[U-Boot] [PATCH] x86: Clean up SPI flash drivers in defconfig

[Bin Meng]

Hi Simon,

On Wed, Dec 2, 2015 at 12:32 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 28 November 2015 at 05:45, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Every board has one dedicated type of SPI flash, hence it is
>> unnecessary to include multiple SPI flash drivers.
>>
>> For QEMU and coreboot (default build of coreboot is also QEMU),
>> SPI flash is not supported. Remove those SPI flash drivers.
>>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>
>>  configs/bayleybay_defconfig         | 2 --
>>  configs/chromebook_link_defconfig   | 2 --
>>  configs/chromebox_panther_defconfig | 2 --
>>  configs/coreboot-x86_defconfig      | 4 ----
>>  configs/crownbay_defconfig          | 3 ---
>>  configs/galileo_defconfig           | 2 --
>>  configs/minnowmax_defconfig         | 3 ---
>>  configs/qemu-x86_defconfig          | 4 ----
>>  8 files changed, 22 deletions(-)
>
> What is the benefit of this? I see it removes a few lines in a data
> table. Does it matter?

Maybe we should ask the other way around, why do we create so many
flash driver Kconfig option? I believe the intention was footprint.
Besides the footprint issue, having just one flash driver in each
board makes it very clear instead of causing confusion. Looks other
board defconfig files only select one.

>
> For all of these platforms we can use the dediprog em100 which I
> typically set to use winbond as the manufacturer, regardless of which
> chip is actually on the board.
>

I think that's because emulator can emulate flash from various vendors.

> For U-Boot on coreboot, why is SPI flash not supported? It certainly
> works with link.

Yes, booting from coreboot does support SPI flash. However since we
decided to use QEMU as the default build target for coreboot, and QEMU
does not support SPI flash yet, these config options are removed. One
can certainly adjust these Kconfig options via 'make menuconfig', eg:
adding SD/MMC support which is not in coreboot's defconfig either.

Regards,
Bin