[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 11:59 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 26 May 2015 at 21:55, Bin Meng <bmeng.cn at gmail.com> wrote:
>> 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.
>
> I think it is OK. But another option would be to add an IDE node to
> the device tree and check it when CONFIG_OF_CONTROL is defined...
>

I feel that we need convert all block drivers to driver model, so that
the driver can probe and initialize IDE/AHCI based on device tree
node. But I guess that's a long term goal?

Regards,
Bin