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-rw-r--r--README85
1 files changed, 85 insertions, 0 deletions
diff --git a/README b/README
index 1d71359..1e63f04 100644
--- a/README
+++ b/README
@@ -1152,6 +1152,7 @@ The following options need to be configured:
CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
+ CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
CONFIG_RTC_DS164x - use Dallas DS164x RTC
CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
@@ -2036,6 +2037,24 @@ CBFS (Coreboot Filesystem) support
4th and following
BOOTP requests: delay 0 ... 8 sec
+ CONFIG_BOOTP_ID_CACHE_SIZE
+
+ BOOTP packets are uniquely identified using a 32-bit ID. The
+ server will copy the ID from client requests to responses and
+ U-Boot will use this to determine if it is the destination of
+ an incoming response. Some servers will check that addresses
+ aren't in use before handing them out (usually using an ARP
+ ping) and therefore take up to a few hundred milliseconds to
+ respond. Network congestion may also influence the time it
+ takes for a response to make it back to the client. If that
+ time is too long, U-Boot will retransmit requests. In order
+ to allow earlier responses to still be accepted after these
+ retransmissions, U-Boot's BOOTP client keeps a small cache of
+ IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
+ cache. The default is to keep IDs for up to four outstanding
+ requests. Increasing this will allow U-Boot to accept offers
+ from a BOOTP client in networks with unusually high latency.
+
- DHCP Advanced Options:
You can fine tune the DHCP functionality by defining
CONFIG_BOOTP_* symbols:
@@ -3319,6 +3338,9 @@ FIT uImage format:
Adds the MTD partitioning infrastructure from the Linux
kernel. Needed for UBI support.
+ CONFIG_MTD_NAND_VERIFY_WRITE
+ verify if the written data is correct reread.
+
- UBI support
CONFIG_CMD_UBI
@@ -3332,6 +3354,64 @@ FIT uImage format:
Make the verbose messages from UBI stop printing. This leaves
warnings and errors enabled.
+
+ CONFIG_MTD_UBI_WL_THRESHOLD
+ This parameter defines the maximum difference between the highest
+ erase counter value and the lowest erase counter value of eraseblocks
+ of UBI devices. When this threshold is exceeded, UBI starts performing
+ wear leveling by means of moving data from eraseblock with low erase
+ counter to eraseblocks with high erase counter.
+
+ The default value should be OK for SLC NAND flashes, NOR flashes and
+ other flashes which have eraseblock life-cycle 100000 or more.
+ However, in case of MLC NAND flashes which typically have eraseblock
+ life-cycle less than 10000, the threshold should be lessened (e.g.,
+ to 128 or 256, although it does not have to be power of 2).
+
+ default: 4096
+
+ CONFIG_MTD_UBI_BEB_LIMIT
+ This option specifies the maximum bad physical eraseblocks UBI
+ expects on the MTD device (per 1024 eraseblocks). If the
+ underlying flash does not admit of bad eraseblocks (e.g. NOR
+ flash), this value is ignored.
+
+ NAND datasheets often specify the minimum and maximum NVM
+ (Number of Valid Blocks) for the flashes' endurance lifetime.
+ The maximum expected bad eraseblocks per 1024 eraseblocks
+ then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
+ which gives 20 for most NANDs (MaxNVB is basically the total
+ count of eraseblocks on the chip).
+
+ To put it differently, if this value is 20, UBI will try to
+ reserve about 1.9% of physical eraseblocks for bad blocks
+ handling. And that will be 1.9% of eraseblocks on the entire
+ NAND chip, not just the MTD partition UBI attaches. This means
+ that if you have, say, a NAND flash chip admits maximum 40 bad
+ eraseblocks, and it is split on two MTD partitions of the same
+ size, UBI will reserve 40 eraseblocks when attaching a
+ partition.
+
+ default: 20
+
+ CONFIG_MTD_UBI_FASTMAP
+ Fastmap is a mechanism which allows attaching an UBI device
+ in nearly constant time. Instead of scanning the whole MTD device it
+ only has to locate a checkpoint (called fastmap) on the device.
+ The on-flash fastmap contains all information needed to attach
+ the device. Using fastmap makes only sense on large devices where
+ attaching by scanning takes long. UBI will not automatically install
+ a fastmap on old images, but you can set the UBI parameter
+ CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
+ that fastmap-enabled images are still usable with UBI implementations
+ without fastmap support. On typical flash devices the whole fastmap
+ fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
+
+ CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
+ Set this parameter to enable fastmap automatically on images
+ without a fastmap.
+ default: 0
+
- UBIFS support
CONFIG_CMD_UBIFS
@@ -4370,6 +4450,11 @@ use the "saveenv" command to store a valid environment.
later, once stdio is running and output goes to the LCD, if
present.
+- CONFIG_BOARD_SIZE_LIMIT:
+ Maximum size of the U-Boot image. When defined, the
+ build system checks that the actual size does not
+ exceed it.
+
Low Level (hardware related) configuration options:
---------------------------------------------------