[Skiboot] [PATCH] Produce XZ compressed skiboot.lid as part of build

Andrew Donnellan andrew.donnellan at au1.ibm.com
Mon Jul 4 13:37:29 AEST 2016

On 04/07/16 13:27, Stewart Smith wrote:
> With a recent HostBoot change, we can have an XZ compressed PAYLOAD
> that's automagically detected (looking at magic numbers).
> This gives us three great benefits:
> 1) it's transparent, uncompressed skiboot.lid works everywhere
> 2) it lets us grow greater than 1MB binary, as long as we compress
>    down to <1MB
> 3) It speeds up boot. We currently compress down to 230kb rather than
>    922kb, which is much quicker to read off flash.
> This patch produces skiboot.lid.xz alongside standard skiboot.lid.
> Signed-off-by: Stewart Smith <stewart at linux.vnet.ibm.com>
> ---
> +$(TARGET).lid.xz: $(TARGET).lid
> +	$(call Q,XZ, cat $^ | xz -9 -C crc32 > $@, $@)

Is crc32 the only check algorithm supported by Hostboot? *searches 
hostboot source code...*

A quick look at the relevant Hostboot source code seems to indicate that 
crc64 can be enabled but is disabled by default. Mention this in commit 

Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan at au1.ibm.com  IBM Australia Limited

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