diff options
| -rw-r--r-- | sys/src/cmd/disk/prep/edisk.c | 47 |
1 files changed, 41 insertions, 6 deletions
diff --git a/sys/src/cmd/disk/prep/edisk.c b/sys/src/cmd/disk/prep/edisk.c index d8edc846a..cd2800815 100644 --- a/sys/src/cmd/disk/prep/edisk.c +++ b/sys/src/cmd/disk/prep/edisk.c @@ -610,6 +610,33 @@ readtab(Edit *edit, Header *hdr) return 0; } +static char* +checkhdr(Header *a, Header *b) +{ + if(memcmp(a->sig, b->sig, sizeof(a->sig)) != 0) + return "signature"; + if(memcmp(a->rev, b->rev, sizeof(a->rev)) != 0) + return "revision"; + if(memcmp(a->hdrsiz, b->hdrsiz, sizeof(a->hdrsiz)) != 0) + return "header size"; + if(memcmp(a->selflba, b->backlba, sizeof(a->selflba)) != 0 + || memcmp(a->backlba, b->selflba, sizeof(a->backlba)) != 0) + return "backup lba/self lba"; + if(memcmp(a->firstlba, b->firstlba, sizeof(a->firstlba)) != 0) + return "first lba"; + if(memcmp(a->lastlba, b->lastlba, sizeof(a->lastlba)) != 0) + return "last lba"; + if(memcmp(a->devid, b->devid, sizeof(a->devid)) != 0) + return "device guid"; + if(memcmp(a->entrycount, b->entrycount, sizeof(a->entrycount)) != 0) + return "entry count"; + if(memcmp(a->entrysize, b->entrysize, sizeof(a->entrysize)) != 0) + return "entry size"; + if(memcmp(a->tabcrc, b->tabcrc, sizeof(a->tabcrc)) != 0) + return "table checksum"; + return nil; +} + static Header* getbakhdr(Edit *edit, Header *bhdr) { @@ -619,9 +646,17 @@ getbakhdr(Edit *edit, Header *bhdr) siz = getle32(bhdr->hdrsiz); lba = getle64(bhdr->backlba); - hdr = readhdr(edit->disk, lba); - if(hdr != nil) - return hdr; + + if(!blank){ + char *mismatch; + + mismatch = "data"; + hdr = readhdr(edit->disk, lba); + if(hdr != nil && (mismatch = checkhdr(bhdr, hdr)) == nil) + return hdr; + fprint(2, "backup header at lba %lld has mismatching %s, restoring.\n", + lba, mismatch); + } hdr = getblock(edit->disk, lba); memmove(hdr, bhdr, siz); @@ -756,13 +791,13 @@ initmbr(Disk *disk) t->type = 0xEE; t->active = 0; - size = disk->secs > 0xFFFFFFFF ? 0xFFFFFFFF : disk->secs; - putle32(t->lba, 0); + size = (disk->secs - 1) > 0xFFFFFFFF ? 0xFFFFFFFF : (disk->secs - 1); + putle32(t->lba, 1); putle32(t->size, size); t->starth = 0; t->startc = 0; - t->starts = 0; + t->starts = 1; t->endh = disk->h-1; t->ends = (disk->s & 0x3F) | (((disk->c-1)>>2) & 0xC0); t->endc = disk->c-1; |