5 sec boot

NoiseEHC 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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