[OpenBIOS] [PATCH 00/11] PReP support for QEMU 40p machine

Mark Cave-Ayland mark.cave-ayland at ilande.co.uk
Sat May 26 21:29:45 CEST 2018

The current PReP firmware provided with OpenBIOS is OpenHackWare which provides
a basic set of OpenFirmware interfaces but does this without providing any kind
of Forth implementation which limits its usefulness and compatibility.

Whilst the project has allowed QEMU PReP development to continue to date, it is
sadly now abandonware with no patches for over 4 years, and with no-one willing
to take on maintenance it is now time for a different approach.

This patchset adds PReP support for the QEMU 40p machine allowing it to start
booting NetBSD and the sandalfoot Linux zImage. The main features required for
this are support for the LSI SCSI controller, resdidual data and PReP boot

In order to test these patches you'll need a recent QEMU with the following
patches applied:

Next you'll need an updated openbios-ppc binary, and for those without access to
a cross-compiler setup I've uploaded the resulting binary to

To boot the sandalfoot zImage from http://www.juneau-lug.org/zImage.initrd.sandalfoot
you can do:

    qemu-system-ppc -M 40p -bios openbios-ppc.prep -cdrom zImage.initrd.sandalfoot
        -boot d
Note that it seems to get stuck trying to initialise the LSI SCSI controller,
presumably due to a bug in the existing QEMU emulation.

NetBSD works much better and in fact boots all the way to userspace:

    qemu-system-pcc -M 40p -bios openbios-ppc.prep -cdrom NetBSD-7.1.2-prep.iso
        -boot d -nographic

In terms of functionality I think this patchset is just about there: there are a
few questions around device names but hopefully someone with real PReP experience
can point me in the right direction.

Finally I've added various people on CC who have expressed interest in PReP and/or
OpenHackWare in the past: if this is no longer of any interest to you, do let me
know and I'll drop your email address from future versions.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland at ilande.co.uk>

Mark Cave-Ayland (11):
  pc_kbd: ensure that we properly reset the 8042 controller and keyboard
  pci: rename i82378 keyboard device from 8042 to keyboard
  pci: add AMD PCNET information to PCI database
  bootcode_load: ensure LOADER_NOT_SUPPORT is returned if no bootcode is
  ppc: add PReP support to dma-map-in
  pci: add driver for LSI 53C810 SCSI controller
  ppc: add PReP residual data block
  ppc: use proper context when pre-loading kernels
  pc-parts: allow successful detection of PReP boot partitions
  libopenbios: add PReP boot partition loader for PPC
  prep: disable VBE extensions when executing client program

 arch/ppc/qemu/context.c         | 129 ++++++-
 arch/ppc/qemu/context.h         |   1 +
 arch/ppc/qemu/init.c            |  34 ++
 arch/ppc/qemu/kernel.h          |   1 -
 arch/ppc/qemu/main.c            |  11 +-
 arch/ppc/qemu/switch.S          |  43 ---
 arch/ppc/qemu/tree.fs           |   5 -
 config/examples/ppc_config.xml  |   2 +
 drivers/build.xml               |   1 +
 drivers/lsi.c                   | 770 ++++++++++++++++++++++++++++++++++++++++
 drivers/pc_kbd.c                |  22 +-
 drivers/pci.c                   |  21 +-
 drivers/pci_database.c          |  14 +
 drivers/pci_database.h          |   1 +
 drivers/vga.fs                  |  11 +
 forth/debugging/client.fs       |   1 +
 include/arch/ppc/residual.h     | 116 ++++++
 include/drivers/drivers.h       |   4 +
 include/drivers/pci.h           |   6 +
 include/libopenbios/prep_load.h |  24 ++
 libopenbios/bootcode_load.c     |   2 +
 libopenbios/build.xml           |   1 +
 libopenbios/initprogram.c       |   8 +
 libopenbios/load.c              |  11 +
 libopenbios/prep_load.c         | 106 ++++++
 packages/pc-parts.c             |  10 +
 26 files changed, 1300 insertions(+), 55 deletions(-)
 create mode 100644 drivers/lsi.c
 create mode 100644 include/arch/ppc/residual.h
 create mode 100644 include/libopenbios/prep_load.h
 create mode 100644 libopenbios/prep_load.c


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