[Qemu-devel] [PATCH 00/31] PPC: mpc8544ds: Create device tree dynamically

[Alexander Graf]

Today we have two separate places where we keep information which device
is where:

  - hw/ppce500_mpc8544ds.c to instantiate all devices
  - pc-bios/mpc8544ds.dtb as device tree to tell the guest about devices

Every time we split crucial information, things can go terribly wrong. If
you update one file, but not the other, you can screw things up without
realizing it quickly.

The redundancy is also unnecessary, because QEMU already knows all the
information at which addresses its devices live. So we can generate the
device tree from the same variables - and even have the device tree adjust
if something changes in there.

The one functionality we lose with this approach is the ability to manually
patch the device tree to contain additional devices. To still be able to do
so easily, we introduce a new option -machine dumpdtb=<file> that creates a
dtb output file which can be used with -machine dtb=<file> later. In between
these 2 executions of QEMU, the dtb can be modified however much you like.

A lot of bits in this patch set are still hardcoded. We also don't accomodate
for dynamic creation of device tree nodes when -device is used. This requires
a bit more QOM'ification for us to be able to loop through all devices, so we
can dynamically create the device tree nodes for them. The basic concept should
still hold as is though.


Alex

v1 -> v2:

  - rename cell64 -> u64
  - don't treat memory as single u64
  - remove commit id from patch description
  - NEW: PPC: e500: Use new MPIC dt format
         PPC: e500: Use new SOC dt format
         PPC: e500: Define addresses as always 64bit
         PPC: e500: Extend address/size of / to 64bit
         dt: Add global option to set phandle start offset
         PPC: e500: Refactor serial dt generation

Alexander Graf (31):
  dt: allow add_subnode to create root subnodes
  dt: add helpers for 2, 3 and 4 cell adds
  dt: add helper for phandle references
  dt: temporarily disable subtree creation failure check
  dt: add helper for phandle enumeration
  dt: add helper for empty dt creation
  dt: add helper for phandle allocation
  dt: add helper for 64bit cell adds
  PPC: e500: require libfdt
  PPC: e500: dt: create memory node dynamically
  PPC: e500: dt: create /cpus node dynamically
  PPC: e500: dt: create /hypervisor node dynamically
  PPC: e500: dt: create / node dynamically
  PPC: e500: dt: create /chosen node dynamically
  PPC: e500: dt: create /soc8544 node dynamically
  PPC: e500: dt: create serial nodes dynamically
  PPC: e500: dt: create mpic node dynamically
  PPC: e500: dt: create global-utils node dynamically
  PPC: e500: dt: create pci node dynamically
  PPC: e500: dt: start with empty device tree
  dt: Add -machine dumpdtb option to dump the current dtb
  PPC: e500: dt: use 64bit cell helper
  PPC: e500: dt: use target_phys_addr_t for ramsize
  PPC: e500: enable manual loading of dtb blob
  Revert "dt: temporarily disable subtree creation failure check"
  PPC: e500: Use new MPIC dt format
  PPC: e500: Use new SOC dt format
  PPC: e500: Define addresses as always 64bit
  PPC: e500: Extend address/size of / to 64bit
  dt: Add global option to set phandle start offset
  PPC: e500: Refactor serial dt generation

 Makefile               |    1 -
 Makefile.target        |    2 +-
 device_tree.c          |  134 +++++++++++++++++++++++++++-
 device_tree.h          |   16 +++
 hw/ppce500_mpc8544ds.c |  237 +++++++++++++++++++++++++++++++++++++++++------
 pc-bios/mpc8544ds.dtb  |  Bin 2028 -> 0 bytes
 pc-bios/mpc8544ds.dts  |  119 ------------------------
 qemu-config.c          |    8 ++
 roms/openbios          |    2 +-
 9 files changed, 365 insertions(+), 154 deletions(-)
 delete mode 100644 pc-bios/mpc8544ds.dtb
 delete mode 100644 pc-bios/mpc8544ds.dts