question about uboot mt7620 RAM_VERSION

[Stefan Roese]

Hi Kang-sen,

On 24.10.22 19:58, Kang-sen Lu wrote:
> I am wondering if you have read my reply on 10/18. It is very strange to 
> find that unless I had uboot to do a saveenv, the RAM_VERSION uboot.bin 
> would not run properly in DRAM.

Frankly, I don't really understand this message. It's not clear to
me, what you are doing and what is working and what is failing.

I thought you were trying to boot the current mainline U-Boot RAM
version u-boot.bin. If yes, which build target did you use? What
does it show on the serial console?

Thanks,
Stefan

> Thanks.
> 
> Kang-sen
> 
> On Tue, Oct 18, 2022 at 10:05 AM Kang-sen Lu <klu at waav.com 
> <mailto:klu at waav.com>> wrote:
> 
>     Hi, Stefan:
> 
>     Thanks for your reply.
> 
>     The uboot in the zbtlink mt7620 router has the signatures follows:
> 
>     U-Boot 1.1.3 (Nov  9 2016 - 15:34:50)
> 
>     SoC:MediaTek MT7620
>     DRAM:  Memory Testing..131072K OK. is 128 MB
>     relocate_code Pointer at: 87fb0000
>     enable ephy clock...done. rf reg 29 = 5
>     SSC disabled.
>     spi_wait_nsec: 29
>     spi device id: ef 40 18 0 0 (40180000)
>     Flash: W25Q128BV
> 
>     I would like to share my strange experience about RAM version uboot
>     for mt7620. By pure luck, I found that when I tried to load a newly
>     built uboot with startup menu option 8, unless I change the
>     filename, say, from uboot.bin to uboot1.bin, the newly loaded uboot
>     would not startup properly in RAM.
> 
>     I don't have the knowledge to find out why this variable "modifies"
>     to be none-zero is so important to the execution of uboot in RAM.
>     Maybe some expert in this group can easily figure that out.
> 
>     Thanks.
> 
>     Kang-sen
> 
>     On Tue, Oct 18, 2022 at 7:53 AM Stefan Roese <sr at denx.de
>     <mailto:sr at denx.de>> wrote:
> 
>         Hi Kang-sen,
> 
>         (added Weijie Gao to Cc)
> 
>         On 17.10.22 14:11, Kang-sen Lu wrote:
>          >   I am building uboot.bin for mt7620 router.
>          >
>          > I used start menu option 8, a hidden one choice, to load
>         uboot.bin through
>          > tftp.
>          >
>          > The tftp transfer is OK. But when the new uboot starts, it hang.
> 
>         So which mainline U-Boot build target did you use? Don't you see
>         any output on the serial console at all?
> 
>          > I am wondering if the RAM_VERSION for mt7620 still works.
> 
>         In mainline U-Boot this is usually handled this way. The SPL U-Boot
>         version is responsible for the low-level HW init, like DRAM/DDR init
>         etc. It's hard to impossible to chainload this SPL part from a
>         running U-Boot version.
> 
>         The "RAM_VERSION" is usually the main U-Boot proper image
>         "u-boot.bin".
>         So in general you are using the correct file here. Even though I
>         have
>         not idea, if the build target is correct for your "mt7620 router".
> 
>         Thanks,
>         Stefan
> 

Viele Grüße,
Stefan Roese

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