[U-Boot] [PATCH 5/6] x86: qemu: Create i440fx and q35 board configuration and device tree

[Bin Meng]

Hi Simon,

On Wed, May 27, 2015 at 11:13 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 25 May 2015 at 08:36, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Although the two qemu-x86 targets (i440fx and q35) share a lot in
>> common, they still have something that cannot easily handled in one
>> place (like different configurations, different properties in the
>> device tree). Split to create two dedicated board configuration and
>> device tree files and make the i440fx be the default build target.
>>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>
>>  arch/x86/dts/Makefile                             |  3 +-
>>  arch/x86/dts/qemu-x86_i440fx.dts                  | 34 +++++++++++++++
>>  arch/x86/dts/{qemu-x86.dts => qemu-x86_q35.dts}   |  2 +-
>>  board/coreboot/coreboot/Kconfig                   |  4 +-
>>  board/emulation/qemu-x86/Kconfig                  | 19 +++++++--
>>  configs/qemu-x86_defconfig                        |  1 -
>>  doc/README.x86                                    | 13 +++++-
>>  include/configs/{qemu-x86.h => qemu-x86_i440fx.h} | 20 ++-------
>>  include/configs/qemu-x86_q35.h                    | 52 +++++++++++++++++++++++
>>  9 files changed, 122 insertions(+), 26 deletions(-)
>>  create mode 100644 arch/x86/dts/qemu-x86_i440fx.dts
>>  rename arch/x86/dts/{qemu-x86.dts => qemu-x86_q35.dts} (95%)
>>  rename include/configs/{qemu-x86.h => qemu-x86_i440fx.h} (78%)
>>  create mode 100644 include/configs/qemu-x86_q35.h
>
> Do we need a separate config file? It would be good if all the changes
> were in the device tree so that we don't need a separate config. Or at
> least that the configs are the same except for the device tree.
>

So far the only difference between two separate config files are the
ATA/SATA settings. i440fx has legacy IDE support while q35 has the
AHCI support. We can enable them both in just one config files,
however turning on legacy IDE support on q35 causes significant boot
delay as the legacy IDE driver has some big timeout in probing the
attached devices. Do you think this is something we are tolerant of?
If yes, I can just do separate device trees.

Regards,
Bin