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- #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];
- if(1) {
- /* 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;
- }
- if((type & NEW) && mbrpart(unit) >= 0){
- /* nothing to do */;
- }
- else if(type & OLD)
- oldp9part(unit);
- }
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