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EBR could contain an early stage of boot code. But we do not support it.

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Remove message about non empty bootcode, we can not break something
while GEOM_PART_EBR_COMPAT is defined.

But without GEOM_PART_EBR_COMPAT any changes in EBR are allowed and we
can accidentally wipe the boot code. To do not break anything save
the first EBR chunk and keep it untouched each time when we are
changing EBR. Note that we are still not support boot code for EBR.

PR:		kern/141235
MFC after:	1 month
This commit is contained in:
Andrey V. Elsukov 2011-06-27 12:42:48 +00:00
parent 812f1d32e7
commit 671dfdbf11
1 changed files with 20 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
sys/geom/part/g_part_ebr.c
View File

@ -59,6 +59,9 @@ FEATURE(geom_part_ebr_compat,
struct g_part_ebr_table {
struct g_part_table base;
#ifndef GEOM_PART_EBR_COMPAT
u_char ebr[EBRSIZE];
#endif
};
struct g_part_ebr_entry {
@ -459,7 +462,7 @@ g_part_ebr_read(struct g_part_table *basetable, struct g_consumer *cp)
u_char *buf;
off_t ofs, msize;
u_int lba;
int error, index, sum;
int error, index;
pp = cp->provider;
table = (struct g_part_ebr_table *)basetable;
@ -482,20 +485,11 @@ g_part_ebr_read(struct g_part_table *basetable, struct g_consumer *cp)
printf("GEOM: %s: invalid entries in the EBR ignored.\n",
pp->name);
}
/* We do not support bootcode for EBR. If bootcode area is
* not zeroes, then mark this EBR as corrupt to do not break
* anything for another OS'es.
*/
if (lba == 0) {
sum = 0;
for (index = 0; index < DOSPARTOFF; index++)
sum += buf[index];
if (sum != 0) {
basetable->gpt_corrupt = 1;
printf("GEOM: %s: EBR has non empty bootcode.\n",
pp->name);
}
}
#ifndef GEOM_PART_EBR_COMPAT
/* Save the first EBR, it can contain a boot code */
if (lba == 0)
bcopy(buf, table->ebr, sizeof(table->ebr));
#endif
g_free(buf);
if (ent[0].dp_typ == 0)
@ -583,6 +577,9 @@ g_part_ebr_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
static int
g_part_ebr_write(struct g_part_table *basetable, struct g_consumer *cp)
{
#ifndef GEOM_PART_EBR_COMPAT
struct g_part_ebr_table *table;
#endif
struct g_provider *pp;
struct g_part_entry *baseentry, *next;
struct g_part_ebr_entry *entry;
@ -592,6 +589,10 @@ g_part_ebr_write(struct g_part_table *basetable, struct g_consumer *cp)
pp = cp->provider;
buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
#ifndef GEOM_PART_EBR_COMPAT
table = (struct g_part_ebr_table *)basetable;
bcopy(table->ebr, buf, DOSPARTOFF);
#endif
le16enc(buf + DOSMAGICOFFSET, DOSMAGIC);
baseentry = LIST_FIRST(&basetable->gpt_entry);
@ -644,7 +645,10 @@ g_part_ebr_write(struct g_part_table *basetable, struct g_consumer *cp)
error = g_write_data(cp, baseentry->gpe_start * pp->sectorsize,
buf, pp->sectorsize);
#ifndef GEOM_PART_EBR_COMPAT
if (baseentry->gpe_start == 0)
bzero(buf, DOSPARTOFF);
#endif
baseentry = next;
} while (!error && baseentry != NULL);