5 sec boot
NoiseEHC at freemail.hu
Sun Oct 5 14:24:14 EDT 2008
When I will finally have some time (currently I am working even on
weekends) I will finish my half made zlib decompression code.
Where is that Security hash's code?
Mitch Bradley wrote:
> Memory to memory copy: 500 MB/s
> Raw NAND FLASH read: 20 MB/s
> Security hash: 4 MB/s
> So overlapping hash calculation with NAND FLASH read is of limited
> value, and trying to overlap anything with memory copy is almost
> certainly counterproductive.
> This discussion seem to be degenerating into a brainstorming session
> about an sub-problem that is pretty well under control (the firmware
> component of the boot time). I've been working diligently on that
> sub-problem for nearly 2 years now, and I think I have an excellent
> grasp of where the cycles are going and what can be done to improve
> it. The only significant opportunity at this point is to reduce the
> JFFS2 time, which will require either partitioning or abandoning JFFS2
> for the boot files, or both. UBI+UBIFS is one workable approach in
> the context of a Linux-only machine. There are some others, such as
> Redboot partitions with a small boot partition and a large system
> partition, with various FS possibilities for the two partitions. The
> quickest path to a deliverable system would be Redboot + JFFS2 boot
> partition + UBI system partition.
> The rest of the "fruit" on the tree is solidly in the OS domain,
> encompassing kernel startup, userland startup/initscripts, X startup,
> and Sugar / application startup. I would encourage each of you to
> address the areas in which you have special expertise, and then to
> take action.
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