[PATCH v3 2/2] imx8mn/8mp: Allow booting via USB

[Tim Harvey]

On Thu, Apr 21, 2022 at 11:06 AM Fabio Estevam <festevam at gmail.com> wrote:
>
> From: Fabio Estevam <festevam at denx.de>
>
> When trying to boot via USB on i.MX8MN it is necessary to specify
> the U-Boot environment location, otherwise the boot process simply
> hangs.
>
> Specify the environment location when booting from USB.
>
> Tested on a imx8mn-evk.
>
> Suggested-by: Michael Nazzareno Trimarchi <michael at amarulasolutions.com>
> Signed-off-by: Fabio Estevam <festevam at denx.de>
> ---
> Changes since v2:
> - Handle explicitly the CONFIG_ENV_IS_NOWHERE case and return
> ENVL_UNKNOWN as fallback (Marek).
>
>  arch/arm/mach-imx/imx8m/soc.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
> index 7059d87e336b..34a07b53e57a 100644
> --- a/arch/arm/mach-imx/imx8m/soc.c
> +++ b/arch/arm/mach-imx/imx8m/soc.c
> @@ -1536,6 +1536,16 @@ enum env_location arch_env_get_location(enum env_operation op, int prio)
>                 return ENVL_UNKNOWN;
>
>         switch (dev) {
> +       case USB_BOOT:
> +               if (IS_ENABLED(CONFIG_ENV_IS_IN_SPI_FLASH))
> +                       return ENVL_SPI_FLASH;
> +               if (IS_ENABLED(CONFIG_ENV_IS_IN_NAND))
> +                       return ENVL_NAND;
> +               if (IS_ENABLED(CONFIG_ENV_IS_IN_MMC))
> +                       return ENVL_MMC;
> +               if (IS_ENABLED(CONFIG_ENV_IS_NOWHERE))
> +                       return ENVL_NOWHERE;
> +               return ENVL_UNKNOWN;
>         case QSPI_BOOT:
>         case SPI_NOR_BOOT:
>                 if (IS_ENABLED(CONFIG_ENV_IS_IN_SPI_FLASH))
> --
> 2.25.1
>

Fabio,

Thanks - this at least allows me to boot on imx8mp-venice-gw74xx
without needing to enable CONFIG_ENV_IS_NOWHERE.

I do however notice when I do so env is attempted to load from MMC dev
0 (CONFIG_ENV_IS_IN_MMC=y) - what controls the device number in this
case as for this board, the emmc is dev 2.

U-Boot SPL 2022.04-00073-g9d2b56e8338a (Apr 25 2022 - 12:35:37 -0700)
DRAM    : LPDDR4 4 GiB
WDT:   Started watchdog at 30280000 with servicing (60s timeout)
Trying to boot from BOOTROM
Find img info 0x48025c00, size 1396
Need continue download 1024
DTB     : imx8mp-venice-gw74xx
Download 873624, Total size 875672
NOTICE:  BL31: v2.4(release):f884ad7b0ba2
NOTICE:  BL31: Built : 14:00:19, Mar 17 2022


U-Boot 2022.04-00073-g9d2b56e8338a (Apr 25 2022 - 12:35:37 -0700)

CPU:   Freescale i.MX8MP[8] rev1.1 1600 MHz (running at 1200 MHz)
CPU:   Industrial temperature grade (-40C to 105C) at 46C
Reset cause: POR
Model: Gateworks Venice GW74xx i.MX8MP board
DRAM:  4 GiB
clk_register: failed to get osc_32k device (parent of usb_root_clk)
Core:  211 devices, 24 uclasses, devicetree: separate
WDT:   Started watchdog at 30280000 with servicing (60s timeout)
MMC:   FSL_SDHC: 2
Loading Environment from MMC... MMC Device 0 not found
*** Warning - No MMC card found, using default environment

In:    serial at 30890000
Out:   serial at 30890000
Err:   serial at 30890000
Net:   KSZ9897S: eth2: lan1, eth3: lan2, eth4: lan3, eth5: lan4, eth6:
lan5, eth1: ethernet at 30be0000, eth0: ethernet at 30bf0000

Best Regards,

Tim