[U-Boot] [PATCH] imx: mx7: Add support for USB boot mode

[Eric Nelson]

Hi Troy,

On 08/29/2017 11:55 AM, Troy Kisky wrote:
> On 8/29/2017 7:37 AM, Eric Nelson wrote:
>> Hi Troy,
>>
>> On 08/28/2017 09:42 AM, Troy Kisky wrote:
>>> On 8/27/2017 3:04 PM, Eric Nelson wrote:
>>>> This adds support for USB boot mode on the i.MX7D SoC, which
>>>> is most useful when doing U-Boot development on this chip.
>>>>
>>>> i.e., it enables you to enter the ROM boot loader's serial
>>>> download protocol using the command:
>>>>
>>>> => bmode usb
>>>>
>>>> Signed-off-by: Eric Nelson <eric at nelint.com>
>>>> ---
>>>>    arch/arm/mach-imx/mx7/soc.c | 2 ++
>>>>    1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/arch/arm/mach-imx/mx7/soc.c b/arch/arm/mach-imx/mx7/soc.c
>>>> index 87bf105..63ee59f 100644
>>>> --- a/arch/arm/mach-imx/mx7/soc.c
>>>> +++ b/arch/arm/mach-imx/mx7/soc.c
>>>> @@ -372,6 +372,8 @@ void set_wdog_reset(struct wdog_regs *wdog)
>>>>     * to SBMR1, which will determine the boot device.
>>>>     */
>>>>    const struct boot_mode soc_boot_modes[] = {
>>>
>>> You might want to add
>>>
>>> +       {"normal",      MAKE_CFGVAL(0x00, 0x00, 0x00, 0x00)},
>>>
>>>
>>> while you're at it, to undo with "bmode normal"
>>>
>>
>> Normal, meaning "don't override"?
>>
>> Why would you want to do this?
>>
>> Please advise,
> 
> Hi Eric!
> 
> 
> If you do "bmode usb" and then use "imx_usb" to load a new u-boot.
> You may want to do "bmode normal", so that a watchdog reset from
> the linux kernel or from u-boot will work as expected, instead of
> starting the ROM USB downloader again.
> 

Got it.

It keeps you from reaching for the power or reset button after
using "bmode usb" or somesuch.

I'll ship a V2 momentarily.

Regards,


Eric