[Skiboot] [PATCH v10 00/31] little endian skiboot

Cédric Le Goater clg at kaod.org
Wed Jan 22 03:41:47 AEDT 2020

On 1/21/20 12:33 PM, Nicholas Piggin wrote:
> Oliver O'Halloran's on January 20, 2020 4:21 pm:
>> On Sun, Dec 8, 2019 at 11:24 PM Nicholas Piggin <npiggin at gmail.com> wrote:
>>> A few reasons for this:
>>> - The rest of the software is moving (moved) to LE. BE is still
>>>   supported, but the fact is LE will be better tested from now on in
>>>   terms of toolchain.
>>> - ELFv2 ABI is a smaller image, nicer asm code. We can use ELFv2 with BE
>>>   but toolchain won't officially support or test it.
>>> - Some levels of OpenPOWER ISA allow a conforming implementation to
>>>   implement LE only.
>>> - Less stack usage of ELFv2 facilitates OPAL call convention that uses
>>>   the host kernel stack (which is a whole different story but has
>>>   benefits).
>>> - Common endian with the host kernel can help with debugging skiboot
>>>   with host kernel facilities (like BUG, xmon). We could achieve the
>>>   same by teaching kernel about different endianness, but it's more work.
>> Thanks, merged to master as 266573939475c2ad4c93182a0775b8aaff348642
>> Going forwards we probably want some more CI to check for BE vs LE
>> regressions. I'm not too sure what to do there other than more boot
>> testing though.
> Booting to Linux should be a pretty good start for CI if you have
> some PHB and XIVE. Beyond that there's a lot of obscure and/or crufty
> features that'll be hard to get tested without flipping the default
> I guess.

I gave it a try on a boston. host and guest boot fine.

QEMU boots correctly also. Here is the command line :

qemu-system-ppc64 -m 4G -machine powernv9 -smp 2,cores=2,threads=1 -accel tcg,thread=single \
-kernel ./witherspoon-latest/zImage.epapr -initrd ./witherspoon-latest/rootfs.cpio.xz 
-bios ./skiboot.lid \
-device ich9-ahci,id=sata0,bus=pcie.1,addr=0x0 \
-drive file=./ubuntu-ppc64le-powernv.raw,if=none,id=drive0,format=raw,cache=none \
-device ide-hd,bus=sata0.0,unit=0,drive=drive0,id=ide,bootindex=1 \
-device e1000e,netdev=net0,mac=C0:FF:EE:00:00:02,bus=pcie.2,addr=0x0 \
-netdev bridge,helper=/usr/libexec/qemu-bridge-helper,br=virbr0,id=net0 \
-device nec-usb-xhci,bus=pcie.1,addr=0x7 -serial mon:stdio -nographic -nodefaults


More information about the Skiboot mailing list