Re: [Qemu-devel] [PATCH] allwinner-a10: add config script support

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 12/26/2013 01:58 AM, Li Guang wrote:
> Peter Maydell wrote:
>> On 26 December 2013 00:39, Li Guang<lig.fnst@cn.fujitsu.com>  wrote:
>>> Peter Maydell wrote:
>>>> On 26 December 2013 00:14, Li Guang<lig.fnst@cn.fujitsu.com>   wrote:
>>>>> it's the approach sunxi-linux kernel config hardware,
>>>>> the binary is actually a transformed text script,
>>>>> and context of script is like:
>>>>>
>>>>> [card0_boot_para]
>>>>> card_ctrl = 0
>>>>> card_high_speed = 1
>>>>> card_line = 4
>>>>> sdc_d1 = port:PF00<2><1><default><default>
>>>>> sdc_d0 = port:PF01<2><1><default><default>
>>>>> sdc_clk = port:PF02<2><1><default><default>
>>>>> sdc_cmd = port:PF03<2><1><default><default>
>>>>> sdc_d3 = port:PF04<2><1><default><default>
>>>>> sdc_d2 = port:PF05<2><1><default><default>
>>>>>
>>>> So what sets this up on real hardware? Is this part of
>>>> a firmware blob? Is it in ROM or flash?
>>> it's generally in /boot, bootloader will load it
>>> into ram address 0x43000000, kernel will find it
>>> at this fixed address, and parse it, learn the hardware
>>> related configuration, mostly property of devices, and
>>> GPIOes used.
>> Weird. Why isn't this just using devicetree?
>
> don't know the exactly reason linux-sunxi community
> do this(actually, the script parsing code mostly wrote
> by engineer from Allwinner).

I'm one of the linux-sunxi developers, the only reason we've
this fex file abomination, is because we've inherited it
from the android-allwinner sources.

Currently most of the linux-sunxi developers are no longer
focusing on the 3.4 android/allwinner derived sources we
maintain. They are currently in a "good enough for everyday
use" state.

So now most of us are focusing on getting *proper* sunxi
SoC support upstream. This is using device-tree. Currently
we've working timers, interrupt-controller, uarts, mmc,
sata, nic (both 100mbit and Gbit variants), ehci controller
and builtin rtc support with upstream kernels. Which I
believe likely covers everything the qemu emulation offers
atm. For those interested, see:
https://github.com/linux-sunxi/linux-sunxi/commits/sunxi-devel

And the mailinglist reports about progress in that branch.

 From the linux-sunxi pov fex files are a legacy thing which
will go away in the future.

Regards,

Hans