OLPC Firmware q3a65: Difference between revisions
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*add support for sparse .zd files, decreasing ''fs-update'' time, |
*add support for sparse .zd files, decreasing ''fs-update'' time, |
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*disable ''fs-update'' erase step, |
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*revised ''help'' display, |
*revised ''help'' display, |
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(There is now an installation time advantage to smaller operating system builds). |
(There is now an installation time advantage to smaller operating system builds). |
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=== fs-update erase === |
=== fs-update disable erase === |
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The fix for failure to erase whole disk exposed a problem with some cards. We now split the erase into 16 segments, and check for completion of the erase prevented erase interruption, resulting in these cards being properly erased. |
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In Q3A64 and earlier, ''fs-update'' used to erase one 256th of the microSD card before starting to write to the card. This was removed, because it was unnecessary, because some cards did not behave well, and if extended to the whole card it broke NANDblaster. |
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The user experience changes to ''fs-update'' are: |
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*there is a delay while erasure occurs (previously erasure was covering 1/256th of the card so the delay was not obvious), |
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A revised ''help'' output: |
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*during the delay a ~ (tilde) is displayed on the status line, and the storage LED blinks 8 times, |
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The length of the delay depends on the type of card, and how much work the card has to do. Workload depends on the size of the image to be installed, and the size of the image already on the card. In our tests it is no more than about 15 seconds (Toshiba SD, SanDisk microSD 4GB 2009), and no less than about 33ms (SanDisk 4GB 2010). |
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UPDATES: |
UPDATES: |
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Revision as of 00:09, 30 April 2011
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NOTE: The contents of this page are not set in stone, and are subject to change! This page is a draft in active flux ... |
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- add support for sparse .zd files, decreasing fs-update time,
- disable fs-update erase step,
- revised help display,
fs-update sparse .zd files
Sparse .zd files do not include unused filesystem blocks. As a result, installation time for 10.1.3 falls from 14 minutes to 7 minutes ... if the .zd file is processed. Patches to olpc-os-builder are available for future builds.
(There is now an installation time advantage to smaller operating system builds).
fs-update disable erase
In Q3A64 and earlier, fs-update used to erase one 256th of the microSD card before starting to write to the card. This was removed, because it was unnecessary, because some cards did not behave well, and if extended to the whole card it broke NANDblaster.
help
A revised help output:
UPDATES: fs-update u:\os1.zd4 Rewrite the OS on internal SD from USB drive flash u:\q3a64.rom Rewrite the firmware from USB drive flash ext:\q3a64.rom Rewrite the firmware from external SD file DIRECTORY LISTING: dir u:\ List USB drive root directory dir u:\boot\ List USB drive /boot directory dir int:\boot\*.zip List .zip files in internal SD /boot directory BOOTING: boot Start the OS from list of default locations printenv boot-device Show the list of default locations used by boot boot u:\test.fth Start the OS from a specific location CONFIGURATION VARIABLES FOR BOOTING: boot-device Kernel or boot script paths. Example: ext:\boot\olpc.fth boot-file Default kernel command line. Example: console=ttyS0,115200 ramdisk Initial RAMDISK path. Example: int:\boot\initrd.img MANAGING CONFIGURATION VARIABLES: printenv [ <name> ] Show configuration variables setenv <name> <value> Set configuration variable editenv <name> Edit configuration variable DIAGNOSTICS: test <device-name> Test device. Example: test mouse test-all Test all devices that have test routines menu Graphical interface to selftests More information: http://wiki.laptop.org/go/OFW_FAQ