question about uboot mt7620 RAM_VERSION

Stefan Roese sr at denx.de
Wed Oct 26 07:36:04 CEST 2022


Hi Kang-sen,

On 25.10.22 21:40, Kang-sen Lu wrote:
> I am sorry that I was working on an old uboot version. You mentioned 
> that you have ported uboot to my7620. I would like to download it. Is it 
> available at this site? https://github.com/u-boot/u-boot 
> <https://github.com/u-boot/u-boot>.

Unfortunately it's not that easy. As your specific board (router) needs
to get ported to upstream U-Boot. It might be the case, that at least
the RAM version of the currently supported MT7620 board "mt7620_rfb"
works for you. But this is very unlikely - sorry, I don't know this
board and your router in detail.

I've compiled the binaries for the mt7620_rfb and attached the resulting
u-boot.bin, which might work as a RAM target for you. Just give it a
try. The TEXT_BASE is 0x80200000, so you should load and boot it from
there:

=> tftp 0x80200000 u-boot.bin
=> go 0x80200000

Let me know if this produces some output or crashes directly.

Thanks,
Stefan

> Thanks.
> 
> Kang-sen
> 
> On Tue, Oct 25, 2022 at 10:47 AM Stefan Roese <sr at denx.de 
> <mailto:sr at denx.de>> wrote:
> 
>     Hi Kang-sen,
> 
>     On 25.10.22 15:25, Kang-sen Lu wrote:
>      > Thanks for your reply.
>      >
>      > I cloned the uboot source code from here:
>      > https://github.com/tessel/uboot-mt7620
>     <https://github.com/tessel/uboot-mt7620>
>      > <https://github.com/tessel/uboot-mt7620
>     <https://github.com/tessel/uboot-mt7620>>
>      >
>      > I built the uboot.bin for RAM_VERSION. If I select option 8 at
>     power up
>      > with the uboot from zbtlink, the new uboot.bin will hang. But if I
>      > caused saveenv() to happen, by changing tftp filename
>     artificially, the
>      > uboot.bin for RAM_VERSION will start and run properly, by the
>     uboot from
>      > zbtlink.
> 
>     Sorry, this is the ancient U-Boot version. I thought you were talking
>     about the mainline U-Boot version, which I ported for MT7620/80 some
>     years ago (with many extensions and fixes by Weijie later on).
> 
>     I don't remember the details of this ancient MT7620 U-Boot version
>     and frankly don't want to dig into this (again).
> 
>      > Maybe Weijie can comment on the experimental result?
> 
>     Maybe.
> 
>      > Thanks.
>      >
>      > Kang-sen
>      >
>      > BTW: How does uboot developer usually run the RAM_VERSION
>     uboot.bin, I
>      > am curious. Is it loaded with tftp server, or something else?
> 
>     Yes. This is very handy and frequently done. Load the RAM version
>     into RAM to the TEXT_BASE address and start it from there via the
>     "go" command.
> 
>     BTW: Please keep the ML on Cc. It might be that someone else has
>     some answers. Or that this topic is interesting for other
>     people as well.
> 
>     Thanks,
>     Stefan
> 
>      > On Tue, Oct 25, 2022 at 12:46 AM Stefan Roese <sr at denx.de
>     <mailto:sr at denx.de>
>      > <mailto:sr at denx.de <mailto:sr at denx.de>>> wrote:
>      >
>      >     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>
>      >     <mailto:klu at waav.com <mailto:klu at waav.com>>
>      >      > <mailto:klu at waav.com <mailto:klu at waav.com>
>     <mailto: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>
>      >     <mailto:sr at denx.de <mailto:sr at denx.de>>
>      >      >     <mailto:sr at denx.de <mailto:sr at denx.de>
>     <mailto: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
>      >
>      >     --
>      >     DENX Software Engineering GmbH,      Managing Director:
>     Wolfgang Denk
>      >     HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell,
>     Germany
>      >     Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email:
>      > sr at denx.de <mailto:sr at denx.de> <mailto:sr at denx.de
>     <mailto:sr at denx.de>>
>      >
> 
>     Viele Grüße,
>     Stefan Roese
> 
>     -- 
>     DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
>     HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>     Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email:
>     sr at denx.de <mailto:sr at denx.de>
> 

Viele Grüße,
Stefan Roese

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr at denx.de
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