sectors,
partno==-1 ? "no free partitions" : "partition boundaries out of range");
return;
}
pp = &unit->part[partno];
pp->start = start;
pp->end = end;
strncpy(pp->name, name, NAMELEN);
pp->valid = 1;
unit->npart++;
/* update devsd's in-memory partition table */
if (fprint(unit->ctl, "part %s %lld %lld\n", name, start, end) < 0)
fprint(2, "can't update %s's devsd partition table for %s: %r\n",
unit->name, name);
dprint("part %s %lld %lld\n", name, start, end);
}
static long
sdread(SDunit *unit, SDpart *pp, void* va, long len, vlong off)
{
long l, secsize;
uvlong bno, nb;
/*
* Check the request is within partition bounds.
*/
secsize = unit->secsize;
if (secsize == 0)
sysfatal("sdread: zero sector size");
bno = off/secsize + pp->start;
nb = (off+len+secsize-1)/secsize + pp->start - bno;
if(bno+nb > pp->end)
nb = pp->end - bno;
if(bno >= pp->end || nb == 0)
return 0;
seek(unit->data, bno * secsize, 0);
assert(va); /* "sdread" */
l = read(unit->data, va, len);
if (l < 0)
return 0;
return l;
}
static int
sdreadblk(SDunit *unit, SDpart *part, void *a, vlong off, int mbr)
{
uchar *b;
assert(a); /* sdreadblk */
if(sdread(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;
uvlong 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;
dprint("oldp9part %s\n", unit->name);
if(sdreadblk(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(sdreadblk(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 = gettokens((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(gettokens(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 SDpart*
sdfindpart(SDunit *unit, char *name)
{
int i;
if(parttrace)
print("findpart %d %s %s: ", unit->npart, unit->name, name);
for(i=0; i<unit->npart; i++) {
if(parttrace)
print("%s...", unit->part[i].name);
if(strcmp(unit->part[i].name, name) == 0){
if(parttrace)
print("\n");
return &unit->part[i];
}
}
if(parttrace)
print("not found\n");
return nil;
}
/*
* look for a plan 9 partition table on drive `unit' in the second
* sector (sector 1) of partition `name'.
* if found, add the partitions defined in the table.
*/
static void
p9part(SDunit *unit, char *name)
{
SDpart *p;
char *field[4], *line[Npart+1];
uvlong start, end;
int i, n;
dprint("p9part %s %s\n", unit->name, name);
p = sdfindpart(unit, name);
if(p == nil)
return;
if(sdreadblk(unit, p, partbuf, unit->secsize, 0) < 0)
return;
partbuf[unit->secsize-1] = '\0';
if(strncmp((char*)partbuf, "part ", 5) != 0)
return;
n = gettokens((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(gettokens(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);
}
}
static int
isdos(int t)
{
return t==FAT12 || t==FAT16 || t==FATHUGE || t==FAT32 || t==FAT32X;
}
static 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;
uvlong taboffset, start, end;
uvlong firstxpart, nxtxpart;
int havedos, i, nplan9;
char name[10];
taboffset = 0;
dp = (Dospart*)&mbrbuf[0x1BE];
{
/* get the MBR (allowing for DMDDO) */
if(sdreadblk(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(sdreadblk(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(sdreadblk(unit, &unit->part[0], mbrbuf,
(vlong)taboffset * unit->secsize, 1) < 0)
return -1;
if(trace) {
if(firstxpart)
print("%s ext %llud ", 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 %llud...", 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[Maxsec];
ulong a, n;
uchar *p;
if(unit->secsize != Cdsec)
return -1;
if(sdread(unit, &unit->part[0], buf, Cdsec, 17*Cdsec) < 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(sdread(unit, &unit->part[0], buf, Cdsec, a*Cdsec) < 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 /= Cdsec;
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
};
/*
* read unit->data to look for partition tables.
* if found, stash partitions in environment and write them to ctl too.
*/
static void
partition(SDunit *unit)
{
int type;
char *p;
if(unit->part == 0)
return;
if(part9660(unit) == 0)
return;
p = getenv("partition");
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(mbrbuf == nil) {
mbrbuf = malloc(Maxsec);
partbuf = malloc(Maxsec);
if(mbrbuf==nil || partbuf==nil) {
free(mbrbuf);
free(partbuf);
partbuf = mbrbuf = nil;
return;
}
}
/*
* 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);
}
static void
rdgeom(SDunit *unit)
{
char *line;
char *flds[5];
Biobuf bb;
Biobuf *bp;
static char geom[] = "geometry ";
bp = &bb;
seek(unit->ctl, 0, 0);
Binit(bp, unit->ctl, OREAD);
while((line = Brdline(bp, '\n')) != nil){
line[Blinelen(bp) - 1] = '\0';
if (strncmp(line, geom, sizeof geom - 1) == 0)
break;
}
if (line != nil && tokenize(line, flds, nelem(flds)) >= 3) {
unit->sectors = atoll(flds[1]);
unit->secsize = atoll(flds[2]);
}
Bterm(bp);
seek(unit->ctl, 0, 0);
}
static void
setpartitions(char *name, int ctl, int data)
{
SDunit sdunit;
SDunit *unit;
SDpart *part0;
unit = &sdunit;
memset(unit, 0, sizeof *unit);
unit->ctl = ctl;
unit->data = data;
unit->secsize = Normsec; /* default: won't work for CDs */
unit->sectors = ~0ull;
rdgeom(unit);
strncpy(unit->name, name, sizeof unit->name);
unit->part = mallocz(sizeof(SDpart) * SDnpart, 1);
part0 = &unit->part[0];
part0->end = unit->sectors - 1;
strcpy(part0->name, "data");
part0->valid = 1;
unit->npart++;
mbrbuf = malloc(Maxsec);
partbuf = malloc(Maxsec);
partition(unit);
free(unit->part);
}
/*
* read disk partition tables so that readnvram via factotum
* can see them.
*/
int
readparts(void)
{
int i, n, ctl, data, fd;
char *name, *ctlname, *dataname;
Dir *dir;
fd = open("/dev", OREAD);
if(fd < 0)
return -1;
n = dirreadall(fd, &dir);
close(fd);
for(i = 0; i < n; i++) {
name = dir[i].name;
if (strncmp(name, "sd", 2) != 0)
continue;
ctlname = smprint("/dev/%s/ctl", name);
dataname = smprint("/dev/%s/data", name);
if (ctlname == nil || dataname == nil) {
free(ctlname);
free(dataname);
continue;
}
ctl = open(ctlname, ORDWR);
data = open(dataname, OREAD);
free(ctlname);
free(dataname);
if (ctl >= 0 && data >= 0)
setpartitions(dataname, ctl, data);
close(ctl);
close(data);
}
free(dir);
return 0;
}
|
