im8mn: Loading U-Boot via serial download mode

[Michael Nazzareno Trimarchi]

Hi

Il mer 20 apr 2022, 21:49 Adam Ford <aford173 at gmail.com> ha scritto:

> On Wed, Apr 20, 2022 at 2:40 PM Fabio Estevam <festevam at gmail.com> wrote:
> >
> > Hi Adam,
> >
> > Looking at your imx8mn beacon patches, it seems you managed to boot
> > the imx8mn beacon board via serial download mode.
> >
> > I am trying to achieve the same on an imx8mn-evk running top of tree
> > U-Boot and added the following changes:
> >
> > --- a/configs/imx8mn_evk_defconfig
> > +++ b/configs/imx8mn_evk_defconfig
> > @@ -50,11 +50,22 @@ CONFIG_CMD_GPIO=y
> >  CONFIG_CMD_I2C=y
> >  CONFIG_CMD_MMC=y
> >  CONFIG_CMD_CACHE=y
> > +CONFIG_USB=y
> > +# CONFIG_SPL_DM_USB is not set
> > +CONFIG_USB_EHCI_HCD=y
> > +CONFIG_USB_GADGET=y
> > +CONFIG_USB_GADGET_MANUFACTURER="FSL"
> > +CONFIG_USB_GADGET_VENDOR_NUM=0x0525
> > +CONFIG_USB_GADGET_PRODUCT_NUM=0xa4a5
> > +CONFIG_CI_UDC=y
> > +CONFIG_SDP_LOADADDR=0x0
> > +CONFIG_OF_LIBFDT_OVERLAY=y
> >  CONFIG_CMD_REGULATOR=y
> >  CONFIG_CMD_EXT4_WRITE=y
> >  CONFIG_OF_CONTROL=y
> >  CONFIG_SPL_OF_CONTROL=y
> >  CONFIG_ENV_OVERWRITE=y
> > +CONFIG_ENV_IS_NOWHERE=y
> >  CONFIG_ENV_IS_IN_MMC=y
> >  CONFIG_SYS_RELOC_GD_ENV_ADDR=y
> >  CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
> >
> > Then I put the board into serial download mode and I run:
> >
> > $ sudo uuu flash.bin
> >
> > The following output appears on the console:
> >
> > U-Boot SPL 2022.04-00856-g246e03476ba3-dirty (Apr 20 2022 - 16:24:48
> -0300)
> > SEC0:  RNG instantiated
> > Normal Boot
> > WDT:   Started watchdog at 30280000 with servicing (60s timeout)
> > Trying to boot from BOOTROM
> > Find img info 0x&48020a00, size 872
> > Need continue download 1024
> > Download 694696, Total size 696232
> > NOTICE:  BL31: v2.2(release):rel_imx_5.4.47_2.2.0-0-gc949a888e909
> > NOTICE:  BL31: Built : 16:07:45, Apr 20 2022
> >
> > What would be the other uuu command that needs to be run so that
> > U-Boot proper can be loaded?
>
> I had to set the environmental variable for ENV is nowhere.  There was
> a bunch of discussion about the fact that the 8MN and 8MP have some
> special code which makes the environmental variable location depend on
> the boot device.  A few of us went a few rounds, but Marek didn't like
> our solution.
>
> Set CONFIG_ENV_IS_NOWHERE=y and rebuild.  It will likely boot.
>

That code should be dropped because it's really buggy. We already sent
several patches. I prefer some registered mechanism and not those board,
arch etc function definition.

Michael

>
> adam
> >
> > Thanks,
> >
> > Fabio Estevam
>