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author | Tom Rini <trini@konsulko.com> | 2019-10-17 07:26:16 -0400 |
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committer | Tom Rini <trini@konsulko.com> | 2019-10-17 07:26:16 -0400 |
commit | a2fce50455c9831f36765e5813b0b5e98f55d70b (patch) | |
tree | 4a0d4bfaf6392a1639b93ce4f09e9f0f68aa63b9 /doc | |
parent | c83b1bb923421e95e499b22b010d2f9f463c1226 (diff) | |
parent | 611623417403256dc79205a89d4dc7f826bc805f (diff) | |
download | u-boot-a2fce50455c9831f36765e5813b0b5e98f55d70b.zip u-boot-a2fce50455c9831f36765e5813b0b5e98f55d70b.tar.gz u-boot-a2fce50455c9831f36765e5813b0b5e98f55d70b.tar.bz2 |
Merge tag 'for-v2020.01' of https://gitlab.denx.de/u-boot/custodians/u-boot-ubi
ubi enhancements for 2020.01
- provide a way for skipping crc checks ported from linux, and add an
U-Boot command to set this flag on already installed systems.
- fix redundand environment management
Diffstat (limited to 'doc')
-rw-r--r-- | doc/README.ubi | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/doc/README.ubi b/doc/README.ubi index 9efab6c..c78a817 100644 --- a/doc/README.ubi +++ b/doc/README.ubi @@ -223,3 +223,36 @@ For example: => ubifsumount Unmounting UBIFS volume recovery! + + +Usage of the UBI CRC skip-check flag of static volumes: +------------------------------------------------------- +Some users of static UBI volumes implement their own integrity check, +thus making the volume CRC check done at open time useless. For +instance, this is the case when one use the ubiblock + dm-verity + +squashfs combination, where dm-verity already checks integrity of the +block device but this time at the block granularity instead of verifying +the whole volume. + +Skipping this test drastically improves the boot-time. + +U-Boot now supports the "skip_check" flag to optionally skip the CRC +check at open time. + +Usage: Case A - Upon UBI volume creation: +You can optionally add "--skipcheck" to the "ubi create" command: + +ubi create[vol] volume [size] [type] [id] [--skipcheck] + - create volume name with size ('-' for maximum available size) + +Usage: Case B - With an already existing UBI volume: +Use the "ubi skipcheck" command: + +ubi skipcheck volume on/off - Set or clear skip_check flag in volume header + +Example: +=> ubi skipcheck rootfs0 on +Setting skip_check on volume rootfs0 + +BTW: This saves approx. 10 seconds Linux bootup time on a MT7688 based +target with 128MiB of SPI NAND. |