Re: question about uboot mt7620 RAM_VERSION

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@waav.com mailto:klu@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@denx.de
<mailto:sr@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