/**
* nor_erase_prepare - prepare a NOR flash PEB for erasure.
* @ubi: UBI device description object
* @pnum: physical eraseblock number to prepare
*
* NOR flash, or at least some of them, have peculiar embedded PEB erasure
* algorithm: the PEB is first filled with zeroes, then it is erased. And
* filling with zeroes starts from the end of the PEB. This was observed with
* Spansion S29GL512N NOR flash.
*
* This means that in case of a power cut we may end up with intact data at the
* beginning of the PEB, and all zeroes at the end of PEB. In other words, the
* EC and VID headers are OK, but a large chunk of data at the end of PEB is
* zeroed. This makes UBI mistakenly treat this PEB as used and associate it
* with an LEB, which leads to subsequent failures (e.g., UBIFS fails).
*
* This function is called before erasing NOR PEBs and it zeroes out EC and VID
* magic numbers in order to invalidate them and prevent the failures. Returns
* zero in case of success and a negative error code in case of failure.
*/
static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
{
int err;
size_t written;
loff_t addr;
uint32_t data = 0;
struct ubi_ec_hdr ec_hdr;
struct ubi_vid_io_buf vidb;
/*
* Note, we cannot generally define VID header buffers on stack,
* because of the way we deal with these buffers (see the header
* comment in this file). But we know this is a NOR-specific piece of
* code, so we can do this. But yes, this is error-prone and we should
* (pre-)allocate VID header buffer instead.
*/
struct ubi_vid_hdr vid_hdr;
/*
* If VID or EC is valid, we have to corrupt them before erasing.
* It is important to first invalidate the EC header, and then the VID
* header. Otherwise a power cut may lead to valid EC header and
* invalid VID header, in which case UBI will treat this PEB as
* corrupted and will try to preserve it, and print scary warnings.
*/
addr = (loff_t)pnum * ubi->peb_size;
err = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
err != UBI_IO_FF){
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
if(err)
goto error;
}
ubi_init_vid_buf(ubi, &vidb, &vid_hdr);
ubi_assert(&vid_hdr == ubi_get_vid_hdr(&vidb));
err = ubi_io_read_vid_hdr(ubi, pnum, &vidb, 0);
if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
err != UBI_IO_FF){
addr += ubi->vid_hdr_aloffset;
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
if (err)
goto error;
}
return 0;
error:
/*
* The PEB contains a valid VID or EC header, but we cannot invalidate
* it. Supposedly the flash media or the driver is screwed up, so
* return an error.
*/
ubi_err(ubi, "cannot invalidate PEB %d, write returned %d", pnum, err);
ubi_dump_flash(ubi, pnum, 0, ubi->peb_size);
return -EIO;
}
static int ubi_scan_fastmap(struct ubi_scan_info *ubi,
struct ubi_attach_info *ai,
int fm_anchor)
{
struct ubi_fm_sb *fmsb, *fmsb2;
struct ubi_vid_hdr *vh;
struct ubi_fastmap_layout *fm;
int i, used_blocks, pnum, ret = 0;
size_t fm_size;
__be32 crc, tmp_crc;
unsigned long long sqnum = 0;
fmsb = &ubi->fm_sb;
fm = &ubi->fm_layout;
ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
if (ret && ret != UBI_IO_BITFLIPS)
goto free_fm_sb;
else if (ret == UBI_IO_BITFLIPS)
fm->to_be_tortured[0] = 1;
if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
ubi_err("bad super block magic: 0x%x, expected: 0x%x",
be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
ret = UBI_BAD_FASTMAP;
goto free_fm_sb;
}
if (fmsb->version != UBI_FM_FMT_VERSION) {
ubi_err("bad fastmap version: %i, expected: %i",
fmsb->version, UBI_FM_FMT_VERSION);
ret = UBI_BAD_FASTMAP;
goto free_fm_sb;
}
used_blocks = be32_to_cpu(fmsb->used_blocks);
if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
ret = UBI_BAD_FASTMAP;
goto free_fm_sb;
}
fm_size = ubi->leb_size * used_blocks;
if (fm_size != ubi->fm_size) {
ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
ubi->fm_size);
ret = UBI_BAD_FASTMAP;
goto free_fm_sb;
}
vh = &ubi->fm_vh;
for (i = 0; i < used_blocks; i++) {
pnum = be32_to_cpu(fmsb->block_loc[i]);
if (ubi_io_is_bad(ubi, pnum)) {
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
#ifdef LATER
int image_seq;
ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
if (ret && ret != UBI_IO_BITFLIPS) {
ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
i, pnum);
if (ret > 0)
ret = UBI_BAD_FASTMAP;
goto free_hdr;
} else if (ret == UBI_IO_BITFLIPS)
fm->to_be_tortured[i] = 1;
image_seq = be32_to_cpu(ech->image_seq);
if (!ubi->image_seq)
ubi->image_seq = image_seq;
/*
* Older UBI implementations have image_seq set to zero, so
* we shouldn't fail if image_seq == 0.
