[SLOF] [PATCH slof] fdt: Pass the resulting device tree to QEMU

Alexey Kardashevskiy aik at ozlabs.ru
Sat Sep 30 09:48:11 AEST 2017

On 29/09/17 19:07, Alexey Kardashevskiy wrote:
> This creates flatten device tree and passes it to QEMU via a custom
> hypercall right before jumping to RTAS.
> On a machine with 256 CPUs and 256 virtual Intel E1000 devices the blob
> is 360KB (356KB structs and 4KB of strings), building such a tree takes
> 2.8s on a POWER8 box. A simple tree with 1 CPU and a couple of devices
> takes 43ms and creates 16KB blob.
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
> ---
> I tested the blob by storing it from QEMU to a file (RFC patch is
> coming next) and decompiling it; this produces error which I do not really
> understand as the name of the root is an empty string (literaly:
> 00 00 00 01  00 00 00 00) and yet this error:
> aik at fstn1-p1:~$ dtc -f -I dtb -O dts -o dbg.dts dbg.dtb
> ERROR (name_properties): "name" property in / is incorrect ("/" instead of base node name)
> Warning: Input tree has errors, output forced

Forgot to mention - the resulting tree does not phandles (which is the
whole purpose of the patch), I'll have to add them manually :)


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