diff options
| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2022-05-06 15:51:24 +1000 |
|---|---|---|
| committer | Daniel Henrique Barboza <danielhb413@gmail.com> | 2022-05-26 17:11:32 -0300 |
| commit | 162eec18c0aed28eda472bacf207b7b222894169 (patch) | |
| tree | 864e051a133a82167d78d5ce7811b6e1f57cdc68 /docs | |
| parent | 5bb55f3e3b00679519a83ffe688eae0e68e305a7 (diff) | |
spapr/docs: Add a few words about x-vof
The alternative small firmware needs a few words of what it can and
absolutely cannot do; this adds those words.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20220506055124.3822112-1-aik@ozlabs.ru>
[danielhb: added linebreaks before and after table]
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/system/ppc/pseries.rst | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/docs/system/ppc/pseries.rst b/docs/system/ppc/pseries.rst index d9b65ad4e8..3e1bbe6726 100644 --- a/docs/system/ppc/pseries.rst +++ b/docs/system/ppc/pseries.rst @@ -32,14 +32,43 @@ 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 | ✓ | ✓ | ++-------------------+-------------------+------------------+ + +¹ must set kernel-addr=0 + Build directions ================ |