[U-Boot] Brotli Compression to Fit Image/bzImage

[Simon Glass]

Hi,

On 1 July 2016 at 00:13, vinoth eswaran <evinoth1206 at gmail.com> wrote:
> Hello,
>
>  I am working on an embedded project using Minnowboard Max with U-boot
> and customised Linux kernel.
>
> To optimize boot time, currently I am comparing the different
> comparison algorithms and have read about Brotli compression, which
> seems to be good. So I have planned to test and see how good is Brotli
> compression for my use case? The current Linux kernel and U-boot
> doesn't support this compression, so I have to add this compression
> algorithm code.
>
> I am seeing two ways of doing this,
>
> 1. In U-Boot
>
> Fit Image creation from vmlinux. Adding Brotli compression to mkimage
> tool and decompressor to U-Boot.
> Here we are using mkimage tool to create the image.fit. I can do some
> changes in mkimage and add the decompressor to the U-boot code
>
> 2. In Linux Kernel
>
> bzImage --> adding the Brotli compression and decompression to Linux Kernel
>
> and change the default compression from gzip to brotli in the Linux
> kernel Configuration.
>
> I don't know which way is comparably easier to implement, any
> suggestions on these topic will be of great help. Have any body tried
> this algorithm for the Linux Kernel??

I suggest going with option 1. U-Boot supports several algorithms so
another one is pretty easy to add. The last one was IH_COMP_LZ4, so
you can search for that in the code. The commit was:

027b728d Add support for LZ4 decompression algorithm

Regards,
Simon