*/
if (image_seq && (image_seq != ubi->image_seq)) {
ubi_err("wrong image seq:%d instead of %d",
be32_to_cpu(ech->image_seq), ubi->image_seq);
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
#endif
ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
if (ret && ret != UBI_IO_BITFLIPS) {
ubi_err("unable to read fastmap block# %i (PEB: %i)",
i, pnum);
goto free_hdr;
}
/*
* Mainline code rescans the anchor header. We've done
* that already so we merily copy it over.
*/
if (pnum == fm_anchor)
memcpy(vh, ubi->blockinfo + pnum, sizeof(*fm));
if (i == 0) {
if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
ubi_err("bad fastmap anchor vol_id: 0x%x," \
" expected: 0x%x",
be32_to_cpu(vh->vol_id),
UBI_FM_SB_VOLUME_ID);
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
} else {
if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
ubi_err("bad fastmap data vol_id: 0x%x," \
" expected: 0x%x",
be32_to_cpu(vh->vol_id),
UBI_FM_DATA_VOLUME_ID);
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
}
if (sqnum < be64_to_cpu(vh->sqnum))
sqnum = be64_to_cpu(vh->sqnum);
ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
ubi->leb_start, ubi->leb_size);
if (ret && ret != UBI_IO_BITFLIPS) {
ubi_err("unable to read fastmap block# %i (PEB: %i, " \
"err: %i)", i, pnum, ret);
goto free_hdr;
}
}
fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
tmp_crc = be32_to_cpu(fmsb2->data_crc);
fmsb2->data_crc = 0;
crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
if (crc != tmp_crc) {
ubi_err("fastmap data CRC is invalid");
ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
fmsb2->sqnum = sqnum;
fm->used_blocks = used_blocks;
ret = ubi_attach_fastmap(ubi, ai, fm);
if (ret) {
if (ret > 0)
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
ubi->fm = fm;
ubi->fm_pool.max_size = ubi->fm->max_pool_size;
ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
ubi_msg("attached by fastmap %uMB %u blocks",
ubi->fsize_mb, ubi->peb_count);
ubi_dbg("fastmap pool size: %d", ubi->fm_pool.max_size);
ubi_dbg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
out:
if (ret)
ubi_err("Attach by fastmap failed, doing a full scan!");
return ret;
free_hdr:
free_fm_sb:
goto out;
}
/**
* nor_erase_prepare - prepare a NOR flash PEB for erasure.
* @ubi: UBI device description object
* @pnum: physical eraseblock number to prepare
*
* NOR flash, or at least some of them, have peculiar embedded PEB erasure
* algorithm: the PEB is first filled with zeroes, then it is erased. And
* filling with zeroes starts from the end of the PEB. This was observed with
* Spansion S29GL512N NOR flash.
*
* This means that in case of a power cut we may end up with intact data at the
* beginning of the PEB, and all zeroes at the end of PEB. In other words, the
* EC and VID headers are OK, but a large chunk of data at the end of PEB is
* zeroed. This makes UBI mistakenly treat this PEB as used and associate it
* with an LEB, which leads to subsequent failures (e.g., UBIFS fails).
*
* This function is called before erasing NOR PEBs and it zeroes out EC and VID
* magic numbers in order to invalidate them and prevent the failures. Returns
* zero in case of success and a negative error code in case of failure.
*/
static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
{
int err, err1;
size_t written;
loff_t addr;
uint32_t data = 0;
/*
* Note, we cannot generally define VID header buffers on stack,
* because of the way we deal with these buffers (see the header
* comment in this file). But we know this is a NOR-specific piece of
* code, so we can do this. But yes, this is error-prone and we should
* (pre-)allocate VID header buffer instead.
*/
struct ubi_vid_hdr vid_hdr;
/*
* It is important to first invalidate the EC header, and then the VID
* header. Otherwise a power cut may lead to valid EC header and
* invalid VID header, in which case UBI will treat this PEB as
* corrupted and will try to preserve it, and print scary warnings.
*/
addr = (loff_t)pnum * ubi->peb_size;
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
if (!err) {
addr += ubi->vid_hdr_aloffset;
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
if (!err)
return 0;
}
/*
* We failed to write to the media. This was observed with Spansion
* S29GL512N NOR flash. Most probably the previously eraseblock erasure
* was interrupted at a very inappropriate moment, so it became
* unwritable. In this case we probably anyway have garbage in this
* PEB.
*/
err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
err1 == UBI_IO_FF) {
struct ubi_ec_hdr ec_hdr;
err1 = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
err1 == UBI_IO_FF)
/*
* Both VID and EC headers are corrupted, so we can
* safely erase this PEB and not afraid that it will be
* treated as a valid PEB in case of an unclean reboot.
*/
return 0;
}
/*
* The PEB contains a valid VID header, but we cannot invalidate it.
* Supposedly the flash media or the driver is screwed up, so return an
* error.
*/
ubi_err("cannot invalidate PEB %d, write returned %d read returned %d",
pnum, err, err1);
ubi_dump_flash(ubi, pnum, 0, ubi->peb_size);
return -EIO;
}