[U-Boot] Uboot send pull request

[Rick Chen]

Bin Meng <bmeng.cn at gmail.com> 於 2018年11月27日 週二 下午5:54寫道：
>
> Hi Rick,
>
> On Wed, Nov 21, 2018 at 4:53 PM Rick Chen <rickchen36 at gmail.com> wrote:
> >
> > Bin Meng <bmeng.cn at gmail.com> 於 2018年11月21日 週三 下午3:18寫道：
> > >
> > > Hi Rick,
> > >
> > > On Wed, Nov 21, 2018 at 2:00 PM Rick Chen <rickchen36 at gmail.com> wrote:
> > > >
> > > > > >
> > > > > > Do any of your above patches get v2 posted? At least I did not see any follow-up
> > > > > > response [1] regarding to "riscv: ax25-ae350: Pass dtb address to u-boot with a1
> > > > > > register"
> > > >
> > > > First of all you told me about that
> > > > board_fdt_blob_setup() should be completely removed.
> > > > Instead the simple fix should be add CONFIG_OF_PRIOR_STAGE
> > > > to ax25-ae350_defconfig.
> > > >
> > > > Then I explain you about that is for booting from flash.
> > > > And you said
> > > > In this case, we need support OF_CONTROL like other arch, eg:
> > > > CONFIG_OF_EMBED and CONFIG_OF_SEPARATE.
> > > >
> > > > In README, I don't find the limitation about when booting from flash,
> > > > it can not use  CONFIG_OF_BOARD.
> > > >
> > >
> > > Correct. However, when ax25-ae350's U-Boot boots from ROM, where does
> > > prior_stage_fdt_address get assigned to the ROM address? Besides, this
> > > variable is declared in fdtdec.h as follows:
> > >
> > > #if CONFIG_IS_ENABLED(OF_PRIOR_STAGE)
> > > extern phys_addr_t prior_stage_fdt_address;
> > > #endif
> > >
> > > It means only OF_PRIOR_STAGE will use this variable. But in your patch
> >
> > I have seen that declaration in fdtdec.h
> > But I was referred to
> > include\configs\bcmstb.h
> > extern phys_addr_t prior_stage_fdt_address;
> > and that is why I borrow prior_stage_fdt_address.
> >
>
> It looks to me that bcmstb.h was an ad-hoc hack of using
> prior_stage_fdt_address. I don't think it was originally meant to do
> such. It intends to work with OF_PRIOR_STAGE only.
>

I just refer to
bcmstb.c
phys_addr_t prior_stage_fdt_address BCMSTB_DATA_SECTION;
bcmstb.h
extern phys_addr_t prior_stage_fdt_address;

That is why I borrow and recycle to use it.


> > You do not point out this consideration directly, maybe that is why
> > we have some thinking is different.
> >
>
> Sorry I wasn't that clear, as I was expecting we continue discussing
> on that patch thread.
>

Yes.
I have reply some of your questions in another email.
Maybe we can move there and discuss further more. :)

Re: [PATCH v5 4/4] riscv: Remove redundant a2 store on DRAM base in start.S
https://www.mail-archive.com/u-boot@lists.denx.de/msg307101.html

B.R
Rick


> > > this was borrowed to support OF_BOARD, which is confusing I think. If
> > > U-Boot boots from reset vector, the canonical way to support DT is via
> > > CONFIG_OF_EMBED or CONFIG_OF_SEPARATE.
> > >
> > > > That is why ax25-ae350 use
> > > > CONFIG_OF_BOARD to support boot from RAM and ROM.
> > > > It is a flexible approach to meet Andes' HW mechanism.
> > > >
> > > > I think it is a configuration in ax25-ae350_defconfig.
> > > > It will not affect qemu-riscv32(64)_defconfig.
> > > >
> > >
> > > I understand it does not affect qemu riscv board. The thing is that I
> > > wasn't clear why you did that way for ax25-ae350.
> >
> > Actually I just want to remove the redundant code in start.S
> > -       li      t0, CONFIG_SYS_SDRAM_BASE
> > -       SREG    a2, 0(t0)
> > so borrowed prior_stage_fdt_address in CONFIG_OF_BOARD
> >
>
> Regards,
> Bin