On 5/12/22 06:42, Daniel Henrique Barboza wrote:
On 5/6/22 02:51, Alexey Kardashevskiy wrote:
The alternative small firmware needs a few words of what it can and
absolutely cannot do; this adds those words.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
docs/system/ppc/pseries.rst | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/docs/system/ppc/pseries.rst b/docs/system/ppc/pseries.rst
index d9b65ad4e850..4c98a94f9add 100644
--- a/docs/system/ppc/pseries.rst
+++ b/docs/system/ppc/pseries.rst
@@ -32,14 +32,42 @@ Missing devices
Firmware
========
+The pSeries platform in QEMU comes with 2 firmwares:
+
`SLOF <https://github.com/aik/SLOF>`_ (Slimline Open Firmware) is an
implementation of the `IEEE 1275-1994, Standard for Boot
(Initialization
Configuration) Firmware: Core Requirements and Practices
<https://standards.ieee.org/standard/1275-1994.html>`_.
+SLOF performs bus scanning, PCI resource allocation, provides the client
+interface to boot from block devices and network.
+
QEMU includes a prebuilt image of SLOF which is updated when a more
recent
version is required.
+VOF (Virtual Open Firmware) is a minimalistic firmware to work with
+``-machine pseries,x-vof=on``. When enabled, the firmware acts as a slim
+shim and QEMU implements parts of the IEEE 1275 Open Firmware interface.
+
+VOF does not have device drivers, does not do PCI resource allocation
and
+relies on ``-kernel`` used with Linux kernels recent enough (v5.4+)
+to PCI resource assignment. It is ideal to use with petitboot.
+
+Booting via ``-kernel`` supports the following:
++-------------------+-------------------+------------------+
+| kernel | pseries,x-vof=off | pseries,x-vof=on |
++===================+===================+==================+
+| vmlinux BE | ✓ | ✓ |
++-------------------+-------------------+------------------+
+| vmlinux LE | ✓ | ✓ |
++-------------------+-------------------+------------------+
+| zImage.pseries BE | x | ✓¹ |
++-------------------+-------------------+------------------+
+| zImage.pseries LE | ✓ | ✓ |
++-------------------+-------------------+------------------+
You need an empty line at the start and at the end of the table.
Otherwise it'll
be rendered as regular text.
How do you build htmls from these btw?
+Notes:
I also don't believe you need the "Notes:" addendum here. It's clear
that you're
making an observation about the zImage.pseries BE and x-vof=on case.
But only this combination needs kernel-addr=0, other images do not need
that with SLOF or VOF.
Everything else LGTM. If no one else has any comment, and you're ok with
these
changes I mentioned, I can amend it myself with my R-b.
I'll probably repost after the other patch with kernel-addr is merged
into your tree. Thanks,
Thanks,
Daniel
+¹ must set kernel-addr=0
+
Build directions
================
--
Alexey